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<html>
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<head><title>Natural Estrogens</title></head>
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<body>
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<h1>
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Natural Estrogens
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</h1>
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<p>
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The fact that an extremely large number of naturally occurring compounds, and an unlimited number of
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synthetic compounds, have an estrogen-like activity has been exploited by the drug companies to produce
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patented proprietary drugs, especially the contraceptives.
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</p>
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<p>
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The promotion of "natural estrogens" is a new marketing strategy that capitalizes on the immense promotional
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investment of the drug companies in the concept of estrogen replacement as "therapy."
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</p>
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<p>
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<hr />
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</p>
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<p>
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<strong>"Whether weak or strong, the estrogenic response of a chemical, if not overcome, will add extra
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estrogenic burden to the system. At elevated doses, natural estrogens and environmental estrogen-like
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chemicals are known to produce adverse effects. The source of extra or elevated concentration of
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estrogen could be either endogenous or exogenous.</strong> The potential of exposure for humans and
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animals to environmental estrogen-like chemicals is high."
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</p>
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<p>D. Roy, et al., 1997</p>
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<p>
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<hr />
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<hr />
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</p>
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<p>
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Estrogen marketing has entered a new phase, based on the idea of "specific estrogen-receptor modulators,"
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the idea that a molecule can be designed which has estrogen's "good qualities without its bad qualities."
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This specific molecule will be "good for the bones, the heart, and the brain," without causing cancer of the
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breast and uterus, according to the estrogen industry. Meanwhile, soybeans are said to contain estrogens
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that meet that goal, and it is often said that "natural estrogens" are better than "synthetic estrogens"
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because they are "balanced."
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</p>
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<p>
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Estrogen's effects on cells are immediate and profound, independent of the "estrogen receptors."
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</p>
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<p>
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Japanese women's relative freedom from breast cancer is independent of soy products<strong>:</strong>
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traditional soy foods aren't the same as those so widely used in the US, for example, soy sauce doesn't
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contain the so-called soy estrogens, and tea is used much more commonly in Japan than in the US, and
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contains health protective ingredients. The "estrogenic" and "antioxidant" polyphenolic compounds of tea are
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not the protective agents (they raise the level of estrogen), but tea's <em>caffeine</em> is a very powerful
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and general anti-cancer protectant. The influential article in <em>
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Lancet</em> (D. Ingram, <em>Lancet</em> 1997;<em>350</em>:990-994. "Phytoestrogens and their role in
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breast cancer,"<em>
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Breast NEWS: Newsletter of the NHMRC National Breast Cancer Centre, Vol. 3,</em> No. 2, Winter 1997)
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used a method known to produce false results, namely, comparing the phytoestrogens (found in large amounts
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in soybeans) in the urine of women with or without breast cancer. For over fifty years, it has been known
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that the liver excretes estrogens and other toxins from the body, and that when (because of liver inertia)
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estrogen isn't excreted by the liver and kidneys, it is retained in the body. This process was observed in
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both animals and humans decades ago, and it is <em>also well established that estrogen itself suppresses the
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detoxifying systems, causing fewer carcinogens to be excreted</em> in the urine. Ingram's evidence
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logically would suggest that the women who have cancer are failing to eliminate estrogens, including
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phytoestrogens, at a normal rate, and so are retaining a higher percentage of the chemicals consumed in
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their diets. Flavonoids and polyphenols, like our own estrogens, suppress the detoxifying systems of the
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body.
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</p>
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<p>
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Our bodies produce estrogen in a great variety of tissues, not just in the ovaries. Fat cells are a major
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source of it. The tendency to gain weight after puberty is one of the reasons that women's estrogen levels
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rise with aging throughout the reproductive years, though this isn't the basic reason for estrogen's
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lifelong growing influence, even in men.
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</p>
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<p>
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Our diets provide very significant, if not always dangerous, amounts of estrogen. "Weak estrogens" generally
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have the full range of harmful estrogenic effects, and often have additional toxic effects. American women
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who eat soy products undergo changes that appear to predispose them to cancer, making their tissues even
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more unlike those of the relatively breast-cancer resistant Japanese than they were before eating the soy
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foods.
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</p>
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<p>
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People under stress, or who have a thyroid deficiency, or who don't eat enough protein, typically have
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elevated estrogen levels. The accumulation of the "essential fatty acids," the polyunsaturated oils, in the
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tissues promotes the action of estrogen in a variety of ways, and this effect of diet tends to be
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cumulative, and to be self-accelerating.
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</p>
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<p>
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Science is a method that helps us to avoid believing things that are wrong, but there is a distinct herd
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instinct among people who "work in science," which makes it easy to believe whatever sounds plausible, if a
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lot of other people are saying it is true. This is just as evident in physics as it is in medicine.
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Sometimes powerful economic interests help people to change their beliefs, for example as the insurance
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industry helped to convince the public of the dangers of smoking. Two of the biggest industries in the
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world, the estrogen industry and the soy bean industry, spend vast amounts of money helping people to
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believe certain plausible-sounding things that help them sell their products. Sometimes they can achieve
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great things just by naming the substance.
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</p>
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<p>
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Estrogenicity can be defined most simply as "acting the way estrogen does," (originally, the term "estrogen"
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meant "producing estrus," the female readiness to mate) and since our natural estrogen does many things, the
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definition is often, for practicality, based on the rapid changes produced in certain female organs by
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estradiol, specifically, the enlargement of the uterus by first taking up a large amount of water, and
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secondarily by the multiplication of cells and the production of specific proteins. A similar process
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occurring in the breast is also recognized as an important feature of the estrogen reaction, but as we try
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to define just what "estrogenicity" is, we see that there is something deeply wrong with this method of
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defining a hormone, because we are constantly learning more about the actions of estrogen, or of a specific
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form of the molecule. Calling it "the female hormone" distracted attention from its many functions in the
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male, and led to great confusion about its antifertility actions and its other toxicities. Many biologists
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called it "folliculin," because of the ovarian follicle's significant role in its production, but the
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pharmaceutical industry succeeded in naming it in relation to <strong><em>
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one</em></strong> of its functions, and then in extending that idea of it as "the producer of female
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receptivity" to the even more misleading idea that it is "the female hormone." But when people speak about
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the "estrogenicity" of a substance, they mean that it has properties that parallel those of "folliculin,"
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the particular group of ovarian hormones that includes estradiol, estrone, and estriol.
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</p>
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<p>
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Over the last 100 years, thousands of publications about estrogen's toxicity have created a slight
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resistance to the consumption of the major estrogen products. One ploy to overcoming this resistance is to
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call certain products "natural estrogen," as distinguished from "synthetic estrogens." The <strong
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>three</strong>
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<strong>main estrogens in our bodies are estradiol, estrone, and estriol, though there are many other minor
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variants on the basic molecule.</strong> These three estrogens, singly or in combinations, are being
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sold as natural estrogens, with their virtues explained in various ways. Implicit in many of these
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explanations, is the idea that these are safer than synthetics. They are sometimes contrasted to the "horse
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estrogen" in Premarin, as if they are better because they are like the estrogens that people produce. But it
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was exactly the normal human estrogens, produced by the ovaries, that led to the basic discoveries about the
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toxicity of estrogen, its ability to produce cancer in any organ, to cause seizures, blood clots, birth
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defects, accelerated aging, etc.
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</p>
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<p>
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Although I would suppose that a hormone from a horse might be "more natural" for a person's body than a
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hormone from a plant, the word "natural" as used in the phrases "natural food store," or "natural medicine,"
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has come to be associated strongly with things derived from plants. The health food industry, now largely
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taken over by giant corporations to sell products that weren't producing as much revenue when sold in
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supermarkets and drugstores, has helped to create a culture in which botanical products are thought to be
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especially good and safe. Naturally grown free-range chickens used to be favored, because they could eat
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anything they wanted, but now eggs laid by factory chickens, eating an industrial corn-and-soy diet, are
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from "vegetarian chickens," because the marketers know the public will favor eggs that have the vegetarian
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mystique.
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</p>
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<p>
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Biologically active molecules have both general and specific properties. Estrogenicity is a general
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property, but all molecules which have that property also have some other specific properties. Estriol is a
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little more water soluble than estrone, so it interacts with every body system in a slightly different way,
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entering oily environments with slightly less ease, etc.
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</p>
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<p>
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The estrogen which occurs in yeasts, estradiol, is identical to the major human estrogen, and it is thought
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to have a reproductive function in yeasts, though this isn't really understood. A feature of this molecule,
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and of all other molecules that "act like estrogen," is the phenolic function, an oxygen and hydrogen group
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attached to a resonant benzene ring. Phenol itself is estrogenic, and the phenolic group is so extremely
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common in nature that the number of existing estrogenic substances is great, and the number of potential
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molecules with estrogen-function is practically infinite.
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</p>
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<p>
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The phenolic group has many biological functions. For example, it commonly functions as an "antioxidant,"
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though something which functions as an antioxidant in one situation is often a pro-oxidant in another
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situation. The molecule can have catalytic, germicidal, aromatic, neurotropic, and other functions. But it
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also always has, to some degree, the "estrogenic" function. This overlap of functions probably accounts for
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why so many plants have significant estrogenic activity. (Natural estrogens, like other phenolics, including
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the flavonoids, are also mutagenic.)
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</p>
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<p>
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The estrogenic properties of legumes were studied when sheep farmers found that their sheep miscarried when
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they ate clover. (I think it's interesting how this terribly toxic effect has been neglected in recent
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decades.) All legumes have this property, and all parts of the plant seem to contain some of the active
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chemicals. In beans, several substances have been found to contribute to the effect. The estrogenic effects
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of the seed oils and the isoflavones have been studied the most, but the well-known antithyroid actions
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(again, involving the oils, the isoflavones, and other molecules found in legumes) have an indirect
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estrogen-promoting action, since hypothyroidism leads to hyperestrogenism. (Estrogens are known to be
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thyroid suppressors, so the problem tends to be self-accelerating.)
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</p>
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<p>
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The various specific actions of the many estrogenic substances in beans and other legumes haven't been
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throughly studied, but there is evidence that they are also--like estrogen itself--both mutagenic and
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carcinogenic.
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</p>
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<p>
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The estrogen-promoting actions of soy oil apply to <strong>all of the commonly used polyunsaturated fatty
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acids. The same fatty acids that suppress thyroid function, have estrogenic effects.</strong>
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</p>
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<p>
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The isoflavones (many of which are now being promoted as "antioxidants" and "cancer preventives") are toxic
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to many organs, but they have clear estrogenic effects, and are active not only immediately in the mature
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individual, but when they are present prenatally, they cause feminization of the male genitalia and
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behavior, and early maturation of the female offspring, with the tissue changes that are known to be
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associated with increased incidence of cancer.
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</p>
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<p>
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There are interesting associations between vegetable "fiber" and estrogens. Because of my own experience in
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finding that eating a raw carrot daily prevented my migraines, I began to suspect that the carrot fiber was
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having both a bowel-protective and an antiestrogen effect. Several women who suffered from premenstrual
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symptoms, including migraine, had their serum estrogen measured before and after the "carrot diet," and they
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found that the carrot lowered their estrogen within a few days, as it relieved their symptoms.
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</p>
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<p>
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Undigestible fiber, if it isn't broken down by bowel bacteria, increases fecal bulk, and tends to speed the
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transit of material through the intestine, just as laxatives do. But some of these "fiber" materials, e.g.,
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lignin, are themselves estrogenic, and other fibers, by promoting bacterial growth, can promote the
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conversion of harmless substances into toxins and carcinogens. When there is a clear "antiestrogen" effect
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from dietary fiber, it seems to be the result of accelerated transit through the intestine, speeding
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elimination and preventing reabsorption of the estrogen which has been excreted in the bile. Laxatives have
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this same effect on the excretion of estradiol.
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</p>
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<p>
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Some of the isoflavones, lignins, and other phytoestrogens are said to prevent bowel cancer, but some of
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them, e.g., lignin, appear to sometimes increase its likelihood.
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</p>
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<p>
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The phytoestrogens appear to pose a risk to organs besides the breast and uterus, for example the liver,
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colon, and pancreas, which isn't surprising, since estrogen is known to be carcinogenic for every tissue.
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And carcinogenesis, like precancerous changes, mutations, and reduced repair of DNA, is probably just an
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incidental process in the more general toxic effect of acceleration of aging.
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</p>
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<p><strong><h3>REFERENCES & ABSTRACTS</h3></strong></p>
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<p>
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<strong>"Stimulatory influence of soy protein isolate on breast secretion in pre- and postmenopausal
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women,"</strong> Petrakis NL; Barnes S; King EB; Lowenstein J; Wiencke J; Lee MM; Miike R; Kirk M;
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Coward L Department of Epidemiology and Biostatistics, University of California, San Francisco 94143-0560,
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USA. Cancer Epidemiol Biomarkers Prev, 1996 Oct, 5:10, 785-94 "Soy foods have been reported to have
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protective effects against premenopausal breast cancer in Asian women. No studies have been reported on
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potential physiological effects of dietary soy consumption on breast gland function. We evaluated the
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influence of the long-term ingestion of a commercial soy protein isolate on breast secretory activity. We
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hypothesized that the features of nipple aspirate fluid (NAF) of non-Asian women would be altered so as to
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resemble those previously found in Asian women. At monthly intervals for 1 year, 24 normal pre- and
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postmenopausal white women, ages 30 to 58, underwent nipple aspiration of breast fluid and gave blood and
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24-h urine samples for biochemical studies. No soy was administered in months 1-3 and 10-12. Between months
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4-9 the women ingested daily 38 g of soy protein isolate containing 38 mg of genistein. NAF volume, <strong
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>gross cystic disease fluid protein (GCDFP-15) concentration</strong>, and NAF cytology were used as
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biomarkers of possible effects of soy protein isolate on the breast. In addition, plasma concentrations of
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estradiol, progesterone, sex hormone binding globulin, prolactin, cholesterol, high density
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lipoprotein-cholesterol, and triglycerides were measured. Compliance was assessed by measurements of
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genistein and daidzein and their metabolites in 24-h urine samples. Excellent compliance with the study
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protocol was obtained. Compared with NAF volumes obtained in months 1-3, <strong>a 2-6-fold increase in NAF
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volume ensued during months 4-9 in all premenopausal women.</strong> A minimal increase or no response
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was found in postmenopausal women. No changes were found in plasma prolactin, sex hormone binding globulin,
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cholesterol, high density lipoprotein cholesterol, and triglyceride concentrations. Compared with
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concentrations found in months 1-3 (no soy), <strong>plasma estradiol concentrations were elevated
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erratically throughout
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</strong>
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a "composite" menstrual cycle during the months of soy consumption. No significant changes were seen in
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plasma progesterone concentrations. No significant changes were found in plasma estrogen levels in
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postmenopausal women. A moderate decrease occurred in the mean concentration of GCDFP-15 in NAF in
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premenopausal women<u> during the months of soy ingestion. </u>
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<strong><u>Of potential concern was the cytological detection of epithelial hyperplasia in 7 of 24 women
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(29.2%) during the months they were consuming soy protein isolate. The findings did not support our
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a priori hypothesis. Instead, this pilot study indicates that prolonged consumption of soy protein
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isolate has a stimulatory effect on the premenopausal female breast, characterized by increased
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secretion of breast fluid, the appearance of hyperplastic epithelial cells,</u> and elevated levels
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of plasma estradiol.
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</strong>These findings are suggestive of an estrogenic stimulus from the isoflavones genistein and daidzein
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contained in soy protein isolate.
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</p>
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<p>
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J Clin Endocrinol Metab 1995 May;80(5):1685-1690 <strong>Dietary intervention study to assess estrogenicity
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of dietary soy among postmenopausal women.</strong> Baird DD, Umbach DM, Lansdell L, Hughes CL, Setchell
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KD, Weinberg CR, Haney AF, Wilcox AJ, Mclachlan JA. National Institute of Environmental Health Sciences,
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Research Triangle Park, North Carolina 27709, USA. We tested the hypothesis that postmenopausal women on a
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soy-supplemented diet show estrogenic responses. Ninety-seven postmenopausal women were randomized to either
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a group <strong>that was provided with soy foods for 4 weeks or a control group that was instructed to eat
|
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as usual.</strong> Changes in urinary isoflavone concentrations served as a measure of compliance and
|
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phytoestrogen dose. Changes in serum FSH, LH, sex hormone binding globulin, and vaginal cytology were
|
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measured to assess estrogenic response. <strong>The percentage of vaginal superficial cells (indicative of
|
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estrogenicity) increased for 19% of those eating the diet compared with 8% of controls</strong>
|
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<hr />
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</p>
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<p>
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Oncol Rep 1998 May-Jun;5(3):609-16 <strong>
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"Maternal genistein exposure mimics the effects of estrogen on mammary gland development in female mouse
|
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offspring."</strong> Hilakivi-Clarke L, Cho E, Clarke R Lombardi Cancer Center, Research Bldg., Room
|
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W405, Georgetown University, 3970 Reservoir Road, NW, Washington, DC, 20007-2197, USA. <strong>Human and
|
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animal data indicate that a high maternal estrogen exposure during pregnancy increases breast cancer
|
||||
risk among daughters. This may reflect an increase in the epithelial structures</strong> that are the
|
||||
sites for malignant transformation, i.e., terminal end buds (TEBs), and a reduction in epithelial
|
||||
differentiation in the mammary gland. Some <strong>phytoestrogens, such as genistein which is a major
|
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component in soy-based foods, and zearalenone, a mycotoxin found in agricultural products, have
|
||||
estrogenic effects on the reproductive system, breast and brain.
|
||||
</strong>The present study examined whether in utero exposure to genistein or zearalenone influences mammary
|
||||
gland development. Pregnant mice were injected daily with i) 20 ng estradiol (E2); ii) 20 microg genistein;
|
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iii) 2 microg zearalenone; iv) 2 microg tamoxifen (TAM), a partial estrogen receptor agonist; or v)
|
||||
oil-vehicle between days 15 and 20 of gestation. E2, <strong>genistein, zearalenone, and tamoxifen all
|
||||
increased the density of TEBs in the mammary glands. Genistein reduced, and zearalenone increased,
|
||||
epithelial differentiation.</strong> Zearalenone also increased epithelial density, when compared with
|
||||
the vehicle-controls. None of the treatments had permanent effects on circulating E2 levels. <strong>
|
||||
Maternal exposure to E2 accelerated body weight gain, physical maturation (eyelid opening), and puberty
|
||||
onset (vaginal opening) in the female offspring. Genistein and tamoxifen had similar effects on puberty
|
||||
onset than E2.</strong> Zearalenone caused persistent cornification of the estrus smears. These findings
|
||||
indicate that <strong>maternal exposure to physiological doses of genistein mimics the effects of E2 on the
|
||||
mammary gland and reproductive systems in the offspring. Thus, our results suggest that genistein acts
|
||||
as an estrogen in utero, and may increase the incidence of mammary tumors if given through a pregnant
|
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mother.
|
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</strong>
|
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|
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The estrogenic effects of zearalenone on the mammary gland, in contrast, are probably counteracted by the
|
||||
permanent changes in estrus cycling.
|
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</p>
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<p>
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<strong>[The effects on the thyroid gland of soybeans administered experimentally in healthy
|
||||
subjects]</strong>
|
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Ishizuki Y; Hirooka Y; Murata Y; Togashi K Nippon Naibunpi Gakkai Zasshi, 1991 May 20, 67:5, 622-9 To
|
||||
elucidate whether soybeans would suppress the thyroid function in healthy adults, we selected 37 subjects
|
||||
who had never had goiters or serum antithyroid antibodies. They were given 30g of soybeans everyday and were
|
||||
divided into 3 groups subject to age and duration of soybean administration. In group 1, 20 subjects were
|
||||
given soybeans for 1 month. Groups 2 and 3 were composed of 7 younger subjects (mean 29 y.o.) and 10 elder
|
||||
subjects (mean 61 y.o.) respectively, and the subjects belonging to these groups received soybeans for 3
|
||||
months. The Wilcoxon-test and t-test were used in the statistical analyses. In all groups, the various
|
||||
parameters of serum thyroid hormones remained unchanged by taking soybeans, however TSH levels rose
|
||||
significantly although they stayed within normal ranges. The TSH response after TRH stimulation in group 3
|
||||
revealed a more significant increase than that in group 2, although inorganic iodide levels were lowered
|
||||
during the administration of the soybeans. We have not obtained any significant correlation between serum
|
||||
inorganic iodide and TSH. Hypometabolic symptoms (malaise, constipation, sleepiness) and goiters appeared in
|
||||
half the subjects in groups 2 and 3 after taking soybeans for 3 months, but they disappeared 1 month after
|
||||
the cessation of soybean ingestion. These findings suggested that excessive soybean ingestion for a certain
|
||||
duration might suppress thyroid function and cause goiters in healthy people, especially elderly subjects.
|
||||
</p>
|
||||
<p>
|
||||
Exp Clin Endocrinol Diabetes 1996;104 Suppl 4:41-5 <strong>Iodolactones and iodoaldehydes--mediators of
|
||||
iodine in thyroid autoregulation.</strong> Dugrillon A Central Clinical Laboratory, University of
|
||||
Heidelberg, Germany. "Within the last decades multiple iodolipid-classes have been identified in thyroid
|
||||
tissue. For a long time they have been supposed to be involved in thyroid autoregulation, but for the time
|
||||
being no specific compounds could be isolated. A new approach was stimulated by the finding that <strong
|
||||
>thyroid cells were able to iodinate polyunsaturated fatty acids</strong> to form iodolactones and by the
|
||||
identification of alpha-iodohexadecanal (alpha-IHDA) as the major compound of an iodolipid fraction."
|
||||
</p>
|
||||
|
||||
<p>
|
||||
<strong>Plasma free fatty acids, inhibitor of extrathyroidal conversion of T4 to T3 and thyroid hormone
|
||||
binding inhibitor in patients with various nonthyroidal illnesses.</strong>
|
||||
Suzuki Y; Nanno M; Gemma R; Yoshimi T Endocrinol Jpn, 1992 Oct, 39:5, 445-53.
|
||||
</p>
|
||||
<p>
|
||||
<strong>[Endemic goiter in Austria. Is iodine deficiency the primary cause of goiter?]</strong>
|
||||
Grubeck-Loebenstein B; Kletter K; Kiss A; Vierhapper H; Waldh"usl W Schweiz Med Wochenschr, 1982 Oct 30,
|
||||
112:44, 1526-30 <strong>
|
||||
In spite of government-regulated iodide admixture to table salt, the incidence of goiter is still high
|
||||
in Austria.</strong>
|
||||
Iodine excretion and thyroid function were therefore investigated in 80 patients suffering from ordinary
|
||||
goiter in whom thyroid size and resulting symptoms had increased lately. 25 euthyroid non-goitrous subjects
|
||||
served as controls. 48% of the goitrous patients investigated presented with iodine excretion of less than
|
||||
70 micrograms/24 h, suggesting an insufficient iodine supply. Thyroid I131 uptake, basal and TRH-stimulated
|
||||
plasma TSH concentrations, and serum T3 levels were higher, whereas serum T4 levels were lower in these
|
||||
patients than in goitrous patients with higher iodine excretion and non-goitrous controls. Iodine deficiency
|
||||
thus appears to be of pathogenetic relevance in about half of the goitrous Austrian population. <strong
|
||||
>Other factors enhancing goiter development seem to assume particular importance in goitrous patients with a
|
||||
sufficient iodine supply.</strong>
|
||||
</p>
|
||||
<p>
|
||||
<strong>Biochemical and molecular changes at the cellular level in response to exposure to environmental
|
||||
estrogen-like chemicals.</strong> Roy D; Palangat M; Chen CW; Thomas RD; Colerangle J; Atkinson A; Yan
|
||||
ZJ Environmental Toxicology Program, University of Alabama, Birmingham 35294, USA. J Toxicol Environ Health,
|
||||
1997 Jan, 50:1, 1-29. Estrogen-like chemicals are unique compared to nonestrogenic xenobiotics, because in
|
||||
addition to their chemical properties, the estrogenic property of these compounds allows them to act like
|
||||
sex hormones. <strong>
|
||||
Whether weak or strong, the estrogenic response of a chemical, if not overcome, will add extra
|
||||
estrogenic burden to the system. At elevated doses, natural estrogens and environmental estrogen-like
|
||||
chemicals are known to produce adverse effects. The source of extra or elevated concentration of
|
||||
estrogen could be either endogenous or exogenous.</strong> The potential of exposure for humans and
|
||||
animals to environmental estrogen-like chemicals is high. Only a limited number of estrogen-like compounds,
|
||||
such as diethylstilbestrol (DES), bisphenol A, nonylphenol, polychlorinated biphenyls (PCBs), and
|
||||
dichlorodiphenyltrichloroethane (DDT), have been used to assess the biochemical and molecular changes at the
|
||||
cellular level. Among them, DES is the most extensively studied estrogen-like chemical, and therefore this
|
||||
article is focused mainly on DES-related observations. In addition to estrogenic effects, environmental
|
||||
estrogen-like chemicals <strong>produce multiple and multitype genetic and/or nongenetic hits.</strong>
|
||||
Exposure of Syrian hamsters to stilbene estrogen (DES) produces several changes in the nuclei of target
|
||||
organ for carcinogenesis (kidney): (1) Products of nuclear redox reactions of DES modify transcription
|
||||
regulating proteins and DNA; (2) transcription is inhibited; (3) tyrosine phosphorylation of nuclear
|
||||
proteins, including RNA polymerase II, p53, and nuclear insulin-like growth factor-1 receptor, is altered;
|
||||
and (4<strong>) DNA repair gene DNA polymerase beta transcripts are decreased and mutated.</strong> Exposure
|
||||
of Noble rats to DES also produces several changes in the mammary gland: proliferative activity is
|
||||
drastically altered; the cell cycle of mammary epithelial cells is perturbed; telomeric length is
|
||||
attenuated; etc. It appears that some other estrogenic compounds, such as bisphenol A and nonylphenol, may
|
||||
also follow a similar pattern of effects to DES, because we have recently shown that these compounds <strong
|
||||
>alter cell cycle kinetics, produce telomeric associations, and produce chromosomal aberrations.
|
||||
</strong>
|
||||
|
||||
Like DES, bisphenol A after metabolic activation is capable of binding to DNA. However, it should be noted
|
||||
that a particular or multitype hit(s) will depend upon the nature of the environmental estrogen-like
|
||||
chemical. The role of individual attack leading to a particular change is not clear at this stage.
|
||||
Consequences of these multitypes of attack on the nuclei of cells could be (1) nuclear toxicity/cell death;
|
||||
(2) repair of all the hits and then acting as normal cells; or (3) sustaining most of the hits and acting as
|
||||
unstable cells. Proliferation of the last type of cell is expected to result in transformed cells.
|
||||
</p>
|
||||
<p>
|
||||
<strong>Potential adverse effects of phytoestrogens.</strong> Whitten PL; Lewis C; Russell E; Naftolin F
|
||||
Department of Anthropology, Emory University, Atlanta, GA 30322. J Nutr, 1995 Mar, 125:3 Suppl, 771S-776S
|
||||
Evaluation of the potential benefits and risks offered by naturally occurring plant estrogens requires
|
||||
investigation of their potency and sites of action when consumed at natural dietary concentrations. Our
|
||||
investigations have examined the effects of a range of natural dietary concentrations of the most potent
|
||||
plant isoflavonoid, coumestrol, using a rat model and a variety of estrogen-dependent tissues and endpoints.
|
||||
Treatments of immature<strong>
|
||||
females demonstrated agonistic action in the reproductive tract, brain, and pituitary at natural dietary
|
||||
concentrations. Experiments designed to test for estrogen antagonism demonstrated that coumestrol did
|
||||
not conform to the picture of a classic antiestrogen.
|
||||
</strong>
|
||||
However, coumestrol did suppress estrous cycles in adult females. Developmental actions were examined by
|
||||
neonatal exposure of pups through milk of rat dams fed a coumestrol, control, or commercial soy-based diet
|
||||
during the critical period of the first 10 postnatal days or throughout the 21 days of lactation. The 10-day
|
||||
treatment did not significantly alter adult estrous cyclicity, but the 21-day treatment produced in a
|
||||
<strong>persistent estrus state in coumestrol-treated females by 132 days of age.</strong> In contrast, the
|
||||
10-day coumestrol treatments produced <strong>significant deficits in the sexual behavior of male
|
||||
offspring.</strong> These findings illustrate the broad range of actions of these natural estrogens and
|
||||
the variability in potency across endpoints. This variability argues for the importance of fully
|
||||
characterizing each phytoestrogen in terms of its sites of action, balance of agonistic and antagonistic
|
||||
properties, natural potency, and short-term and long-term effects.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Am J Obstet Gynecol 1987 Aug;157(2):312-317 <strong>
|
||||
Age-related changes in the female hormonal environment during reproductive life.</strong> Musey VC,
|
||||
Collins DC, Musey PI, Martino-Saltzman D, Preedy JR. Previous studies have indicated that serum levels of
|
||||
follicle-stimulating hormone rise with age during the female reproductive life, but the effect on other
|
||||
hormones is not clear. We studied the effects of age, independent of pregnancy, by comparing serum hormone
|
||||
levels in two groups of nulliparous,<strong>
|
||||
premenopausal women aged 18 to 23 and 29 to 40 years. We found that increased age during reproductive
|
||||
life is accompanied by a significant rise in both basal and stimulated serum follicle-stimulating
|
||||
hormone levels. This was accompanied by an increase in the serum level of estradiol-17 beta and the
|
||||
urine levels of estradiol-17 beta and 17 beta-estradiol-17-glucosiduronate.</strong> The serum level of
|
||||
estrone sulfate decreased with age. Serum and urine levels of other estrogens were unchanged. The basal and
|
||||
stimulated levels of luteinizing hormone were also unchanged. There was a significant decrease in basal and
|
||||
stimulated serum prolactin levels. Serum levels of dehydroepiandrosterone and dehydroepiandrosterone sulfate
|
||||
decreased with age, but serum testosterone was unchanged. It is concluded that significant age-related
|
||||
changes in the female hormonal environment occur during the reproductive years.
|
||||
</p>
|
||||
<p>
|
||||
Rodriguez, P; Fernandez-Galaz, C; Tejero, A. <strong>Controlled neonatal exposure to estrogens: A suitable
|
||||
tool for reproductive aging studies in the female rat.</strong>
|
||||
Biology of Reproduction, v.49, n.2, (1993): 387-392. The present study was designed to determine whether the
|
||||
modification of exposure time to large doses of estrogens provided a reliable model for early changes in
|
||||
reproductive aging. Silastic implants containing estradiol benzoate (EB) in solution were placed into
|
||||
5-day-old female Wistar rats and removed 1 day (Ei1 group) or 5 days (Ei5) later. In addition, 100 mu-g EB
|
||||
dissolved in 100 mu-l corn oil was administered s.c. to another group (EI). Control rats received either
|
||||
vehicle implants or 100 mu-l corn oil. Premature occurrence of vaginal opening was observed in all three
|
||||
estrogenized groups independently of EB exposure. However, females bearing implants for 24 h had first
|
||||
estrus at the same age as their controls and cycled regularly, and neither histological nor gonadal
|
||||
alterations could be observed at 75 days.. Interestingly, they failed to cycle regularly at 5 mo whereas
|
||||
controls continued to cycle. On the other hand, the increase of EB exposure (Ei5, EI) resulted in a gradual
|
||||
and significant delay in the onset of first estrus and in a high number of estrous phases, as frequently
|
||||
observed during reproductive decline. At 75 days, the ovaries of these last two groups showed a reduced
|
||||
number of corpora lutea and an increased number of large follicles. According to this histological pattern,
|
||||
ovarian weight and <strong>progesterone (P) content gradually decreased whereas both groups showed higher
|
||||
estradiol (E-2) content</strong> than controls. This resulted in <strong>a higher E-2:P ratio,
|
||||
comparable to that observed in normal aging rats.</strong> The results allow us to conclude that the
|
||||
exposure time to large doses of estrogens is critical to the gradual enhancement of reproductive decline.
|
||||
Furthermore, exposures as brief as 24 h led to a potential early model for aging studies that will be useful
|
||||
to verify whether neuroendocrine changes precede gonadal impairment.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Cancer Lett 1992 Oct 30;67(1):55-59 <strong>
|
||||
Evidence of hypothalamic involvement in the mechanism of transplacental carcinogenesis by
|
||||
diethylstilbestrol.</strong> Smith DA, Walker BE Anatomy Department, Michigan State University, East
|
||||
Lansing 48824-1316. Disruption of hypothalamic sex differentiation in the fetus is one hypothesis to explain
|
||||
female reproductive system anomalies and cancer arising from prenatal exposure to diethylstilbestrol (DES).
|
||||
To further test this hypothesis, breeding performance and behavior were monitored in a colony of mice
|
||||
exposed prenatally to DES, using a schedule previously shown to produce anomalies and cancer of the female
|
||||
reproductive system. <strong>
|
||||
Fertility decreased with age more rapidly in DES-exposed females than in control females.</strong>
|
||||
DES-exposed females were less accepting of the male than control females. These observations support the
|
||||
hypothesis of abnormal hypothalamic sex differentiation as a basic mechanism in DES transplacental
|
||||
carcinogenesis.
|
||||
</p>
|
||||
<p>
|
||||
Int J Cancer 1980 Aug;26(2):241-6 <strong>
|
||||
The influence of the lipid composition of the feed given to mice on the immunocompetence and tumour
|
||||
resistance of the progeny.</strong>
|
||||
Boeryd B, Hallgren B. In inbred CBA mice, the immunocompetence of adult progeny from breeding pairs fed
|
||||
three different diets was compared.<strong>
|
||||
Substitution of soy oil for animal fat in the feed of the mice during gestation or lactation
|
||||
significantly decreased the PFC response to SRBC in the adult offspring.</strong> Addition of
|
||||
2-methoxy-substituted glycerol ethers to the feed of mothers deprived of animal fat during lactation partly
|
||||
restored the PFC response of the male offspring. In the adult mice fed differently pre- and perinatally the
|
||||
resistance to a transplanted syngeneic sarcoma was similar. The growth of offspring from mice fed the three
|
||||
diets was similar. In mice deprived of animal fat at weaning and for the following 21 days the immune
|
||||
reactivity to SRBC, tested about 3 months after stopping the diet, was not influenced. However, the
|
||||
resistance to a transplanted tumour in similarly fed mice was increased and this resistance was brought
|
||||
approximately to the control level by methoxy-substituted glycerol ethers.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Cancer Res 1987 Mar 1;47(5):1333-8. <strong>
|
||||
Effects of dietary fats and soybean protein on azaserine-induced pancreatic carcinogenesis and plasma
|
||||
cholecystokinin in the rat.</strong> Roebuck BD, Kaplita PV, Edwards BR, Praissman M<strong>
|
||||
Both dietary unsaturated fat and raw soybean products are known to enhance pancreatic carcinogenesis
|
||||
when fed during the postinitiation phase. A comparison of these two dietary components was made
|
||||
to</strong> evaluate the relative potency of each ingredient for enhancing pancreatic carcinogenesis and
|
||||
to determine if this enhancement was correlated with an increase in plasma cholecystokinin (CCK) levels.
|
||||
Male Wistar rats were initiated with a single dose of azaserine (30 mg/kg body weight) at 14 days of age.
|
||||
The rats were weaned to test diets formulated from purified ingredients. Dietary protein at 20% by weight
|
||||
was either casein or soy protein isolate (heat treated or raw).. Corn oil was the unsaturated fat of major
|
||||
interest and it was fed at either 5 or 20% by weight. Pancreases were quantitatively evaluated for
|
||||
carcinogen-induced lesions at 2- and 4-month postinitiation. In a second experiment designed to closely
|
||||
mimic the above experiment, rats were implanted with cannulae which allowed plasma to be repetitively
|
||||
sampled over a 2.5-week period during which the test diets were fed. Plasma was collected both prior to
|
||||
introduction of the test diets and afterwards. Plasma CCK was measured by a specific radioimmunoassay. Both
|
||||
the 20% corn oil diet and the raw soy protein isolate diet enhanced pancreatic carcinogenesis. The effects
|
||||
of the raw soy protein isolate on the growth of the carcinogen-induced lesions were significantly greater
|
||||
than the effects of the 20% corn oil diet. Plasma CCK values were not elevated in the rats fed the 20% corn
|
||||
oil diet, but they were significantly elevated in the rats fed the raw soy protein isolate. Heat-treated soy
|
||||
protein isolate neither enhanced carcinogenesis nor elevated the plasma CCK level. This<strong>
|
||||
study demonstrates that certain plant proteins enhance the growth of carcinogen-induced pancreatic foci
|
||||
and that this effect is considerably greater than the enhancement by high levels of dietary unsaturated
|
||||
fat. Furthermore, the enhancement by the raw soy protein isolate may be mediated by CCK; but this does
|
||||
not appear to be the mechanism by which the unsaturated fat, corn oil, enhances pancreatic
|
||||
carcinogenesis.</strong>
|
||||
</p>
|
||||
<p>
|
||||
J Biol Chem 1988 Mar 15;263(8):3639-3645 <strong>
|
||||
Dynamic pattern of estradiol binding to uterine receptors of the rat.</strong>
|
||||
<strong>
|
||||
Inhibition and stimulation by unsaturated fatty acids.</strong> Vallette G, Christeff N, Bogard C,
|
||||
Benassayag C, Nunez E
|
||||
</p>
|
||||
<p>
|
||||
J Biol Chem 1986 Feb 25;261(6):2954-2959 <strong>
|
||||
Modifications of the properties of human sex steroid-binding protein by nonesterified fatty
|
||||
acids.</strong> Martin ME, Vranckx R, Benassayag C, Nunez EA The effect of unsaturated and saturated
|
||||
nonesterified fatty acids (NEFAs) on the electrophoretic, immunological, and steroid-binding properties of
|
||||
human sex hormone-binding protein (SBP) were investigated. Tests were carried out on whole serum from
|
||||
pregnant women and on purified SBP using polyacrylamide gel electrophoresis, crossed immunoelectrophoresis
|
||||
with autoradiography, and equilibrium dialysis. All three methods showed that NEFAs influence the binding of
|
||||
sex steroids to SBP both in whole serum and with the purified protein. Saturated NEFAs caused a 1.5-2-fold
|
||||
increase in binding of<strong>
|
||||
dehydrotestosterone, testosterone, and estradiol to SBP, while unsaturated NEFAs, such as oleic (18:1)
|
||||
and docosahexaenoic (22:6) acids inhibited the binding of these steroids to SBP. Thus, unsaturated
|
||||
NEFAs</strong> in the concentration range 1-100 microM are more inhibitory for estradiol binding than
|
||||
for testosterone or dehydrotestosterone binding. In addition to these binding changes, polyacrylamide gel
|
||||
electrophoresis and immunoelectrophoretic studies revealed a shift in SBP from the slow-moving active native
|
||||
form to a fast-moving inactive one. There was also a reduction in the apparent SBP concentration by Laurell
|
||||
immunoelectrophoresis in the presence of unsaturated NEFA (5.5 nmol of NEFA/pmol of protein). These studies
|
||||
indicate that unsaturated NEFAs induce conformational changes in human SBP which are reflected in its
|
||||
electrophoretic, immunological, and steroid-binding properties. They suggest that the fatty acid content of
|
||||
the SBP environment may result in lower steroid hormone binding and thus increased free hormone levels.
|
||||
</p>
|
||||
<p>
|
||||
J Biol Chem 1986 Feb 25;261(6):2954-2959 <strong>
|
||||
Modifications of the properties of human sex steroid-binding protein by nonesterified fatty
|
||||
acids.</strong> Martin ME, Vranckx R, Benassayag C, Nunez EA The effect of unsaturated and saturated
|
||||
nonesterified fatty acids (NEFAs) on the electrophoretic, immunological, and steroid-binding properties of
|
||||
human sex hormone-binding protein (SBP) were investigated. Tests were carried out on whole serum from
|
||||
pregnant women and on purified SBP using polyacrylamide gel electrophoresis, crossed immunoelectrophoresis
|
||||
with autoradiography, and equilibrium dialysis. All three methods showed that NEFAs influence the binding of
|
||||
sex steroids to SBP both in whole serum and with the purified protein. Saturated NEFAs caused a 1.5-2-fold
|
||||
increase in binding of<strong>
|
||||
dehydrotestosterone, testosterone, and estradiol to SBP, while unsaturated NEFAs, such as oleic (18:1)
|
||||
and docosahexaenoic (22:6) acids inhibited the binding of these steroids to SBP.
|
||||
</strong>
|
||||
|
||||
Thus, unsaturated NEFAs in the concentration range 1-100 microM are more inhibitory for estradiol binding
|
||||
than for testosterone or dehydrotestosterone binding. In addition to these binding changes, polyacrylamide
|
||||
gel electrophoresis and immunoelectrophoretic studies revealed a shift in SBP from the slow-moving active
|
||||
native form to a fast-moving inactive one. There was also a reduction in the apparent SBP concentration by
|
||||
Laurell immunoelectrophoresis in the presence of unsaturated NEFA (5.5 nmol of NEFA/pmol of protein). These
|
||||
studies indicate that unsaturated NEFAs induce conformational changes in human SBP which are reflected in
|
||||
its electrophoretic, immunological, and steroid-binding properties. They suggest that the fatty acid content
|
||||
of the SBP environment may result in lower steroid hormone binding and <strong>
|
||||
thus increased free hormone levels.
|
||||
</strong>
|
||||
</p>
|
||||
<p>
|
||||
J Steroid Biochem 1986 Feb;24(2):657-659 <strong>
|
||||
Free fatty acids: a possible regulator of the available oestradiol fractions in plasma.</strong> Reed
|
||||
MJ, Beranek PA, Cheng RW, James VH Consumption of dietary fats has been linked to the high incidence of
|
||||
breast cancer found in Western women. In vitro studies we have carried out show that <strong>
|
||||
unsaturated free fatty acids can increase the biologically available oestradiol fractions in
|
||||
plasma.</strong> It is possible therefore that the increased risk for breast cancer associated with a
|
||||
diet high in fats may be related to an elevation in the biologically available oestradiol fractions in
|
||||
plasma.
|
||||
</p>
|
||||
<p>
|
||||
Endocrinology 1986 Jan;118(1):1-7 <strong>
|
||||
Potentiation of estradiol binding to human tissue proteins by unsaturated nonesterified fatty
|
||||
acids.</strong> Benassayag C, Vallette G, Hassid J, Raymond JP, Nunez EA Nonesterified fatty acids
|
||||
(NEFAs) have been recently shown in the rat to be involved in steroid hormone expression, having effects on
|
||||
plasma transport and <strong>intracellular activity. </strong>
|
||||
|
||||
This study examines the influence of saturated and unsaturated NEFAs on estradiol (E2) binding to cytosol
|
||||
from human uterus, breast, and melanoma. Binding was analyzed after separation with dextran-coated charcoal
|
||||
or hydroxylapatite and by sucrose density gradient centrifugation. <strong>
|
||||
Unsaturated NEFAs induced a 2- to 10-fold increase (P less than 0.001) in E2 binding to cytosol
|
||||
</strong>from normal, fibromatous, and neoplastic uteri, while saturated NEFAs<strong>
|
||||
had a slight inhibitory effect</strong> (P less than 0.05). Similar effects were seen with cytosol from
|
||||
metastatic melanoma lymph nodes and neoplastic breast tissues. By contrast, unsaturated NEFAs did not
|
||||
increase E2 binding to serum from these patients. Density gradient centrifugation indicated that the
|
||||
increased binding was associated with the proteins present in the 2- to 4 S region. Analysis of E2
|
||||
metabolites in the presence of unsaturated NEFAs showed the formation of water-soluble derivatives. Seventy
|
||||
percent of these E2 derivatives were trichloracetic acid precipitable, suggesting a covalent link between
|
||||
the steroid and a protein. The existence of such water-soluble metabolites could be erroneously interpreted
|
||||
as a true binding to soluble cytoplasmic receptors.
|
||||
</p>
|
||||
<p>
|
||||
Ann N Y Acad Sci 1988;538:257-264 <strong>
|
||||
Possible relevance of steroid availability and breast cancer.</strong> Bruning PF, Bonfrer JM
|
||||
Netherlands Cancer Institute (Antoni van Leeuwenhoekhuis), Amsterdam. "The as yet circumstantial evidence
|
||||
for a central role of estrogens in the promotion of human breast cancer is supported by many data. However,
|
||||
it has not been possible to identify breast cancer patients or women at risk by abnormally elevated estrogen
|
||||
levels in plasma. <strong>The concept of available, i.e., non-SHBG bound sex steroid seems to offer a better
|
||||
understanding than total serum steroid levels do. We demonstrated that sex steroid protein binding is
|
||||
decreased by free fatty acids."</strong>
|
||||
</p>
|
||||
<p>
|
||||
J Surg Oncol 1993 Feb;52(2):77-82. <strong>
|
||||
The effect of the fiber components cellulose and lignin on experimental colon neoplasia.</strong> Sloan
|
||||
DA, Fleiszer DM, Richards GK, Murray D, Brown RA Department of Surgery, University of Kentucky College of
|
||||
Medicine, Lexington. Sixty Sprague-Dawley rats were pair-fed one of three nutritionally identical diets. One
|
||||
diet contained "low-fiber" (3.8% crude fiber); the others contained "high fiber" (28.7% crude fiber)
|
||||
composed of either cellulose or lignin. Although both "high fiber" diets had similar stool bulking effects,
|
||||
<strong> only the cellulose diet</strong>
|
||||
was associated with a reduction in 1,2-dimethylhydrazine (DMH)-induced colon neoplasms. The cellulose diet
|
||||
was also associated with distinct changes in the gut bacterial profile and with a lowered serum cholesterol.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Nutr Cancer 1984;6(2):77-85 <strong>
|
||||
Enhancement of 1,2-dimethylhydrazine-induced large bowel tumorigenesis in Balb/c mice by corn, soybean,
|
||||
and wheat brans.</strong> Clapp NK, Henke MA, London JF, Shock TL This study was designed to determine
|
||||
the effects of four well-characterized dietary brans on large bowel tumorigenesis induced in mice with
|
||||
1,2-dimethylhydrazine (DMH). Eight-week-old barrier-derived male Balb/c mice were fed a semisynthetic diet
|
||||
with 20% bran added (either corn, soybean, soft winter wheat, or hard spring wheat) or a no-fiber-added
|
||||
control diet. Half of each group was given DMH (20 mg/kg body weight/week, subcutaneously for 10 weeks)
|
||||
beginning at 11 weeks of age. Surviving mice were killed 40 weeks after the first DMH injection. Tumors were
|
||||
not found in mice not subjected to DMH. In DMH-treated mice, tumors were found almost exclusively in the
|
||||
distal colon. Tumor incidences were as follows: <strong>controls, 11%; soybean group, 44%; soft winter wheat
|
||||
group, 48%; hard spring wheat group, 58%; and corn group, 72%.
|
||||
</strong>
|
||||
Tumors per tumor-bearing mouse ranged from 1.4 to 1.6, except in the corn group, which had 2.1. <strong>A
|
||||
positive correlation was found between percentage of neutral detergent fiber in the brans and tumor
|
||||
incidences</strong>
|
||||
but not between the individual components of cellulose, hemicellulose, or lignin. The <strong>enhancement of
|
||||
DMH-induced large bowel tumorigenesis by all four bran types may reflect a species and/or mouse strain
|
||||
effect that is bran-source related. These data emphasize the importance of using well-defined bran in
|
||||
all "fiber" studies.
|
||||
</strong>
|
||||
</p>
|
||||
<p>
|
||||
Prev Med 1987 Jul;16(4):540-4 <strong>
|
||||
Fiber, stool bulk, and bile acid output: implications for colon cancer risk.</strong> McPherson-Kay R
|
||||
Dietary fiber has direct effects on stool bulk and bile acid output that may be of relevance in the etiology
|
||||
of colon cancer. Most types of fiber increase the total volume of stool and reduce the concentration of
|
||||
specific substances, including bile acids, that are in contact with the bowel wall. However, fibers differ
|
||||
in their effect on stool bulk, with wheat fiber being a more effective stool bulking agent than fruit and
|
||||
vegetable fibers. In addition, the extent to which a specific fiber reduces bile acid concentration will be
|
||||
modified by its concomitant effects on total fecal sterol excretion. Whereas wheat bran reduces fecal bile
|
||||
acid concentration, <strong>pectin, lignin, and oat bran do not. These three fibers significantly increase
|
||||
total bile acid output. Bile acids act as promoters of colonic tumors in mutagenesis assay systems and
|
||||
in various animal models.</strong> Human epidemiological studies show a relationship between various
|
||||
dietary variables, including fat and fiber intake, fecal concentration of bile acids, and colon cancer risk.
|
||||
</p>
|
||||
<p>
|
||||
Eur J Gastroenterol Hepatol 1998 Jan;10(1):33-9 <strong>Intestinal absorption of oestrogen: the effect of
|
||||
altering transit-time.</strong> Lewis SJ, Oakey RE, Heaton KW University Department of Medicine, Bristol
|
||||
Royal Infirmary, UK. OBJECTIVE: The mechanism by which a high fibre diet may reduce serum oestrogens is
|
||||
unknown. We hypothesized that time is a rate-limiting factor in oestrogen absorption from the colon so that
|
||||
changes in colonic transit-rate affect the proportion of oestrogen that is deconjugated and/or absorbed.
|
||||
AIM: To determine if alteration of intestinal transit rate would influence the absorption of an oral dose of
|
||||
oestradiol glucuronide. PARTICIPANTS: Twenty healthy postmenopausal women recruited by advertisement.
|
||||
SETTING: Department of Medicine, Bristol Royal Infirmary. METHODS: Volunteers consumed, in turn, wheat bran,
|
||||
senna, loperamide and bran shaped plastic flakes, each for 10 days with a minimum 2 week washout period
|
||||
between study periods, dietary intake being unchanged. Before and in the last 4 days of each intervention
|
||||
whole-gut transit-time, defecation frequency, stool form, stool beta-glucuronidase activity, stool pH and
|
||||
the absorption of a 1.5 mg dose of oestradiol glucuronide were measured. RESULTS: Wheat bran, senna and
|
||||
plastic flakes led to the intended reduction in whole-gut transit-time, increase in defecatory frequency and
|
||||
increase in stool form score. Loperamide caused the opposite effect. <strong>The length of time the absorbed
|
||||
oestrogen was detectable in the serum fell with wheat bran and senna, although this was only significant
|
||||
for oestradiol.</strong>
|
||||
Oestrone, but not oestradiol, was detectable for a longer time with loperamide. Plastic flakes had no effect
|
||||
on either oestrogen. Areas under the curve did not change significantly but tended to fall with the three
|
||||
transit-accelerating agents and to rise with loperamide. CONCLUSION: Our data indicate there is likely to be
|
||||
an effect of intestinal transit on the absorption of oestrogens but more refined techniques are needed to
|
||||
characterize this properly.
|
||||
</p>
|
||||
<p>
|
||||
Br J Cancer 1997;76(3):395-400. <strong>
|
||||
Lower serum oestrogen concentrations associated with faster intestinal transit.</strong> Lewis SJ,
|
||||
Heaton KW, Oakey RE, McGarrigle HH University Department of Medicine, Bristol Royal Infirmary, UK. Increased
|
||||
fibre intake has been shown to reduce serum oestrogen concentrations. We hypothesized that fibre exerts this
|
||||
effect by decreasing the time available for reabsorption of oestrogens in the colon. We tested this in
|
||||
volunteers by measuring changes in serum oestrogen levels in response to manipulation of intestinal transit
|
||||
times with senna and loperamide, then comparing the results with changes caused by wheat bran. Forty healthy
|
||||
premenopausal volunteers were placed at random into one of three groups. The first group took senna for two
|
||||
menstrual cycles then, after a washout period, took wheat bran, again for two menstrual cycles. The second
|
||||
group did the reverse. The third group took loperamide for two menstrual cycles. At the beginning and end of
|
||||
each intervention a 4-day dietary record was kept and whole-gut transit time was measured; stools were taken
|
||||
for measurement of pH and beta-glucuronidase activity and blood for measurement of oestrone and oestradiol
|
||||
and their non-protein-bound fractions and of oestrone sulphate. <strong>
|
||||
Senna and loperamide caused the intended alterations in intestinal transit, whereas on wheat bran
|
||||
supplements there was a trend towards faster transit. Serum oestrone sulphate fell with wheat bran (mean
|
||||
intake 19.8 g day(-1)) and with senna; total- and non-protein-bound oestrone fell with senna.</strong>
|
||||
No significant changes in serum oestrogens were seen with loperamide. No significant changes were seen in
|
||||
faecal beta-glucuronidase activity. Stool pH changed only with senna, in which case it fell. In conclusion,
|
||||
speeding up intestinal transit can lower serum oestrogen concentrations.
|
||||
</p>
|
||||
<p>
|
||||
J Steroid Biochem Mol Biol 1991 Aug;39(2):193-202 <strong>Influence of wheat bran on NMU-induced mammary
|
||||
tumor development, plasma estrogen levels and estrogen excretion in female rats.</strong> Arts CJ, de
|
||||
Bie AT, van den Berg H, van 't Veer P, Bunnik GS, Thijssen JH TNO Toxicology and Nutrition Institute, The
|
||||
Netherlands. In our animal experiments the hypothesis was tested that a high-fiber (HF) diet reduces tumor
|
||||
promotion<strong>
|
||||
by interruption of the enterohepatic circulation resulting in lowered estrogen exposure of the
|
||||
estrogen-sensitive tissue.
|
||||
</strong>
|
||||
|
||||
In the first experiment the development of N-nitrosomethylurea (NMU) induced mammary tumors was
|
||||
investigated. One group of rats (HF) was fed a HF diet (11% fiber, based on wheat bran), the other group
|
||||
(LF) fed a low-fiber diet (0.5% fiber, based on white wheat flour). Tumor incidence (90 and 80%,
|
||||
respectively) and latency (121 and 128 days, respectively) were similar in the HF and LF groups. Compared to
|
||||
the LF group, HF rats had lower tumor weights (0.16 vs 0.55 g; P less than 0.01) and a slightly lower tumor
|
||||
multiplicity (1.8 vs 2.8 tumors per tumor-bearing rat). These differences were reduced after adjustment for
|
||||
body weight. In a second experiment rats, not treated with the carcinogen, were kept on the same HF and LF
|
||||
diets. From these rats 24-h urine and feces and orbital blood samples were<strong>
|
||||
collected for analysis of (un)conjugated estrogens. The excretion of both free and conjugated estrogens
|
||||
in fecal samples was about 3-fold higher in HF rats than in LF rats. During the basal period of the
|
||||
cycle urinary excretion of estrone was lower in HF rats (mean 9.7 ng/day) than in LF rats (mean 13.0
|
||||
ng/day; P less than 0.05). It is concluded that wheat bran interrupts the enterohepatic circulation of
|
||||
estrogens, but plasma levels are not affected. Whether the development of mammary tumors is reduced by
|
||||
the introduction of specific components of wheat bran, or by a reduced body weight due to a lower
|
||||
(effective) energy intake remains to be determined.
|
||||
</strong>
|
||||
</p>
|
||||
<p>
|
||||
Nutr Cancer 1998;31(1):24-30 <strong>
|
||||
Dietary lignin, and insoluble fiber, enhance uterine cancer but did not influence mammary cancer induced
|
||||
by N-methyl-N-nitrosourea in rats.</strong>
|
||||
Birt DF, Markin RS, Blackwood D, Harvell DM, Shull JD, Pennington KL Eppley Institute for Research in Cancer
|
||||
and Allied Disease, University of Nebraska Medical Center, Omaha 69198, USA. Previous investigations
|
||||
suggested potential breast cancer-preventive properties of dietary fiber from cabbage. The purpose of the
|
||||
present investigation was to determine whether lignin, a component of cabbage fiber, would protect against
|
||||
mammary carcinogenesis by N-methyl-N-nitrosourea (MNU) in Sprague-Dawley rats. A six-week study was
|
||||
conducted using diets containing 0.5-5% dietary wood lignin (a readily available, purified source). These
|
||||
diets were well tolerated by the rats, and a carcinogenesis study using 5 mg MNU/100 g body wt i.v. at 50
|
||||
days of age was conducted, with the 2.5% lignin diet fed from 6 through 8 weeks of age followed by 5% lignin
|
||||
diet until 20 weeks after MNU. Dietary lignin and MNU treatment increased food consumption (p < 0.05),
|
||||
and body weight was slightly reduced at 10 and 20 weeks after MNU in the MNU-5% lignin diet group (p <
|
||||
0.05). Serum estradiol was not altered by dietary lignin or MNU treatment, but uterine weights were highest
|
||||
in the MNU-control diet group 4 and 12 weeks after MNU. Expression of creatine kinase B, an
|
||||
estrogen-responsive gene, was lower in the uteri of the MNU-lignin diet group than in other groups at 20
|
||||
weeks. Mammary carcinogenesis was not altered by dietary lignin.<strong>
|
||||
However, uterine endometrial adenocarcinoma was observed only in the MNU-lignin diet group (4
|
||||
carcinomas/40 effective rats) (p < 0.05).
|
||||
</strong>
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Ginecol Obstet Mex 1998 Mar;66:111-8 <strong>
|
||||
[Estrogens of vegetable origin].</strong> [Article in Spanish] Rubio Lotvin B Reproduccion y de
|
||||
Ginecologia y Obstetricia Facultad de Medicina, UNAM Depto. de Ginecologia y Obstetricia Hospital Americano,
|
||||
Britanico Cowdray. Mexico, D.F. In recent years, estrogens of vegetable origin have acquired some importance
|
||||
that justify the presentation of the available data. The compounds that have estrogenic effect when ingested
|
||||
as food through<strong>
|
||||
vegetables include isoflavones, lignines and lactones. The review comprises their chemical
|
||||
structure,</strong> metabolism and excretion as well as their effect on plasmatic levels of estrogens
|
||||
FSH, LH and SHBG as well as their activity over lipoproteins and, naturally, their action on menopause
|
||||
symptoms and breast cancer.
|
||||
</p>
|
||||
<p>
|
||||
Proc Soc Exp Biol Med 1995 Jan;208(1):6-12 <strong>Chemical studies of phytoestrogens and related compounds
|
||||
in dietary supplements: flax and chaparral.</strong> Obermeyer WR, Musser SM, Betz JM, Casey RE, Pohland
|
||||
AE, Page SW Division of Natural Products, Food and Drug Administration, Washington, District of Columbia
|
||||
20204. High-performance liquid chromatographic (HPLC) and mass spectrometric (MS) procedures were developed
|
||||
to determine lignans in flaxseed (Linum usitatissimum) and chaparral (Larrea tridentata).<strong>
|
||||
Flaxseed contains high levels of phytoestrogens. Chaparral has been associated with acute nonviral toxic
|
||||
hepatitis and contains lignans that are structurally similar to known estrogenic compounds.
|
||||
</strong>
|
||||
|
||||
Both flaxseed and chaparral products have been marketed as dietary supplements. A mild enzyme hydrolysis
|
||||
procedure to prevent the formation of artifacts in the isolation step was used in the determination of
|
||||
secoisolariciresinol in flaxseed products. HPLC with ultraviolet spectral (UV) or MS detection was used as
|
||||
the determinative steps. HPLC procedures with UV detection and mass spectrometry were developed to<strong>
|
||||
characterize the phenolic components, including lignans and flavonoids,</strong> of chaparral and to
|
||||
direct fractionation studies for the bioassays.
|
||||
</p>
|
||||
<p>
|
||||
Brain Res 1994 Jul 25;652(1):161-3 <strong>
|
||||
The 21-aminosteroid antioxidant, U74389F, prevents estradiol-induced depletion of hypothalamic
|
||||
beta-endorphin in adult female rats.</strong>
|
||||
Schipper HM, Desjardins GC, Beaudet A, Brawer JR Department of Anatomy and Cell Biology, Bloomfield Centre
|
||||
for Research in Aging, Jewish General Hospital, McGill University, Montreal, Que., Canada.<strong>
|
||||
A single intramuscular injection of 2 mg estradiol valerate (EV) results in neuronal degeneration
|
||||
</strong>and beta-endorphin depletion in the hypothalamic arcuate nucleus of adult female rats. We have
|
||||
hypothesized that peroxidase-positive astrocytes in this brain region oxidize estrogens and
|
||||
catecholestrogens to semiquinone radicals which mediate oxidative neuronal injury. In the present study,
|
||||
dietary administration of the potent antioxidant 21-aminosteroid, U-74389F, completely blocked EV-induced
|
||||
beta-endorphin depletion in the hypothalami of adult female rats. Neither EV nor 21-aminosteroid treatment
|
||||
had any effect on hypothalamic concentrations of neuropeptide Y and Met-enkephalin, <strong>confirming that
|
||||
the estradiol lesion is fairly selective for the beta-endorphin cell population.
|
||||
</strong>
|
||||
The present findings support the hypothesis that the toxic effect of estradiol on hypothalamic
|
||||
beta-endorphin neurons is mediated by free radicals.
|
||||
</p>
|
||||
<p>
|
||||
J Steroid Biochem Mol Biol 1998 Feb;64(3-4):207-15, <strong>"Effects of tea polyphenols and flavonoids on
|
||||
liver microsomal glucuronidation of estradiol and estrone."</strong>
|
||||
Zhu BT, Taneja N, Loder DP, Balentine DA, Conney AH "Administration of 0.5 or 1% lyophilized green tea (5 or
|
||||
10 mg tea solids per ml, respectively) as the sole source of drinking fluid to female Long-Evans rats for 18
|
||||
days stimulated liver microsomal glucuronidation of estrone, estradiol and 4-nitrophenol by 30-37%, 15-27%
|
||||
and 26-60%, respectively. Oral administration of 0.5% lyophilized green tea to female CD-1 mice for 18 days
|
||||
stimulated liver microsomal glucuronidation of estrone, estradiol and 4-nitrophenol by 33-37%, 12-22% and
|
||||
172-191%, respectively. The in vitro addition of a green tea polyphenol mixture, a black tea polyphenol
|
||||
mixture or (-)-epigallocatechin gallate inhibited rat liver microsomal glucuronidation of estrone and
|
||||
estradiol in a concentration-dependent manner and their IC50 values for inhibition of estrogen metabolism
|
||||
were approximately 12.5, 50 and 10 microg/ml, respectively. Enzyme kinetic analysis indicates that the
|
||||
inhibition of estrone glucuronidation by 10 microM (-)-epigallocatechin gallate was competitive while
|
||||
inhibition by 50 microM (-)-epigallocatechin gallate was noncompetitive. Similarly, several flavonoids
|
||||
(naringenin, hesperetin, kaempferol, quercetin, rutin, flavone, alpha-naphthoflavone and
|
||||
beta-naphthoflavone) also inhibited rat liver microsomal glucuronidation of estrone and estradiol to varying
|
||||
degrees. Naringenin and hesperetin displayed the strongest inhibitory effects (IC50 value of approximately
|
||||
25 microM). These two hydroxylated flavonoids had a competitive mechanism of enzyme inhibition for estrone
|
||||
glucuronidation at a 10 microM inhibitor concentration and a predominantly noncompetitive mechanism of
|
||||
inhibition at a 50 microM inhibitor concentration."
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Toxicology 1997 Sep 26;122(1-2):61-72, <strong>
|
||||
"Effects of co-administration of butylated hydroxytoluene, butylated hydroxyanisole and flavonoids on
|
||||
the activation of mutagens and drug-metabolizing enzymes in mice.</strong>" Sun B, Fukuhara M Effects of
|
||||
co-administration of food additives and naturally occurring food components were studied on the activation
|
||||
of mutagens. Male mice (ddY) were given diets containing butylated hydroxytoluene (BHT) or butylated
|
||||
hydroxyanisole (BHA) and flavone or flavanone (2,3-dihydroflavone) for two weeks and the ability of hepatic
|
||||
microsomes to activate aflatoxin B1, benzo[a]pyrene and N-nitrosodimethylamine was determined by the
|
||||
mutagenicity test. Co-administration of an antioxidant (0.1% BHT or 0.2% BHA in diet) and a flavonoid (0.1%
|
||||
flavone or 0.1% flavanone) <strong>resulted in additive effects on the activation of aflatoxin B1 and
|
||||
benzo[a]pyrene,</strong> while the activation of N-nitrosodimethylamine was not elevated significantly
|
||||
by the co-administration. To understand the mechanism for the additive effects, induction of specific
|
||||
isozymes of cytochrome P450 involved in the activation of the mutagens was studied. Co-administration of BHT
|
||||
(0.1%) and flavone (0.1%) increased markedly the levels of proteins and the activities of the enzymes
|
||||
related to the isozymes of CYP2A and CYP2B, while co-administration of BHA (0.2%) and flavanone (0.1%)
|
||||
elevated those related to CYP1A. Further, the activation of aflatoxin B1 and benzo[a]pyrene in hepatic
|
||||
microsomes was inhibited by the antibodies against these isozymes, which suggested that the enhanced
|
||||
activation of the mutagens by the co-administration might be mediated by the induction of these isozymes.
|
||||
</p>
|
||||
<p>
|
||||
Biochem Soc Trans 1977;5(5):1489-92. <strong>Frameshift mutagenicity of certain naturally occurring phenolic
|
||||
compounds in the 'Salmonella/microsome' test: activation of anthraquinone and flavonol glycosides by gut
|
||||
bacterial enzymes.</strong> Brown JP, Dietrich PS, Brown RJ
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Mutagenesis 1997 Sep;12(5):383-90 <strong>
|
||||
"Involvement of rat cytochrome 1A1 in the biotransformation of kaempferol to quercetin: relevance to the
|
||||
genotoxicity of kaempferol.</strong>" Silva ID, Rodrigues AS, Gaspar J, Maia R, Laires A, Rueff J.
|
||||
"Kaempferol is a flavonoid widely distributed in edible plants and has been shown to be genotoxic to V79
|
||||
cells in the absence of external metabolizing systems. The presence of an external metabolizing system, such
|
||||
as rat liver homogenates (S9 mix), leads to an increase in its genotoxicity, which is attributed to its
|
||||
biotransformation to <strong>the more genotoxic flavonoid quercetin</strong>, via the cytochrome P450 (CYP)
|
||||
mono-oxygenase system."
|
||||
</p>
|
||||
<p>
|
||||
Environ Health Perspect 1997 Apr;105 Suppl 3:633-6 <strong>Dietary estrogens stimulate human breast cells to
|
||||
enter the cell cycle.</strong> Dees C, Foster JS, Ahamed S, Wimalasena J.<strong>
|
||||
"Our findings are consistent with a conclusion that dietary estrogens at low concentrations do not act
|
||||
as antiestrogens, but act like DDT and estradiol to stimulate human breast cancer cells to enter the
|
||||
cell cycle."</strong>
|
||||
</p>
|
||||
|
||||
<p>
|
||||
© Ray Peat 2008. All Rights Reserved. www.RayPeat.com
|
||||
</p>
|
||||
</body>
|
||||
</html>
|
||||
Reference in New Issue
Block a user