They behave like female hormones, estrogens, or they - some of them block androgens, male hormones.

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Time was of the essence after scientists detected an increase in Mei Xiang's urinary estrogens on Tuesday.

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Researchers measured the levels of phyto-estrogens in the urine of 144 British women.

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Premarin differs from Prempro and Premphase in that it contains only estrogen, rather than a combination of estrogens and progesterone.

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Soy foods--such as milk, tofu, and edamame--are rich in naturally occurring estrogens (especially isoflavones) that can mimic the effects of estrogen in the female body.

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Tofu, miso and tempeh are also excellent sources of phyto-estrogens.

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"Isoflavones, the plant-derived estrogens found in soy, are very weak estrogens, so it is not surprising that they have not shown to be as effective...as hormone therapy, " says the lead author of the study, Silvina Levis, M.

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Because the most common types of breast cancer depend on estrogen to grow, experts once feared that soy isoflavones could stimulate the estrogen receptors in breast-cancer cells, even though the estrogens in soy are much weaker than those produced by the body.

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