 Hops have been used for centuries as a flavoring agent in beer, but over the years a recurring suggestion has been that hops, and therefore beer, may be estrogenic, thanks to a potent phytoestrogen in hops called 8-PN, also known as hoppian, might beer drinking affect our hormones. And now, even just the alcohol in beer can reduce testosterone levels in men, so when beer was tested as a source of estrogens, the alcohol was first removed. They tested the equivalent of one can of beer a day for one month on the hormone levels of post-menopausal women, so as not to confound the results with endogenous estrogens, and they found significant alterations of hormonal levels during the beer month, and then coming back to baseline a week afterwards. But does this have any clinical effects, either good or bad? A cross-sectional study of about 1,700 women found that beer drinkers appeared to have better bone density, perhaps because of the proestrogenic effects? They don't recommend women start drinking beer for bone health, but suggested they may have beneficial bone effects for women who already drink. What about helping with hot flashes? About half of post-menopausal and perimenopausal women in the US suffer from hot flashes, whereas the prevalence in Japan, maybe 10 times lower, presumed to be because of their soy consumption. What about hops? There have been a few studies like this, and this showing potential benefit, leading to this 2013 review suggesting that hop extracts may be somewhat effective in treating menopausal discomforts. But that was before this study, which reported extraordinary results with about a half teaspoon of dried hops flowers. For example, hot flashes on the bottom, in the placebo group on the right there, women started out having about 23 hot flashes a week, and throughout the three-month study, continued to have 23 hot flashes a week. In the hops group, they started out even worse, but then down to 19 at the end of the first month, then 9, then just once a week, basically, and similar findings were reported for all the other menopausal symptoms measured. But hey, animal astrogens work too. Millions of women used to be on horse hormones, premmering from pregnant meriurin. That took care of hot flashes too, and curtailed osteoporosis, but caused a pesky little side effect called breast cancer. Thankfully, when this was realized, and millions of women stopped taking it, breast cancer rates fell in countries around the world. This is data from California. The question then is, are the astrogens in hops more like the breast cancer promoting horse astrogens, or the breast cancer preventing soy astrogens? The key to understanding the health protective potential of soy phytoastrogens is understanding the difference between the two types of estrogen receptors. There's alpha receptors and beta receptors. Unlike animal estrogen, the soy phytoastrogens bind preferentially to the beta receptors, and in breast tissue they're like Yin and Yang, with the alpha receptors signaling breast cell proliferation, explaining why horse hormones increase breast cancer risk, whereas the beta receptors, where the soy binds, opposes that proliferative impact. So does the hops phytoastrogens prefer beta 2? No, 8 p.m. is a selective estrogen receptor alpha promoter. Surprisingly, in clear contrast to the soy, 8 p.m. is a much weaker binder of beta than of alpha, so that explains why hops is such a common ingredient in so-called breast-enhancing supplements, because it acts more like estrogen-astrogen. Given the breast cancer concerns, use of such products should be discouraged. But just drinking beer could provide the exposure to the hops estrogen, as is found in these kinds of products, which could help explain why beer may be more carcinogenic to the breast than some other forms of alcohol.