Got Estrogen? Milk Study Says Yes.

While we are aware of the overwhelming estrogenic effects of rBGH (recombinant bovine growth hormone) in dairy products, researchers have proven for the first time that the feed cows consume may also be contributing to the over-estrogenization of the American population.

According to a study published last week in the American Journal of Clinical Nutrition, a staple foodstuff of the American dairy cow is soy, which is a crop naturally high in phytoestrogen. In addition, most soy is conventionally grown, which contains highly estrogenic pesticide residue. Hence, even if American cows are rBGH-free, if not grass-fed, they are still walking estrogen factories.

Researchers measured equol concentrations, an estrogenic urinary metabolite which has been recently linked to estrogen-related cancers, including breast and prostate, in human subjects. According to the study, "the significant correlates for equol concentration were frequency of dairy consumption and daidzein intake, but a stronger correlation was observed with dairy products. These results suggest that, for the overall population, equol concentrations likely reflect the intake of foods of animal origin that contain equol. Unlike soy consumption in the US population, dairy product consumption is frequent. In our study population, 80% of individuals reported consuming dairy products at least once per day. Individuals who consume dairy frequently may have a low-level, chronic exposure to equol."

Low levels of equol exposure in some studies, primarily from the European Prospective Investigation into Cancer and Nutrition study (EPIC), suggest that urinary equol concentrations in low-soy-consuming populations may be positively or inversely associated with breast cancer risk, but other studies have observed no association between urinary equol and risk of colorectal or prostate cancer. The observations suggest that equol intake from foods of animal origin may influence disease risk, but consideration of the independent or interactive roles of equol and of dairy products is important. Equol is hypothesized to influence colorectal cancer risk through estrogenic effects on cell proliferation.

In conclusion, in individuals with detectable equol concentrations, dairy consumption significantly correlated with urinary equol, which may also have contributed to be the high percentage of individuals with detectable equol concentrations observed in this population.

What does this groundbreaking study really say? Cows should be eating a diet that is genetically compatible: grass! It also says that the estrogenic load Americans are exposed to is unsustainable. Environmental exposure alone in the form of plastics, pesticides, drug byproducts, pollution, among others, is enough. We do not need to compound the problem with estrogenic dairy products.