Phytoestrogens, estrogen-like chemicals found in some plants, could play a role in preventing or even treating allergies and asthma, according to a large study presented at the annual meeting of the AAAAI.
A nationally representative sample reveals that increased levels of phytoestrogens and associated compounds in urine are associated with lower levels of asthma and allergy. Sources of phytoestrogens include beans, soy, peas, lentils, flax, millet and rye.
For the study, researchers examined urine samples from more than 10,000 participants in the National Health and Nutrition Examination Survey. By also looking at patient histories, it was found that urinary levels of the compounds daidzein, O-DMA, and enterolactone were associated with lower chances of wheezing and asthma, and also lower IgE levels and odds of being sensitized to aeroallergens.
“The major sources are flax seeds and soy, but importantly, it takes both dietary sources and the correct bacterial microbiota in the gut to manufacture these chemicals,” notes study author Dr. Jessica Savage of Harvard Medical School.
But the picture is complicated by the fact that phytoestrogens have had mixed reviews. They’ve been associated with benefits including reduced risk of cancer and cardiovascular disease, while at the same time they’ve been linked with increased cancer risk and developmental issues. Still, it’s possible that new, safe asthma drugs that make use of phytoestrogens could be developed.
“Increased consumption of phytoestrogens may help prevent or treat asthma and allergic disease,” the authors conclude.