by Crystal Phend
Senior Staff Writer, MedPage Today

03.03.2014

SAN DIEGO — Anti-inflammatory plant estrogen compounds found in soy and flaxseed were associated with less asthma and allergic disease, a national observational study showed.

People with the highest urinary levels of phytoestrogens from flax and soy had the lowest risk, Jessica Savage, MD, MHS, of Brigham and Women’s and Harvard in Boston, reported here at the American Academy of Allergy, Asthma, and Immunology meeting.

“It may actually be beneficial to eat flaxseed, which is a simple thing to do, or to take some kind of probiotic,” she said, “that would help [turn] the precursors of the lignan into enterolactone to help either prevent asthma or treat wheezing and other respiratory diseases.”

Wheezing was 41% less likely in those with enterolactone levels in the top versus bottom third and 34% less likely for the top versus bottom tertiles by o-desmethylangolesin, both statistically significant for odds and trend.

Aeroallergen sensitization was 27% less likely with daidzein levels in the top versus bottom third, again significant for odds and trend.

Asthma risk fell 9% overall and 13% in children per natural log higher enterolactone in adjusted analyses, also statistically significant associations.

Savage cautioned that her group’s cross-sectional analysis of National Health and Nutrition Examination Survey data (2003-2006 and 2009-2010) couldn’t determine causation.

“One potential criticism of the study is that people who wheeze are generally less healthy, and may be less likely to eat these foods in their diet,” she told reporters at a press conference.

“However, given that the microbiome is so important in converting these foods and converting these chemicals into the the phytoestrogens, it’s not clear how important that criticism is at this point,” she added.