What Does This Mean for Women Trying to Conceive?
The study shows that for every two percent increase in calories coming from trans fats instead of carbohydrates, women have a 73 percent increased risk for infertility, and the risk rises to 79 percent when trans fats are replacing omega-6 polyunsaturated fats. And, it doesn’t take a lot of trans fats to impact fertility—women consuming just four grams a day are at risk. (See Which Foods Are High in Trans Fats to learn how little that is.)
The effects of trans fats on women with polycystic ovarian syndrome (PCOS) may be even more dramatic, because trans fats seem to amplify the symptoms of PCOS. The Harvard study showed that trans fats can interfere with the cell receptor activity that is involved with inflammation, glucose metabolism, and insulin sensitivity, making it more difficult for women with PCOS to conceive.
Harvard researchers Jorge Chavarro, MD, and Walter Willett, MD, have written a book covering this and other findings from the long-term study, called The Fertility Diet. In short, they write, "Across the board, the more trans fats in the diet, the greater the likelihood of developing ovulatory infertility." The authors stress that their advice is not to give up fats altogether. Just trans fats.
As Drs. Chavarro and Willett say, "Think of trans fats as the evil cousins of the healthy omega-3 fats in fish, flaxseeds, and walnuts." (For an excerpt from their book, check out 10 Steps to Increasing Your Fertility.)