Trans Fats, Childhood Obesity Increase Endometriosis Risk


Two recent studies have implicated diet and weight in the development of painful endometriosis which affects millions of women. The Endometriosis Research Center celebrates March as Endometriosis Awareness Month to educate women on how to reduce the risk and help provide relief for symptoms.

Endometriosis occurs when pieces of the uterine lining, called the endometrium, is found outside the organ. The tissue continues to grow in response to estrogen, but because it cannot be shed during menstruation, it is trapped and may spread to other organs. This can lead to severe pain and sometimes infertility. It afflicts about 10% of women and there is not currently a cure for the condition.

The first study, conducted by researchers at the Brigham and Women’s Hospital and Harvard Medical School in Boston MA, followed almost 71,000 American nurses enrolled in the US Nurses Health Study for 12 years. Using food-frequency questionnaires, Dr. Stacey Missmer, lead author, and team found that women whose diets are high in trans fatty acids had a 48% higher chance of developing endometriosis.


Trans fats are artificially produced from liquid vegetable oil. A process called hydrogenation makes the liquid into a solid fat to be used in the production of many processed foods. Major sources include fried restaurant food, margarine, crackers, and snack foods. Trans fats increase the body’s level of many inflammatory markers that are associated with the establishment and progression of endometriosis.

The Boston study, published online in the journal Human Reproduction, also found that long-chain omega-3 fatty acids may help women reduce their chance of developing endometriosis. Women who ate the highest amounts were 22% less likely to be diagnosed. These fats are mostly found in oily fish, such as tuna, salmon, and mackerel.

A second study of over 500 Australian women, conducted at the Queensland Institute of Medical Research, Dr. Christina Nagle and colleagues found that being overweight early in life (at age 10) doubles the chance of eventually developing endometriosis.

The team also found that women having severe menstrual cramps at an early age can double the risk as well and that girls who began their periods after the age of 14 had a decreased risk of the condition.

"Millions of women worldwide suffer from endometriosis. Many women have been searching for something they can actually do for themselves, or their daughters, to reduce the risk of developing the disease, and these findings suggest that dietary changes may be something they can do. The results need to be confirmed by further research, but this study gives us a strong indication that we're on the right track in identifying food rich in Omega-3 oils as protective for endometriosis and trans fats as detrimental," Dr. Missmer added.