Exposure to mercury from sources such as contaminated seafood could be a top risk factor for autoimmunity in women of childbearing age.
Researchers found mercury contributed to autoimmunity in this group, even if consumed at levels generally considered to be safe, the University of Michigan Health System reported. Autoimmune disorders cause the body's immune system to attack healthy cells, and is more prominent in women.
"We don't have a very good sense of why people develop autoimmune disorders," said lead author Emily Somers, an associate professor in the departments of Internal Medicine in the division of Rheumatology, Environmental Health Sciences, and Obstetrics & Gynecology at the U-M Medical and Public Health Schools. "A large number of cases are not explained by genetics, so we believe studying environmental factors will help us understand why autoimmunity happens and how we may be able to intervene to improve health outcomes. In our study, exposure to mercury stood out as the main risk factor for autoimmunity."
To make their findings a team of researchers looked at data on women between the ages of 16 and 49 from the National Health and Nutrition Examination Survey, which spanned from 1999 to 2004. They found a greater exposure to mercury was linked to a higher rate of autoantibodies in these women.
"The presence of autoantibodies doesn't necessarily mean they will lead to an autoimmune disease," Somers said. "However, we know that autoantibodies are significant predictors of future autoimmune disease, and may predate the symptoms and diagnosis of an autoimmune disease by years."
Most fish consumption recommendations are aimed at pregnant women and those either nursing or trying to conceive, these findings suggest all women of childbearing age should be wary of the type of fish they are consuming.
"For women of childbearing age, who are at particular risk of developing this type of disease, it may be especially important to keep track of seafood consumption," Somers concluded.
The findings were published in a recent edition of the journal Environmental Health Perspectives.
