One of the biggest dangers to your immune system–making you more vulnerable to illnesses like multiple sclerosis and lupus–may be what you eat for dinner tonight.
A study at the University of Michigan shows that for younger women of childbearing age, eating seafood that is high in mercury can increase the risk of autoimmune difficulties, stimulating immune cells to attack healthy tissue. These types of illnesses primarily affect women and currently afflict 50 million Americans.
“We don’t have a very good sense of why people develop autoimmune disorders,” says researcher Emily Somers. “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.”
The researchers note that autoimmune conditions like rheumatoid arthritis, lupus, inflammatory bowel disease, Sjorgen’s syndrome and multiple sclerosis are in the top 10 causes of death among American women.
The seafood high in mercury that you should avoid includes king mackerel, swordfish and tilefish. Safer seafood lower in mercury includes salmon, shrimp and canned light tuna.
In this study, researchers examined health information concerning women ages 16 to 49 contained in the National Health and Nutrition Examination Survey conducted from 1999 to 2004. Women who were exposed to more mercury in their seafood displayed higher levels of autoantibodies – immune cells that can attack the body’s own tissues. Accumulating autoantibodies often presages the development of autoimmune disease.
“The presence of autoantibodies doesn’t necessarily mean they will lead to an autoimmune disease,” Somers says. “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. 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.”