A new study entitled “Mercury Exposure and Antinuclear Antibodies among Females of Reproductive Age in the United States” suggests mercury exposure by seafood may increase the risk of developing autoimmune diseases in women. The study was published in the journal Environmental Health Perspectives.
Autoimmune disorders occur when the body’s immune system attacks and damages its own healthy tissues. Females are at a significantly higher risk to suffer from autoimmune disorders when compared to men, as nine females are affected for every one male. Autoimmune diseases such as multiple sclerosis are one of the 10 leading causes of death in women.
Autoimmunity is characterized by the lack of tolerance towards the body’s self-antigens. However, it can exist without clinical symptoms as well, accounting for a pre-clinical immune dysregulation. One of the factors associated with immune dysregulation is exposure to mercury, with mice studies supporting immunotoxic effects caused by mercury exposure (organic and inorganic forms).
A research team from the University of Michigan determined the association between mercury exposure and the presence of antinuclear antibodies (ANA), i.e., antibodies that are produced by the immune system when immune dysregulation occurs. Mercury biomarkers included hair mercury, (indicates predominantly organic [methyl] mercury); total blood mercury (biomarker for both organic and inorganic mercury); and urinary mercury, a marker for inorganic/elemental mercury.
Researchers analyzed a total of 1,352 women aged between 16 to 49 years old from the National Health and Nutrition Examination Survey performed from 1999 to 2004. They found that a greater exposure to mercury was associated with higher levels of autoantibodies in females during reproductive ages, with organic (methyl) mercury accounting for the most predominant factor. Importantly, seafood is one of the richest sources for this type of mercury.
The authors highlight that while fish consumption is recommended for pregnant women, they should pay particular attention to the type of fish they consume, as noted by Emily Somers, Ph.D., Sc.M, study leading author, in a press release: “In our study, exposure to mercury stood out as the main risk factor for autoimmunity. The presence of autoantibodies doesn’t necessarily mean they will lead to an autoimmune disease. 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.”