Researchers at the University of Michigan analyzed diet surveys and mercury levels of more than 1,300 women between the ages of 16 and 49. They also tested the women’s blood for antinuclear antibodies (ANA), or proteins that attack the body’s own tissues and may be an indicator of full-blown AI disorders. The scientists found that women with the highest organic mercury exposure—from one-fourth to almost six times the EPA’s recommended maximum!—had higher rates of ANAs than women with less exposure. Mercury was also the strongest predictor of ANA positivity: Surprisingly, neither age nor smoking showed an association with ANAs. MORE: 8 Surprising Conditions Postmenopausal Women Are At Risk For Researchers note that just because you have ANAs in your blood, doesn’t mean you’ll definitely develop an AI disease: Research shows that as much as 15% of the population will test positive for ANAs and still be healthy. But ANAs are still considered an important predictor of AI diseases and could be a particularly key consideration for women, who are nine times as likely as men to develop an AI condition. To reduce your mercury consumption, steer clear of seafood containing moderate to high amounts of the toxin, including swordfish, shark, king mackerel, gulf tilefish, marlin, fresh tuna, halibut, grouper, Chilean sea bass, bluefish, and sablefish. Keep an eye on your canned tuna consumption, too: A recent Consumer Reports analysis recommends that a 132-pound person consume no more than 4 ounces of albacore and 11 ounces of light tuna per week. Love seafood? Focus on low-mercury species like scallops, sardines, wild salmon oysters, domestic squid, and domestic tilapia. Other safe choices include haddock, pollock, flounder, domestic crawfish, catfish, trout, crab, and Atlantic mackerel. MORE: The New Rules Of Eating Fish