No link between mercury in fish and heart disease found in study

Eat fish. And don’t stress -- overly much -- about the potential effect of its mercury level on your risk of cardiovascular disease. That ultimately might be the lesson from a new study assessing the effect of mercury exposure via fish consumption.

Researchers examined toenail clippings of 3,427 men and women with cardiovascular disease, comparing them with the clippings of 3,427 people without cardiovascular disease. They then measured the amount of mercury and selenium concentrations in the toenail samples of those who had heart disease. (Selenium appears to offer some protection against mercury poisoning, so they figured they’d better measure that too.)

Their conclusion, as presented in the abstract that was released Wednesday in the New England Journal of Medicine: “We found no evidence of any clinically relevant adverse effects of mercury exposure on coronary heart disease, stroke, or total cardiovascular disease in U.S. adults at the exposure levels seen in this study.”

But, the researchers pointed out in a discussion of their work, it’s possible that mercury can affect cardiovascular disease risk at higher levels than they found or when there’s a lack of selenium (rare in this country).

So keep trying to reduce mercury contamination in fish and the environment overall, they said, adding that such contamination “could still have the potential to offset, at least in part, the net cardiovascular benefits of fish consumption.”

Fish, of course, has been touted as heart-healthy food for the omega-3 fatty acids contained in fish oil. (Specifically, that¿s DHA (docosahexaenoic acid), ALA (alpha-linolenic acid) or EPA (eicosapentaenoic acid). This Los Angeles Times story explains the benefits derived from fish oil in protecting your heart.

But chances are you already know that. A ConsumerLab.com survey earlier this year suggests that fish oil supplements are the most popular dietary supplements in America.