Toenail study finds that mercury from eating fish doesn't raise risk of heart disease, stroke (USA)

In an unusual health study, researchers analyzing toxin levels in tens of thousands of toenail clippings determined that mercury from eating fish does not raise the risk of heart disease or stroke. Health experts have long urged people to eat fish to lower heart risks, but some have worried that the mercury in certain types of fish like shark and swordfish might offset any benefits. Earlier studies on mercury and heart problems in adults have yielded contradictory results. The latest government-funded work is the largest to look at this question. Instead of relying on what people said they ate, it measured mercury in their toenails - a good gauge of long-term exposure to the metal from fish consumption. No differences were seen in the rates of heart and stroke among those with the highest concentrations of mercury compared to those with the lowest. "The average person should eat fish as part of a healthy diet," and not worry about ill heart effects, said Harvard School of Public Health cardiologist Dr. Dariush Mozaffarian, who led the research published in The New England Journal of Medicine

Mercury in fish seems to raise blood pressure in spite of nutrients

The negative impact of high amounts of methylmercury in seafood on blood pressure may outweigh the protective effects of fish nutrients, researchers report in Hypertension: Journal of the American Heart Association. Researchers found that even when blood pressure was within the normal range and numerous other factors, including omega-3 fatty acids (essential fats that your body needs to function properly but does not make) and selenium (a dietary essential mineral) were carefully controlled for, the environmental mercury was associated with higher blood pressure and pulse pressure among Nunavik Inuit adults in a recent study - AHA