Omega-3 fatty acids are found in oily fish including salmon and trout, as well as nuts. They are associated with a decreased risk of heart problems.
According to Health Day News, the Canadian researchers surveyed Inuits in northern Quebec because their traditional diet is seafood heavy. They found that the Inuits studied had a blood mercury level much higher than that of the general U.S. population.
The researchers also discovered a correlation between higher blood mercury levels and small increases in blood pressure.
Experts advise avoiding fish that carry the highest mercury levels, which include tuna and swordfish.
The study appears in the latest issue of Hypertension.