Study indicates that high mercury in fish overrides health benefits by omega 3s . By David McGuire, Got Mercury
A new study indicates that Omega-3 fatty acids and mercury, both found in fish, appear to have opposing affects on cardiac health and risk of myocardial infarction.
This study published in the
American Journal of Clinical Nutrition, looked at data from more than
1,600 men from Sweden and Finland. Men with high levels of
mercury in their body had an increased risk of heart attacks, while
those with a high concentration of omega-3s had a lower risk.
Predatory fish such as shark, swordfish, kind
mackerel and tilefish are at the top of the marine food chain and for
that reason concentrate mercury from the environment in their tissues. Methyl mercury is known to be toxic to the nervous system, especially in
fetuses and children. The US Federal Drug Administration and the U.S. Environmental Protection Agency warns
women of childbearing age and children against eating predatory fish and that men and women outside the ages minimize their consumption of high mercury fish.
men in the study submitted hair and blood samples to measure their
mercury and omega-3 levels, as well as information on their health and
The average mercury level among the Swedish men was
0.57 micrograms per gram of hair, and more than twice as high in their
Finnish peers. Swedes also had higher levels of omega-3s than did
The study reports found that men with at least 3 micrograms
of mercury per gram of hair had an increased risk of heart
attacks compared with men with 1 microgram per gram only of the subjects also had low levels of omega-3 fats. For men with higher Omega-3s,
it took higher levels of mercury to see an increased heart attack risk,
suggesting the two compounds might have opposite effects on cardiac health.
Got mercury has found that other fish such as tuna have high levels of mercury, and that the levels vary between where the fish was caught and what type of tuna. In general, smaller fish that do not accumulate mercury have the benefits of Omega-3s without the risk of mercury.
Full study here http://ajcn.nutrition.org/content/early/2012/08/15/ajcn.111.033795.abstract?sid=76865977-6cc0-474c-b07f-e496eb4dc834