Top brands of tuna found high in mercury

A new study in the Feb 2010 issue of Environmental Toxicology & Chemistry found that mercury in tuna is higher than expected.

Tuna is not on the warning list and advocate groups have warned early that some brands of tuna are high in mercury and asked the Food and Drug Administration to update its fish consumption advisory which was jointly issued by the FDA and the Environmental Protection Agency.

The current EPA/FDA fish consumption advisory issued in 2004 says that women and young children should not eat shark, swordfish, king mackerel or Tilefish because they contain high levels of mercury.

However, the advisory also suggests that women and children benefit from eating fish, and should include up to 12 ounces a week of a variety of fish and shellfish that are lower in mercury including the five most commonly eaten types - shrimp, canned light tuna, salmon, Pollock and catfish.

The advisory does acknowledge that albacore tuna is higher in mercury than canned light tuna, but also says that "when choosing your two meals of fish and shellfish, you may eat up to 6 ounces of albacore tuna per week.”

Researchers at the University of Nevada-Las Vegas found 55% of more than 300 samples of canned tuna from the top three brands in the United States had mercury levels higher than the EPA standard 0.5 parts per million and 5% even higher than 1.0 ppm safety up-limit set by the FDA for commercially sold fish, Healthday.com reported.

Mercury, particularly methyl mercury, the organic form of mercury found in seafood, is a highly toxic substance that can damage the brain functions in high doses.

Shawn Gerstenberger, coauthor of the study, and colleagues found huge difference in mercury levels among the brands and types of tuna.  One of the three was consistently high in mercury.  All three brands of white tuna, which is made from albacore, were high in the chemical.

The authors urged the U.S. government to revise its recommendation on fish consumption to better protect U.S. consumers from mercury poisoning.

For the safety information, consumers should check out their state's fish consumption advisory on local fish conditions.  Most states have their advice on which types of fish caught from where should not be consumed because of contamination.

Photo from fpir.noaa.gov

By David Liu and editing by Denise Reynolds