Mercury in tuna still a concern 1/11
(This article is adapted from the January 2011 Consumer Reports magazine.)
Canned tuna, Americans’ favorite fish, is the most common source of mercury in our diet. Consumer Reports’ new tests of 42 samples from cans and pouches of tuna bought primarily in the New York metropolitan area and online confirm that white (albacore) tuna usually contains far more mercury than light tuna.
Children and women of childbearing age can easily consume more mercury than the Environmental Protection Agency considers advisable simply by eating one serving of canned white tuna or two servings of light tuna per week. A serving is about 2.5 ounces. Expect a 5-ounce can to contain about 4 ounces of tuna plus liquid.
The heavy metal accumulates in tuna and other fish in an especially toxic form, methyl -mercury, which comes from mercury released by coal-fired power plants and other industrial or natural sources, such as volcanoes.
Fortunately, it’s easy to avoid tuna and to choose lower-mercury fish that are also rich in healthful omega-3 fatty acids. That’s especially important for women who are pregnant or might become pregnant, nursing mothers, and young children, because fetuses and youngsters seem to face the most risk from methyl mercury’s neurotoxic effects.
How much tuna is safe
Canned tuna, especially white, tends to be high in mercury, and younger women and children should limit how much they eat. As a precaution, pregnant women should avoid tuna entirely.
Because Consumer Reports’ analysis of FDA data found occasional high mercury levels in light tuna, our fish-safety experts suggest a more cautious approach than that of the FDA and EPA. Our experts’ advice, below, assumes that no other mercury-containing seafood will be eaten during the same week.
||Limit per week
|Children less than 45 pounds
||About 4 ounces of light tuna or 1.5 ounces of white (albacore) tuna.
|Children 45 pounds or more
||About 4 to 12.5 ounces of light tuna or 1.5 to 4 ounces of white tuna depending on the child’s weight.
||To be careful, avoid canned tuna. Choose a low-mercury fish instead.
|Women of childbearing age
||About 12.5 ounces of light tuna or 4 ounces of white tuna.
|Men and older women
||About 14.5 ounces of light tuna or about 5 ounces of white tuna per week should be OK, but people who eat fish more often would be prudent to stick to low-mercury types.
Other fish choices
In addition to avoiding tuna, four other high-mercury fish—king mackerel, shark, swordfish, and tilefish—also should be avoided by children and women of childbearing age, according to federal agencies.
Consumer Reports experts say the fish species below are low in mercury and good sources of omega-3 fatty acids. The limits assume that no other mercury-containing seafood will be eaten during the same week and are based on a daily serving of about 6 ounces for adults and 3 ounces for young children.
|Clams, Alaskan salmon, shrimp, and tilapia
||OK daily for everyone.
|Oysters, pollock, and sardines
||OK daily for all adults. For children, oysters and sardines OK daily; pollock several times a week.
|Pacific flounder and sole, herring, mullet, and scallops
||OK daily for men and postmenopausal women, several times a week for children and women of childbearing age.
Fish Q & A 1/11
Seafood: green buying guide 10/10