Even though the world's fish contain slight amounts of mercury, eating lots of fish carries no detectable health risk from low levels of the substance, even for very young children and pregnant women, concludes the most comprehensive study of the subject yet.
The findings come from a nine-year University of Rochester study conducted in the Republic of the Seychelles, an island nation in the Indian Ocean where most people eat nearly a dozen fish meals each week and whose mercury levels are about 10 times higher than most U.S. citizens. Indeed, no harmful effects were seen in children at levels up to 20 times the average U.S. level. The work is published in the August 26 issue of the Journal of the American Medical Association.
"We look at the Seychelles people as a sentinel population," says pediatric neurologist Gary Myers, who examined the children. "If somebody who eats fish twice a day does not show effects from mercury exposure, it's unlikely that somebody who eats fish twice a week will be affected. And the fish they eat in the Seychelles contains the same amount of mercury as fish sold at supermarkets and eaten in the United States."
Adds first author Philip Davidson, an expert on developmental disabilities who designed a battery of the most sophisticated tests available to examine the children: "What we found in the Seychelles is applicable to every woman, every man, and every child around the world who eats ocean fish."
In the United States the green light applies only to fish
bought and sold commercially, at grocery stores, supermarkets,
fish shops, and in restaurants. Those fish are already regulated
based on their mercury levels, and current regulations are
sufficient to safeguard frequent fish eaters against mercury
exposure, say the investigators. Consumers still should follow
advisories about eating fish caught in lakes and rivers, since
Contact: Tom Rickey
University of Rochester