WASHINGTON (Reuters) - Pregnant and breast-feeding women should eat at least 12 ounces (340 grams) of fish and other seafood a week because the benefits for infant brain development outweigh any worries about mercury contamination, a group of U.S. experts said on Thursday.
The recommendations contradict U.S. government warnings that these women should consume no more than 12 ounces of fish and other seafood weekly due to concerns that mercury -- which can harm the nervous system of fetuses -- might exist in trace amounts in this food.
But the group of 14 obstetricians and nutritionists said the threat of mercury poisoning remains only theoretical, while the warnings have scared many pregnant women into not eating fish at all, robbing them and their babies of vital nutrients like omega-3 fatty acids, known to help brain development.
The recommendations were issued in partnership with the National Healthy Mothers, Healthy Babies Coalition, whose members include the Centers for Disease Control and Prevention, the Agriculture Department, the March of Dimes, the American College of Obstetricians and Gynecologists and others.
The nutrients in fish and seafood are important for brain and motor skill development in children and can help prevent postpartum depression in mothers, the experts said.
The coalition said it received $60,000 from a seafood industry trade group, but the experts defended the independence of their work.
"There has been no case of fetal mercury toxicity due to fish consumption reported in the United States," said one of the experts, Dr. Ashley Roman, a professor of obstetrics and Gynecology at New York University Medical Center.
The group urged that women who want to become pregnant, are pregnant or are breast-feeding should eat a minimum of 12 ounces per week of fish like salmon, tuna, sardines and mackerel and seafood like shrimp, lobster and clams.
That amounts to about two to three servings a week. It did not state a recommended upper limit for consumption.
"There are some fish that have been shown to be higher in mercury and in other important trace elements such as shark and swordfish," Roman said. "Those might be sources of fish women still might want to stay away from. But the vast majority of fish out there present in the U.S. diet, those are generally very healthy fishes."
"We're not saying that women should eat 21 meals a week of fish. That's not the message here," added Cornell University nutritionist Thomas Brenna, another member of the group.
The experts cited a study published in February in the Lancet medical journal finding that children whose mothers ate more fish and other seafood while pregnant were smarter and had better developmental skills than those whose mothers ate less or none.
It looked at children of 8,000 British women to see how children fared if their mothers ate more than 12 ounces a week.
The U.S. Food and Drug Administration and U.S. Environmental Protection Agency issued advisories in 2001 and 2004 telling women who were pregnant, breast-feeding or trying to become pregnant, as well as young children, to eat no more than 12 ounces weekly of some types of fish due to mercury concerns.
Estimates on the dangers posed by mercury come from people exposed in chemical spills. No major studies have shown that mercury from food or vaccines has caused brain damage to mothers or children.
"While it's recognized that fish is an important source of protein, especially for pregnant women, this new emphasis on eating more than 12 ounces of fish per week, without mention of the need to avoid mercury-contaminated fish, appears to throw the baby out with the bath water," Michael Bender, director of the Mercury Policy Project advocacy group that believes mercury exposure has damaged children, said in a statement.
Additional reporting by Maggie Fox