Two senators are urging the Food and Drug Administration to revise its recommendations on how much fish pregnant and nursing women can safely eat.

In a letter to FDA Commissioner Margaret Hamburg, Sens. Kirsten Gillibrand (D-NY) and Tom Coburn (R-OK) ask that the agency’s recommendations be changed to reflect those of the recently released 2010 Dietary Guidelines for Americans.

The letter, which was signed by 16 other lawmakers, goes on to say the FDA’s current advice has caused people to eat less seafood.

Both the FDA and the Environmental Protection Agency have suggested that younger women and children limit consumption of seafood to 12 ounces per week, limit albacore tuna intake to 6 ounces per week and avoid eating swordfish, shark, king mackerel and tilefish entirely because of health risks linked to methylmercury.

“While the (FDA-EPA guidance) is in many ways medically accurate, the recommendations communicate an overly risk-averse, precautionary principle that has led to unhealthy reductions in seafood consumption among pregnant women,” Coburn and Gillibrand wrote in their letter.

Gillibrand, in a news release Monday, said the six-year-old guidance is out of date and inconsistent with the new dietary guidelines, which say the benefits of seafood far outweigh the risks, even for pregnant women.

For the first time, the government’s revised Dietary Guidelines, which serve as the basis for federal nutrition policy, advise all Americans, including pregnant and breastfeeding women, to eat seafood at least twice a week for heart and brain benefits. The previous guidelines limited the twice-a-week recommendation to heart patients.

Gillibrand and Coburn asked Hamburg to respond to their letter within 30 days.

Late last year, Consumers Union, the nonprofit publisher of Consumer Reports, asked the FDA to take a more cautious approach in regards to canned tuna, which remains the most popular fish in the U.S. and the most common source of mercury in the American diet.

After testing cans of tuna, the group said it found that white (albacore) tuna usually contains more mercury than light tuna. Consumers Union said it believes pregnant women should be advised to avoid tuna altogether, because of mercury’s potential effects on fetal development.  

When the advocacy group made that announcement in December, several industry groups, including the Western Fishboat Owners Association (WFOA), criticized the Consumer Union study as misleading, and said  it “ignores good science that shows U.S. troll-caught albacore mercury levels to be similar to that of light tuna,” which the FDA lists as safe.

WFOA added, “We believe that the benefits of consuming quality seafood far outweigh any risk for the vast majority of people, and that the hyperbole associated with some of these mercury campaigns does more to damage consumers’ health by driving them to less healthful foods.”