The two recent government-sponsored reports released on Tuesday revealed that eating fish regularly is beneficial in spite of the risks due to contamination. These reports are based on reviews of earlier studies.
"Overall, for major health outcomes among adults, the benefits of eating fish greatly outweigh the risks. Somehow, this evidence has been lost on the public," said Dr. Dariush Mozaffarian, an instructor in epidemiology at the Harvard School of Public Health and lead author of a review published Wednesday in The Journal of the American Medical Association.
The National Heart, Lung and Blood Institute supported the study. Another study was carried out by the Institute of Medicine. This study supports government dietary advice of fish being a part of a healthy diet, however, women who are likely to conceive or are pregnant or breastfeeding should be careful about the risk of exposure to contaminants.
"The bottom line is, the IOM report complicates the issue rather than clearing anything up," said Jennifer Sass, a scientist with the Natural Resources Defense Council. Malden Nesheim, a professor emeritus of nutrition at Cornell University and chairman of the Institute of Medicine committee, said, "The panel actually found slim evidence for many claims about the health benefits of fish as well as the dangers. We were surprised at the lack of reliable data on the distribution of contaminants in our seafood supply or on how the benefits might counteract the risks."
However, both the studies agreed on the point that there is a reduction in risk of developing heart disease by consumption of fish and shellfish. According to the Harvard report, there is a 35% decrease in the risk of death from heart disease by fish consumption.
"We also found that fish or fish oil intake reduces total mortality by 17 percent, a remarkable reduction considering that this is the benefit for deaths from all causes," Mozaffarian said.
Methylmercury contamination has been the major cause of concern in consumption of seafood. This heavy metal has been associated with learning disabilities and developmental delays in children and to heart, nerve and kidney damage in adults.
"The controversy has been pretty one-sided, dominated by those who feel low levels of mercury impair cognitive development," said Dr. Gary Myers, a neurologist at the University of Rochester in New York.
He was associated with one of the biggest studies following prenatal mercury exposure from fish against long-term development, however, not with these two studies.
"Now, we seem to be looking a little more at the more general issues of nutrition from fish."
Omega-3 fatty acids and other essential nutrients from the seafood play a role in early development of brain in infants. However, government has advised women of childbearing age and young children to avoid large predatory fish due to the fear of mercury contamination. The Institute of Medicine committee has recommended those groups to consume at least two servings (6 ounces) of fish a week, and can safely consume up to 12 ounces. Younger children are advised by the FDA to consume smaller portions.
"If they really wanted to help high-risk consumers and bring others back to the fish counter, the panel would have supported posting information on mercury in stores, like those that are already being posted by some grocery chains," said Caroline Smith-DeWaal of the Center for Science in the Public Interest, a food watchdog group.