This past Thursday, actor Jeremy Piven from HBO's "Entourage" withdrew from his role in the Broadway play "Speed-the-Plow" due to high levels of mercury in his bloodstream. The Food Section, fellow food blog, states that Piven's doctor, Dr. Carlon Colker, attributes such high levels to a diet of sushi twice a day. Sounds like Piven is going to have to lay off the Sushi for a while.

The Piven incident supports evidence that fish has high levels of mercury that can become toxic in large quantities. Just this past September, I posted about the controversy over the FDA's refusal to acknowledge tuna's mercury toxicity. What's worse? According to a recent article from The Washington Post, the FDA is urging the government to reverse its advisory that women and children should limit how much fish they eat.

The Washington Post article explains that mercury damages the neurological development of fetuses and infants, and it poses a health risk for adults, such as the increased risk of cardiovascular disease. The article's information was based on scientific studies. What will it take for the FDA to recognize that too much of certain fish can be toxic?

A study done by the Sea Turtle Restoration Project looked at tuna samples from 6 of the most popular sushi restaurants in Los Angeles and found average mercury levels of 0.721 parts per million. The group is claiming that these mercury levels are dangerously high and describing the risk of eating it as a “new Russian roulette.”

However, other sources, like the nonprofit Center for Consumer Freedom, say that the group’s study is deeply flawed. For example, the FDA’s maximum allowable level of mercury in tuna is 1 part per million, a level that is above the average found in the study.

Not only was most of the tuna below the federal mercury standard, but the standard is based on a number that is 10 times less than the amount that is associated with health risks. Mercury does, however, remain in the body and builds up over time. While the risk of eating a piece of sashimi may not be as high as the Sea Turtle Restoration Project claims, it is still fact that consuming a lot of tuna can increase your risk for mercury related health problems, which can include memory loss and damage to the nervous system. Other concerns about the study stem from the possible ulterior motives of the Sea Turtle group. Because it is not a consumer health group but an environmentalist organization, they may be hoping to stop certain areas from being fished rather than actually looking out for the safety of sushi eaters.

Canned tuna has been tested safe by the FDA. After hearing increasing warnings about the levels of mercury in seafoods - particularly canned tuna - the United States Tuna Foundation (USTF) has reported that Food and Drug Administration tests have proven that canned tuna contains less mercury than the national allowance. It is recommended that no more than 1 part per million (ppm) of mercury should be consumed daily, and the canned tuna tested averaged 0.12 ppm, approximately 8 times less than the limit for commercial fish. The USTF director, David Burney, said that the "FDA's latest findings about mercury levels in canned tuna should end the debate over whether canned tuna is a safe and healthy food for all Americans. No one is at risk from the minute amounts of mercury in any form of canned tuna."

Tuna is high in omega-3 fatty acids and is an excellent source of lean protein. It is also a good source of a variety of minerals and nutrients, including selenium, magnesium, potassium, niacin, folic acid, B1 and B6. The national dietary guidelines and organizations such as the American Heart Association advocate eating at least two servings of fish per week, and canned tuna is perhaps the most convenient way of having it.