Risk lies in tuna surprise

August 19, 2002|By Jae Hong Lee

HERE ARE two quick questions: Did you know that young children and expecting mothers should eat no more than two 6-ounce cans of tuna a week? Did you know that regularly eating more might cause neurologic problems for babies and young children because of a toxin called methylmercury?

If you didn't know, you can blame the Food and Drug Administration (FDA), which has done a poor job of informing the public about this important health risk.

I can recall eating tuna all the time as a child. Whether it was tuna casserole in my school cafeteria or a tuna salad sandwich prepared by my mom on a warm summer day, tuna was a familiar -- and tasty -- part of my diet. There were probably times when I would eat tuna at least every other day.

Now we know that eating so much tuna -- and certain other types of fish -- may not be good for the young child whose brain and nervous system are still developing.

The National Academy of Sciences estimates that 60,000 newborns a year may be vulnerable to neurologic problems caused by methylmercury. Toxic methylmercury forms when naturally occurring mercury or mercury released in the air by industrial pollution interacts with bacteria in the water. Fish absorb it as they feed; some types accumulate high levels.

In January 2001, the FDA issued an advisory to women of childbearing age and young children, urging them to avoid eating four types of fish that usually have high levels of methylmercury: shark, swordfish, tilefish and king mackerel.

While seafood is an important part of a healthy diet, pregnant mothers who consume too much of the affected varieties can expose their unborn children to the toxin; nursing women can pass the toxin to their newborns through breast milk.

Because seafood is nutritious, the advisory suggested eating a variety of other fish from different sources, but limiting the total amount consumed to 12 ounces a week (that's roughly two to four average servings, if the average serving is about 2 ounces to 6 ounces).

Consumer groups were justifiably livid that the advisory made no specific mention of fresh or canned tuna. The FDA explained that methylmercury levels in tuna typically were lower than in the other four species.

While that's true, the explanation doesn't hold water: Ask yourself when your kids last ate shark or swordfish. Now, when was the last time they ate tuna? Tuna is the most popular fish in America. Nearly 1 billion pounds of tuna -- mostly canned -- are supplied to Americans each year. Just the sheer quantity consumed makes tuna a key source of potential methylmercury exposure. Discussing the risks of methylmercury without mentioning tuna is like discussing the risks of alcohol without mentioning beer.

After hearing numerous complaints, the FDA convened an advisory committee that met over three days in College Park in late July. The committee quickly agreed that the FDA should amend its advisory to include warnings about tuna and do more to get the word out about methylmercury hazard.

The committee also found the FDA's advisory, which was updated in March, to be vague and unclear about which age groups of young children are at risk. Also, most members of the committee admitted they didn't know whether they had ever eaten tilefish because they were not familiar with its more popular names -- golden bass and golden snapper.

I spoke briefly before the committee and senior officials of the FDA on the first day of the meeting. I urged them to specifically mention tuna in any future advisory and to place the advisories where most consumers will see them -- directly on packaging or cans. Dr. Sanford Miller, chairman of the committee, asked the FDA to explore "all avenues" for disseminating the information. These are just baby steps, but at least they are in the right direction.

The FDA is not required to follow the advice of the committee, but has said it will review the recommendations and develop an action plan by Oct. 1.

The tuna industry will lobby vigorously against any specific mention of tuna in a new advisory. Industry representatives point out that tuna and other fish are excellent sources of protein and omega-3 fatty acids. They claim that poor families that rely on inexpensive canned tuna might be frightened into avoiding fish altogether.

The industry is right about the health benefits of eating tuna and other fish. However, its wrong to believe that informing consumers about methylmercury would lead them to avoid fish completely.

After all, on the first day of the meeting, I ate a tuna croissant sandwich during lunch at the hotel's cafM-i. Tuna still appeals to my tastes.

Being informed of the risks of methylmercury didn't keep me from eating that tuna sandwich; it just kept me from ordering it again on the last two days of the meeting.

Dr. Jae Hong Lee wrote this article as the senior medical policy analyst at the nonprofit, nonpartisan National Center for Policy Research for Women & Families. He is now at the University of California, Berkeley School of Law.

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