Study Raises New Concerns About Mercury in Tuna A new study from Consumer Reports magazine recommends that pregnant women avoid eating canned tuna. It was previously believed that light tuna had lower mercury content. Urvashi Rangan, a toxicologist for the study, talks to Melissa Block about the findings.

Study Raises New Concerns About Mercury in Tuna

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Pregnant women should never eat any canned tuna. That's a new recommendation from Consumer Reports Magazine. That restrictive advice is drawing criticism from both the FDA and the tuna industry, who say the magazine's position is extreme. Urvashi Rangan is a senior scientist with Consumer Reports. She was a toxicologist for their study. Dr. Rangan, thanks for being with us.

Dr. URVASHI RANGAN (Consumer Reports Senior Scientist): Thank you. It's my pleasure.

BLOCK: And let's talk first about what the concern is with pregnant women and tuna. It's all about mercury content.

Dr. RANGAN: That's right. It's all about mercury and mercury exposure for the fetus. Mercury is a neuro-toxicant and can affect the developing nervous system. And considering the fetus is just developing its nervous system for the first time, it's particularly vulnerable.

BLOCK: Well, we've been hearing about the possible health effects of tuna in pregnancy for some time. The FDA has recommended before that pregnant women limit their intake of tuna, especially albacore tuna. But before, they said that canned light tuna was low in mercury, and you're saying it's not low enough.

Dr. RANGAN: That's right. We took a second look at those FDA numbers, and while the FDA is correct, albacore on average tends to have higher levels than the light tunas. When we took a closer look at the data and looked at individual sample tests, what we found is that while the averages are as the FDA reports, the spread and variability and the levels of mercury in the tuna cans and in the samples actually varies quite widely. In six percent of the samples, in fact - in the light samples - those levels actually met or exceeded the average levels of albacore tuna.

BLOCK: Six percent?

Dr. RANGAN: Six percent. And what that says to us is it's simply too much to know what you're getting in any given can of tuna when you buy it in the store. You may be getting an average level that the FDA quotes, but you may, in fact, be getting even higher levels. And, as a result, if you're in an especially susceptible population like pregnant women, you should take every step you can to avoid exposure to mercury and additional exposure, and to reduce any kind of risk to the fetus.

BLOCK: So you're saying any risk, basically, is too great.

Dr. RANGAN: Any risk is too great, especially when you're talking about an avoidable risk. Pregnant women and everyone else looks to fish to get Omega 3 fatty acids, for example, as a large nutritional benefit of eating fish. But there are other alternatives to tuna where you can get those Omega 3 fatty acids, while also avoiding the large mercury exposure.

BLOCK: And what would some of those alternatives be?

Dr. RANGAN: Some of those would be shrimp, tilapia, wild cod salmon. Those are examples of various types of fish which are low in mercury that also are fairly high in omega 3 fatty acids.

BLOCK: Let me ask you about some of the reaction to your study. The FDA is saying that the average mercury level in canned light tuna is low, and they say that there are no new warnings or labeling that are needed.

Dr. RANGAN: It's true. The FDA seems to be taking a more loose approach to public health precaution in this case. And it's somewhat disappointing, especially in light of the fact that in 2004, the Environmental Protection Agency - based on some data from the Center for Disease Control - estimated that one in six women are already at their maximum mercury levels in their blood when they get pregnant, which means that people aren't starting at a level of zero. People actually have a fair amount of mercury in their systems already.

BLOCK: What about this comment from Louis Sullivan, who is a former secretary of health and human services, and he's now a consultant for the Tuna Foundation. He told the Chicago Tribune - which has done a lot of reporting on this issue - he said, I don't know of any science that supports what Consumer Reports is saying. For all we know, they could be relying on high school science students to come up with this.

(Soundbite of laughter)

Dr. RANGAN: Yeah, well, Louis Sullivan is paid by the tuna industry, which obviously has a vested interest in selling tuna. We're certainly not telling people to stop eating tuna. What we're doing is trying to issue a warning to pregnant women who are particularly vulnerable to the toxic effects of mercury.

BLOCK: Dr. Rangan, thanks very much.

Dr. RANGAN: Thank you so much.

BLOCK: Urvashi Rangan is a senior scientist with Consumer Reports. You can find a link to the magazine's article, and both their and the FDA's recommendations on eating tuna as well as other fish on our Web site,

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