Marc Joseph Nutrition - Blog

These were a few of the headlines after the recent release of two studies examining the health benefits and risks of eating fish:

Seafood benefits found to outweigh risks (Boston Globe)

Eat more fish, study urges, despite toxin risk (Reuters)

Seafood not your health foe, studies say (SJ Mercury News)

The first study, a meta-review* completed by researchers at the Harvard School of Public Health and published in the Journal of the American Medical Association, boldly suggested that regular fish consumption could reduce the risk of heart attack death by 36 percent and the overall risk of death by 17 percent.

(* A meta-review is a review of the existing body of research. Perhaps the Harvard meta-review excluded studies like this one, “Mercury in fish poses heart risk for middle-aged men“?)

The second study, a report completed by the Institute of Medicine (IOM), was more balanced in its review of the research. It concluded only that the regular consumption of fatty fish may reduce the risk of heart disease, while “contaminants that may be present in seafood may pose a risk to some especially susceptible groups of people.”

A More Balanced View

Just reading the headlines, one could easily draw the conclusion that concerns about toxins in seafood are overblown and that there’s really nothing to be concerned about unless you’re a pregnant woman, a prospective mother, or a small child. Fortunately, the NY Times presented a much more balanced perspective in their coverage:

The Harvard study, to be published in the Journal of the American Medical Association today, said the benefits of eating fish high in omega-3’s strongly outweighs risks from contaminants like PCB’s and dioxin found in high concentrations in fish like farmed salmon. Calling those risks “greatly exaggerated,” Dr. Darius Mozaffarian, one of the two authors, said, “Seafood is likely the single most important food one can consume for good health.”

Dr. Marion Nestle, a professor of nutrition, food studies, and public health at New York University, who described the “very sunny Harvard study” as “astonishing,” remains unconvinced. “The report’s conclusion that the risk of death can be reduced by 36 percent is just stunning,” she said. “It would indeed make eating fish the single most important decision you can make for your health. But those of us who have been in nutrition for a long time have seen miracle foods come and go: vitamin E for heart disease, beta carotene to prevent cancer; now it’s fish.”…

…The report from the Institute of Medicine tells the government that much more research is needed. Dr. Malden C. Nesheim, chairman of the institute’s committee and a provost emeritus at Cornell, said, “We are quite cautious because the studies we looked at are not controlled for all the variables, and we can’t distinguish between the effects from omega-3’s or replacement of other foods in the diet.”

The NY Times reporter then exposed some of the behind-the-scenes political maneuvering:

The National Oceanic & Atmospheric Administration [NOAA] had requested the institute’s report because it said consumers were confused about how much and what kind of fish they should eat. The two studies, which conflict in important aspects, seem unlikely to provide much clarity. “The high degree of certainty in one report and the extreme caution in the other,” said Rebecca Goldberg, a senior scientist with Environmental Defense, an advocacy group, “will make people more confused than ever.”

To the surprise of Institute of Medicine officials, NOAA sponsored the hastily called press conference at which the Harvard report was released, even though that study conflicted with the one prepared by the institute. “We’re just trying to make consumers feel good*,” said William T. Hogarth, assistant administrator for fisheries of the National Marine Fisheries Service*, part of NOAA.

[* emphasis added]

Major environmental and groups noticed the inconsistencies as well:

Both reports have come under criticism from environmental groups and from the Consumers Union. “In addition to being concerned about the failure of the JAMA and I.O.M. reports to address the risks of mercury in tuna,” said the consumer organization, “we are also concerned that both reports dismiss concerns about PCB’s in most fish.”

“These reports are urging Americans to eat more seafood as if it were a crisis,” Dr. Goldberg said. “According to NOAA’s own statistics, per capita consumption of seafood has risen from 14.8 pounds in 2001 to 16.6 pounds in 2004.”

Jane Houlihan, the research director of the Environmental Working Group, another advocacy group, said, “The Harvard study reads like an advertisement for the seafood industry.”…

…“Once again pregnant women are being told it’s O.K. to eat tuna,” Ms. Houlihan said. “The reality is, 90 percent of women would exceed government’s level for a safe dose of mercury if they ate six ounces of albacore tuna every week as the F.D.A., E.P.A and now I.O.M. recommend.”

What to Do

Omega-3 fats found in fish clearly are beneficial for heart, brain, and immune system health. There’s a great overview of those benefits discussed in this article, “Omega-3 Fatty Acids: Vital to a longer, healthier life.” And the truth is that the majority of people do not take in adequate amounts of these healthy fats.

Unfortunately, though, many fish are contaminated with toxins such as mercury. Do yourself and your family a favor. Use a simple online calculator like this one to help plan safe seafood consumption.

(While you’re there, ask yourself why government agencies responsible for advising consumers on safe fish consumption haven’t put together such easy-to-use tools? The IOM, in fact, recommended the creation of such tools in their report.)

Better yet, to ensure adequate Omega-3 fat intake, include regular consumption of fish oils that have been tested to be free of contaminants such as heavy metals, PCBs, etc. There’s a good list of safe products here.

This entry was posted on Tuesday, November 7th, 2006 at 10:20 pm and is filed under Mercury, Regulation, Seafood, Essential Fatty Acids - EFAs. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.