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Seafood Trade-offs

We’ve been swimming in all the news about seafood this week. In a preemptive strike, before anything was even published, the Pundit started getting announcements designed to discredit a big report expected to come out on the risks and benefits of eating seafood. We viewed these types of announcements as immediately suspect because they consisted of ad hominon attacks, rather than substantive objections to either the report or to the work of the people on the panel.

You got things like this:

“…the panel appears to be biased toward nutritional benefits of fish, as evidenced by its makeup. The 13-member panel includes several members of the Institute of Food Technologists, a group whose board is heavily dominated by industry representatives. Only one member is recognized as a practitioner in the field of mercury toxicity.

That member, Dr. David Bellinger of Harvard University, was an author of a report last year funded largely by the U.S. tuna industry. While the report itself clearly showed that women and children should avoid high mercury fish and consume low mercury fish, this finding was ignored in favor of a sensationalized media strategy suggesting only that avoiding fish could do more harm than good. According to CSPI, Bellinger’s conflict of interest “violated any reasonable interpretation of the National Academy of Science/Institute of Medicine’s conflict of interest rules.”

On its face these objections seem frivolous. The Institute of Food Technologists is just a scientific society with no position on seafood, and even if it had such a position, the board members are researchers, professors, scientists, etc., who are not obligated to agree with all IFT policies.

The comments about Dr. David Bellinger are, well, a red herring — he did a study funded by tuna people — and that means, what, that he sold his soul to Chicken of the Sea? They literally can’t even find a quote from the report that they want to indict; instead they attack a “sensationalized media strategy,” which, even assuming this charge is correct, means nothing. The author of a report isn’t responsible for the fact that interests pluck out their favorite parts of a report to emphasize in their public relations efforts.

The Institute of Food Technologists apparently agreed with me as they shot out a press release of their own. Among the highlights:

“Contrary to a claim made earlier today, the Institute of Food Technologists does not have several of its members serving on an Institute of Medicine panel. The two IFT members serving the 13-member panel are employed as professors at flagship research universities in Nevada and Florida. Each is respected for his scientific knowledge and demonstrates integrity to science.


“To further clarify, the IFT Executive Committee is comprised of individual members, each selected by a worldwide vote of IFT’s membership. Like IFT, this committee is comprised of individuals who are — or have been — employed in academia, government and industry. Their service to IFT as volunteer leaders is irrespective of their employment. Any description otherwise is not factual. IFT had no influence on the IOM panel’s appointment.

Finally, the Institute of Medicine, which is part of The National Academies that advise the nation on science, engineering and medicine, came out with its report. You can read it here. The name of the report is Seafood Choices: Balancing Benefits and Risks and, from its very name, we knew good stuff was included.

As has been completely lost in, for example, the recent spinach crisis, most things in life involve both benefits and risks, and we have a significant problem when we try and assign words such as “safe” to products.

In addition, the report acknowledges what so many advocates don’t like to acknowledge — imperfect knowledge. In a press release announcing the report, such humility was clearly in evidence:

Much of the evidence on seafood’s health benefits and risks is preliminary or insufficient, the committee found. Reliable data on the distribution of some contaminants is lacking, and there is little evidence on how beneficial effects of seafood might counteract some of the risks from contaminants. Evidence suggesting that people who have suffered heart attacks can reduce their risk of future heart attacks by eating seafood is weaker than previously thought, the committee concluded. It is also not clear whether consuming seafood might reduce people’s risks for diabetes, cancer, Alzheimer’s disease, or other ailments.

Even when there is some evidence, the actual causal link is typically a mystery:

However, the committee confirmed that eating fish and shellfish may reduce people’s overall risk for developing heart disease. It is not certain whether this is because substituting the lean protein of seafood for fatty cuts of meat reduces consumers’ intake of saturated fat and cholesterol or because of the protective effects of omega-3 fatty acids, which are found in relatively high amounts in many fish species. Americans generally consume too much saturated fat and cholesterol and too little of “good fats” such as the omega-3 fatty acids EPA and DHA in fish.

There are risks to seafood:

Seafood is the major source of human exposure to methylmercury, a contaminant that accumulates in the muscle of animals over time. Because evidence suggests that methylmercury can disrupt neurodevelopment in the fetus, the report supports current recommendations that women who are pregnant or wish to become pregnant avoid consumption of lean, predatory fish such as swordfish, shark, king mackerel, and tilefish, and limit their consumption of albacore, or “white,” tuna. Other potential risks associated with seafood are exposure to persistent organic pollutants, such as dioxin and PCBs — though there is not clear evidence on the adverse effects associated with these compounds — and microbial infections, which are contracted mainly through the consumption of raw or undercooked fish and shellfish.

And certain subgroups of the population need to take special care:


  1. Females who are or may become pregnant or who are breast-feeding:

    • May benefit from consuming seafood, especially those with relatively higher concentrations of EPA and DHA.
    • A reasonable intake would be two 3-ounce (cooked) servings, but they can safely consume 12 ounces per week.
    • Can consume up to 6 ounces of white (albacore) tuna per week.
    • Should avoid large predatory fish such as shark, swordfish, tilefish, or king mackerel
  2. Children up to 12 years of age:

    • May benefit from consuming seafood, especially those with relatively higher concentrations of EPA and DHA.
    • A reasonable intake would be two 3-ounce (cooked) or age-appropriate servings, but they can safely consume 12 ounces per week
    • Can consume up to 6 ounces of white (albacore) tuna per week.
    • Should avoid large predatory fish such as shark, swordfish, tilefish, or king mackerel.
  3. Healthy adolescent and adult males and females (who will not become pregnant):

    • May reduce their risk for future cardiovascular disease by consuming seafood regularly (as suggested by the Dietary Guidelines for Americans).
    • Who consume more than two servings a week should ensure that they select a variety of seafood to reduce the risk for exposure to contaminants from a single source.
  4. Adult males and females who are at risk of coronary heart disease:

    • May reduce their risk for cardiovascular disease by consuming seafood regularly.
    • Although supporting evidence is limited, there may be additional benefits from including seafood selections with high levels of EPA and DHA.
    • Who consume more than two servings a week should ensure that they select a variety of seafood to reduce the risk for exposure to contaminants from a single source.

But, in balance:

The report supports current dietary guidelines and seafood advisories. However, the committee’s interpretation of the risks and benefits differs in that it consolidates information on both risks and benefits for sensitive population groups and addresses all segments of the population. And it does not support giving those with a history of heart disease advice different from that given to the general population.

Most people can gain nutritional benefits from seafood while minimizing their risk of exposure to contaminants by selecting fish and shellfish in amounts that fall within current dietary guidelines, the report says. Because seafood supplies and cultivation practices change constantly, it would be difficult for federal agencies to develop a list of “good fish” and “bad fish” that would not become obsolete in a short time. However, the benefits and risks for broad categories of seafood are relatively consistent…”

The seafood industry believes that fish consumption is being unnecessarily reduced as most consumers are not anywhere near their maximum consumption level but get scared away by confusing publicity.

And, indeed, another new study, this one out of Harvard and not considered in the Institute of Medicine report, pointed to the danger of this phenomenon. You can read an article that references it here. The article explains:

“The average person can consume more fish than they do,” says Susan M. Krebs-Smith, PhD, a panelist who is chief of the risk factor monitoring and methods branch of the National Cancer Institute.”


“…a new Harvard University study, published in this week’s issue of The Journal of the American Medical Association, concluding that regularly eating salmon and other fish high in omega-3 fatty acids can cut risk of death from heart disease by more than a third.

The study, based on a review of previous research, also concludes that the benefits of eating salmon on the heart greatly outweigh what some studies have pegged as an increased cancer risk owing to dioxin contamination found in farm-raised fish.”

But the industry may not see the bump in consumption it would like from this report because some people are not as worried about the health of people as they are focused on the health of the world fisheries:

“What we’re finding is that the fish that are highest in contaminants such as sharks, bluefin tuna and swordfish also tend to be unsustainable under current management practices,” said George Leonard, the science manager for the Monterey Bay Aquarium’s Seafood Watch Program.

The aquarium has been a leader in promoting commercial fisheries that don’t deplete a fish population beyond its ability to recover. The Seafood Watch Program includes an extensive list of marine species ranked according to sustainability. The list also notes health risks associated with specific species.

Under the aquarium’s criteria, several species are strongly discouraged. Patagonian toothfish — more popularly known as Chilean sea bass, a favorite of upscale restaurants — is chief among them.

“The fishery is in steep decline, and about half of the catch is illegal,” Leonard said.

But the savior of the fisheries may be that unexpected ally of the environmentalists, Wal-Mart:

“Most recently, Wal-Mart announced they will (identify the) source of all their seafood in three to five years,” Leonard said. “That’s huge. We’re at the tipping point. This is going to proliferate throughout the business community.”

You can learn more about the Wal-Mart initiative here.

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