Researcher triggers storm over study on tilapia

When it comes to medical studies, consumer spending and corporate profits can be a combustible mix for scientists and researchers.

That reality has become clear to Floyd "Ski" Chilton, a professor of physiology and pharmacology and the director of the Wake Forest Center for Botanical Lipids.

It's been about three weeks since Chilton and the Wake Forest University School of Medicine released a report advising people with inflammatory issues to reduce or eliminate their consumption of tilapia, a popular, lower-cost fish.

Chilton said last week that he's been stunned by the aggressive "sound-bite criticism" from the National Fisheries Institute, an industry trade group. Other critics include a colleague at the medical school.

"I've published 110 medical articles, and I am incredibly surprised by the tone of the response by one or two organizations to a study in a very reputable, peer-reviewed journal," Chilton said.

The study appeared in this month's issue of Journal of the American Dietetic Association, which also featured a report that offered a mixed review of the Wake findings. Chilton will have the opportunity to respond to the critical report in a coming issue of the journal.

Dr. William Applegate, the dean of Wake Forest University School of Medicine, said that criticism, including from colleagues, is an inherent, and sometimes helpful, part of the advancement of science.

"The higher the financial stake involved in a study, the greater the level of industry criticism tends to be generated," Applegate said.

The fisheries institute is targeting the Wake study because of its potential for affecting sales of tilapia, institute officials said.

In its criticism of the Wake study, the fisheries institute particularly emphasized this statement in a July 17 press release about the study: "The types of fats in popular seafood have led to reports that bacon, hamburgers and doughnuts are a better choice than certain fish."

The trouble with the institute's position is that the Wake study doesn't make that claim.

What the Wake study does say is that "Tilapia has higher levels of potentially detrimental long-chain omega-6 fatty acids than 80-percent-lean hamburger, doughnuts and even pork bacon."

"All other nutritional content aside, the inflammatory potential of hamburger and pork bacon is lower than the average serving of farmed tilapia."

The study found that farm-raised tilapia -- the fifth most popular fish consumed in the United States -- has very low levels of beneficial omega-3 fatty acids, primarily because the fish eat inexpensive corn-based feed.

"Perhaps worse, it contains very high levels of omega-6 fatty acids," researchers said.

The combination "could be a potentially dangerous food source for some patients with heart disease, arthritis, asthma and other allergic and auto-immune diseases that are particularly vulnerable to an 'exaggerated inflammatory response.'"

"They have sound-bited the study, taking things out of context to take the study in a different direction than the science," Chilton said. "There is a vulnerable population not enhancing the quality of their health with the best source of omega-3 fatty acids, and they deserve the knowledge."

Chilton said that consumers should still eat at least two servings of fish a week but focus more on salmon, mackerel, albacore tuna and shrimp for better omega-3 benefits. He also recommended taking fish-oil supplements.

E-mail Richard Craver at rcraver(at)wsjournal.com.

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