Consumer Reports misses mark on mercury

Consumer Reports is a U.S. magazine best known for product reviews and brand comparisons, but most people don’t regard the magazine as an authority when it comes to food safety and health.

Sadly, the latest article from the magazine purporting to offer sound advice to pregnant women regarding mercury in seafood does little to improve its reputation. The article repeats rhetoric from a website with suspect motives, ignores scientific data on mercury in seafood and cherry-picks U.S. Food and Drug Administration (FDA) data.

The U.S.-based National Fisheries Institute (NFI) was quick to retort, saying the article “flies in the face of more than a decade of independent, peer-reviewed, published science that resulted in the FDA updating its advice to pregnant women to eat more fish, including canned tuna, to realize the health benefits for baby and mother.”

The Consumer Reports article comes on the heels of an announcement by FDA in June that it plans to revise its guidelines for public health regarding seafood in the American diet.

The publication began with a study of FDA data on mercury levels in seafood. A Consumer Reports spokesman wasn’t available to explain its research, but in combing through the FDA’s website and contacting the FDA for comment, it appears the magazine is using this chart as a starting point. It lists the maximum amount of mercury FDA scientists found in various amounts of seafood tested over a 20-year period, from 1990 to 2010.

From there, Consumer Reports scientists appear to have calculated, based on established toxicity levels, just how much of varying species of seafood pregnant women should be eating, much as the FDA has done prior to issuing its recommendations. The magazine’s authors admitted in the article that they agreed on almost all points with the FDA’s recommendations. So far so good.

Then they got to canned tuna, specifically albacore and skipjack, or “light” tuna. These two species make up the majority of the common commercially available canned tuna in the United States. Suddenly, the magazine differed with the FDA. A graph on page 2 of the article indicates that a child weighing about 55 pounds should eat less than a five-ounce can per week of light tuna. For albacore, only someone weighing 154 pounds could get away with eating that much per week safely. The article also directly contradicts current FDA advisories that a woman of child-bearing age may eat as much as 12 ounces of fish per week. As the magazine’s authors wrote regarding canned tuna, “We don’t think pregnant women should eat any.”

Why the discrepancy? The article disputes the FDA’s standard for how much mercury is too much, citing a former FDA senior risk assessor, but goes on to say “even using (the government’s) current levels” means no child weighing up to 48 pounds should eat more than 1.5 ounces per week. The article also cites FDA data that shows an occasional spike in the amount of mercury in the average can, up to double the average.

That sounds legitimate until one considers there’s more data that didn’t make it into the Consumer Reports article. In a paper on the subject dated May 2014, the FDA presented an exhaustive analysis of the neurological development benefits of eating commercial fish.

One chart compared the benefits of improved brain function from eating seafood to the potential damage done by mercury from eating too much. The chart even takes into account the spikes by assuming all fish listed had 20 percent more mercury content than average. The results show that pregnant women can eat as much as 56 ounces of canned albacore tuna per week before the effects “become adverse,” meaning the danger of mercury cancels out the benefits of eating seafood. For light canned tuna, FDA indicates a pregnant woman can eat as much as 164 ounces before mercury finally becomes a problem. That’s more than 32 five-ounce cans of tuna per week. To say the FDA’s opinion differs from Consumer Reports is an understatement.

The FDA’s Siobhan DeLancey said of the Consumer Reports article, “It focuses exclusively on the mercury levels in fish without considering the known positive nutritional benefits attributed to fish. As a result, the methodology employed by Consumer Reports overestimates the negative effects and overlooks the strong body of scientific evidence published in the last decade.”

There’s another critical factor in the mercury-in-seafood debate that is absent from the article — the role of the chemical selenium in the contamination process. Selenium exists in every functioning human brain. It has to, as humans, like most mammals, need oxygen to survive, but reactions with oxygen create by-products that have a corrosive effect on matter. Oxidation is what causes rust in metal, and makes an apple turn brown after it’s left on the kitchen counter for too long. Without selenium to stop that corrosive reaction, the same thing happens to our brains, according to Nick Ralston, a scientist at the University of North Dakota who has been researching this issue for years.

“It is literally the same process,” he said.

The danger of mercury, he said, is that it chemically bonds with selenium, so if it’s in a person’s bloodstream and flows into the human brain, it will bind with the selenium, which leaves the brain vulnerable to the irreversible damage.

But seafood contains selenium, too, a fact that goes largely ignored. Ralston’s research — which has been funded by the U.S. Environmental Protection Agency and the National Oceanic and Atmospheric Administration, and is peer-reviewed — shows that in many fish, including most common tuna species such as albacore and skipjack, there is more than enough selenium present in the fish to offset or supplement selenium losses caused by the mercury. In other words, his research has found that the same tuna Consumer Reports declares to be unfit for pregnant women is actually perfectly safe to eat.

“We haven’t found a tuna yet that’s a problem,” he said.

Why did Consumer Reports focus largely on the negative benefits, and not the positives? One answer may lie in the site's featuring of the “Mercury calculator,” an online form that claims to be able to tell consumers how much of a particular species they can safely eat in a week based on nothing more than body weight.

This form is provided by the Turtle Island Restoration Network, a nonprofit conservation group that has a page titled “Got Mercury?” on its site. The page offers six different fact sheets to click on. As of Monday, only one actually works, and it tells us little more than what Consumer Reports does about the FDA’s data on mercury. Turtle Island’s mercury calculator has long been criticized as an overly simplistic tool designed by an NGO to scare people into not buying tuna, so fewer people will fish for it, and accidentally catch fewer sea turtles in the process.

Consumer Reports should know better than to link to an NGO with such a bent against tuna fishing, especially as a supplement to an article that is supposed to be informing public health. The FDA’s proposed new guidelines are designed to encourage people to consider the great benefits of seafood in a healthy diet, not just the potential dangers. The FDA gets that both sides must be weighed evenly to make proper decisions about what to eat. With any luck, the seafood-consuming public will approach the subject with more of a balanced eye toward facts than Consumer Reports does.


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