Busting Mercury Myths

Would you take nutrition advice from a reality TV star? What about pregnancy tips from a boy band singer? Would you listen to a doctor who used your astrological sign to diagnose you? And yet, voices like these have put themselves at the front of a movement that produces misinformation about seafood and mercury, fueling a bona fide public health crisis.


Medical doctors like Dr. Oz, who recently took flack for that healthcare-via-the-zodiac segment, are especially concerning. Oz really ought to know better, but has unfortunately proven to be motivated more by clicks and ratings than sound science or the Hippocratic Oath.


It’s perhaps not surprising then that the latest bad advice on seafood and mercury comes from another doctor who has appeared on Dr. Oz’s show and found an audience among his followers. In a recent interview with Shape magazine, ER doctor Darria Gillespie dangerously recommending consumers limit their fish consumption to “no more than one or two servings a week.” But pregnant women need to eat more seafood than they currently do, not less. Statements like these cause expectant mothers to avoid fish all together, which can be harmful to their babies’ health. The FDA recommends that pregnant women eat at least two servings of a variety of seafood every week.


Avoiding Bad Mercury Advice


America’s daytime showman Dr. Oz made his career selling bad dietary advice to Americans. His publicity-seeking practices got so bad that in 2014 the British Medical Journal analyzed his work and concluded that more than half of his medical advice is either contradictory or lacks scientific evidence. Moreover, investigations by the New York Times and Chicago Tribune concluded that Oz provided a “chaotic bazaar of advice” and that much of Oz’s advice is at odds with the scientific community.


So Americans, and especially expectant mothers, should apply close scrutiny to advice offered by Oz or his acolytes. By helping spread misinformation to the public, these irresponsible “TV doctors” are implicating themselves in a major public health crisis.


Along with Dr. Oz and Dr. Darria, sites that may seem reliable like Medical Daily have also put out false information regarding mercury. The publication most recently listed tuna as a high mercury fish to avoid – along the lines of shark and tilefish, (which is simply false) – and quoted Consumer Reports’ debunked advice on tuna. It is important that pregnant women get the best advice for the health of their babies and ignore this type of scary click-bait.


Tuna and Mercury


Survey data shows that Americans are not eating enough seafood, causing them to miss out on important health benefits and leading to nearly 84,000 preventable deaths a year. The Dietary Guidelines for Americans, the USDA, and other leading authorities encourage people to eat fish because of its healthy amounts of B12 and D, iron, zinc, magnesium, phosphorous, selenium and beneficial omega-3s fatty acids called EPA and DHA. Tuna is an excellent and widely available option for tapping into this nutritional motherlode, high in protein and the omega-3s that play an essential role in brain and eye health.


Yet thanks in part to celebrity cranks and snake oil salesmen, many Americans believe tuna consumption should be limited over mercury fears. But the truth is that the average can of light or albacore tuna has mercury levels of 0.1 and 0.3 parts per million, substantially below the FDA’s safety level of 1.0ppm. That means that, according to the FDA’s Net Effects Report, the average person can safely eat tuna for breakfast, lunch, and dinner every day of the week. Maybe that’s why there has never been a case of mercury toxicity from normal consumption of commercial seafood recorded in any American medical journal.


Scientists reviewed an exhaustive body of research on mercury risk compared to the beneficial nutrients in fish, and strongly concluded that “consistent evidence shows that the health benefits from consuming a variety of seafood in the amounts recommended outweigh the health risks associated with methyl mercury” (USDA/HHS Dietary Guidelines for Americans). Despite this conclusive evidence that tuna’s mercury content is not dangerous, there are still misinformed or simply false statements out there that scare people away from eating tuna.


Pregnancy Advice


Perhaps the most harmful myths out there have to do with tuna consumption during pregnancy. Some poorly informed lifestyle gurus and pseudo experts even tell women they shouldn’t eat any fish during pregnancy – advice that isn’t only false, but dangerous. According to the USDA, pregnant women should have at least two to three servings of seafood each week to ensure their baby’s healthy development.


Because according to the same comprehensive FDA research on the matter, women could eat 164 ounces, or 54 standard three ounce cans, of canned light tuna every week without risk to their health. A recent study by Dr. Nicholas Ralston and Dr. Laura Raymond found that because of tuna’s selenium content, eating the fish has the ability to improve brain health. They conclude that any fish containing more selenium than mercury, such as tuna, has the ability to provide “nutritional benefits for health and development” for pregnant women and their fetuses.


In another recent study, scientists in Spain followed around 2,000 mothers and their children through pregnancy and the first five years of development. They found that by eating fish every week pregnant women were actually promoting fetal brain development and reducing their children’s’ risk of developing autism. Another long-term study showed that children whose mothers had reduced their seafood intake during pregnancy had children with a significantly lower IQ than those who did not.


The bottom line is that eating a variety of seafood, especially during pregnancy, is safe and healthy.