Fish's Fatty Acids May Undo Mercury-Related Brain Damage

Our modern-day need for fish could go way back.

BY JULIA WESTBROOK

Traditional recommendations have steered pregnant women away from fish for fear of mercury exposure, but it may be time to reevaluate these fears. The health benefits of eating fish not only eclipse the risks associated with mercury exposure, but may even counteract the brain damage, according to research published in The American Journal of Clinical Nutrition.

The researchers observed 1,265 mothers in the Republic of Seychelles, an archipelago in the Indian ocean where the population regularly eats a high-fish diet. They found that prenatal mercury exposure had no effect on measures of brain development at 20 months, including communication skills, behavior, and motor skills. Additionally, mothers who had higher levels of polyunsaturated fatty acids (PUFAs) from fish in their diet had children with higher scores.  

"These findings show no overall association between prenatal exposure to mercury through fish consumption and neurodevelopmental outcomes," said study co-author Edwin van Wijngaarden, PhD, associate professor in the University of Rochester's Department of Public Health Sciences. "It is also becoming increasingly clear that the benefits of fish consumption may outweigh, or even mask, any potentially adverse effects of mercury."

The researchers point out that fish fatty acids have antiinflammatory properties that may counteract mercury's inflammation.

The importance of fish for brain development cannot be understated. In fact, some credit fish for evolving our species into the cognitive beings we are today. "A few anthropologists are considering a new hypothesis that omega-3 fatty acids may have played a prominent role in the development of the modern advanced human brain," says Oceana CEO Andy Sharpless, author of The Perfect Protein: The Fish Lover's Guide to Saving the Oceans and Feeding the World.

The theory goes like this, Sharpless explains: The human brain evolved to be different than other primate brains because the omega-3s in fish, the necessary key for enhanced development, existed on the shores, where human decedents lived, not in the forests or savannahs, where other primates lived.

There is plenty of evidence that supports this theory, such as 90,000-year-old harpoons near Lake Edward in Africa and fossils that show that people ate oysters 100,000 years ago.

"Perhaps the greatest argument for the legitimacy of the shore-based scenario of human evolution is that we may still be in it," adds Sharpless. "Rivers, lakes, seas, and oceans have dominated culture as sources of food, transportation, and mythology. We still thrive on a diet rich in the essential omega-3 fatty acids found in seafood, relying on it for basic health and development, and when we've strayed from it, we've paid for it with our health."

Given fish's important role for brain development (that could possibly span back and explain human's unprecedented brain power), the idea that people, especially pregnant women, should avoid all fish is absurd. A smarter move is to avoid fish notoriously high in mercury and focus on the cleaner ones. Skip the Atlantic bluefin tuna, Chilean sea bass, and shark and opt for U.S. or British Columbia troll- or pole-caught albacore tuna, mussels, and wild salmon from Alaska. And to be sure your fish is being caught sustainably, use the Seafood Watch app by theMontery Bay Aquarium to take a peek at how your fish was caught before you buy

If fish is out of the question for you, good news: Omega-3s in flax has been shown to boost heart health similarly to fish-based omegas.

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