How Much Fish Should You Eat to Benefit Your Brain?

A weekly newsletter featuring the biggest ideas from the smartest people

A new study confirms that eating fish once a week can help increase the size of your brain, especially areas associated with memory and cognition. But the potency of the omega-3 vitamin, long thought to be the source of this beneficial effect, is now in doubt. Conducted at UCLA and published in the American Journal of Preventative Medicine, the study analyzed data from 260 cognitively normal people, average age 78, who had answered diet questionnaires, had their blood levels of omega-3 fatty acids measured, and their brains scanned.

“The researchers found that weekly consumption of baked or broiled fish — but not fried fish — was associated with larger gray matter…including areas where amyloid plaques, a sign of Alzheimer’s disease, first appear. … The results were the same regardless of omega-3 levels, suggesting that omega-3s were not the determining factor.”

Eating fish more than once a week conferred no extra health benefits on those followed by the study. The lead author, Dr. Cyrus A. Raji, said that eating fish once a week and maintaining a healthy lifestyle were enough to realize all the potential cerebral benefits. “Physical activity, weight control, and so on — these factors influence the brain more than any supplement or any medicine,” he said. “It’s much more in our control than we thought.”