Your Brain On Junk Food: 'Making Us Crazy' — But Might Fish Help?

An urban planner and a biochemist walk into a seafood restaurant.

Okay, that joke’s going nowhere, but last week an urban planner and a biochemist did walk into a classroom at MIT. In a talk titled “Junk Food and the Modern Mind,” the unusual duo explained to a room full of people how seafood’s effects on the human brain could bridge their seemingly disparate fields.

The urban planner was Lynn Todman, a visiting scholar at MIT. Todman has spent the past nine years working to improve mental health and reduce violence among residents of some of Chicago’s roughest neighborhoods.

(Wikimedia Commons)
(Wikimedia Commons)

“Now, I’ve been doing community based work for a long time, and I know that residents often understand social realities long before we do in the academy, and even though their understanding might be shaped by a series of anecdotes strung together to suggest a trend or pattern, I attribute very real meaning to what residents say about their communities and the observations about the world that they live in,” she said.

Enter Capt. Joe Hibbeln, the biochemist.

Hibbeln, who is also a psychiatrist, works at the National Institutes of Health as a nutritional neuroscientist and is one of the world’s leading experts on the role of fats in brain development.

His claim: a diet rich in omega-3 fatty acids and low in omega-6 fatty acids can make people happier and less aggressive.

Consider, Hibbeln said, that brains are mostly made of fat and that during early development, until around age 18, they hoard omega-3 fatty acids. In one experiment, he said, scientists took neuron cultures and fed high omega-3 diets to one group and low omega-3 diets to another. Neurons in the first group had twice as many synapses, i.e. twice the complexity, as those in the latter group.

Lucky for New Englanders, fish is a rich source of omega-3s.

“There’s a lot of fish in Boston. I always found it was a remarkable conjuncture between brainy people and Boston and the levels of cod that are eaten here,” Hibbeln joked.

Don’t worry, vegetarians. There are other sources of omega-3s like olive oil.

As for happiness, Hibbeln cited a study on piglets who were fed either high omega-3 or low omega-3 diets for 18 days. Those in the first group had nearly twice as much serotonin and twice as much dopamine in their systems.

In humans, Hibbeln said, there have been 42 studies showing that high omega-3 intake can help those with major depression.

“I can tell you with great confidence that yes, omega-3 fatty acids in comparison to a placebo have a larger effect size and are more effective than most pharmaceutical antidepressants,” he said.

What’s more, a study that Hibbeln conducted on kids between the ages of 8 and 16 showed reductions in delinquency, depressive and anxiety disorders and unemotional behavior among those on high omega-3 diets.

A plot of seafood consumption per country per year vs. homicide rate showed a 30-fold increase in homicides in the countries with lowest seafood consumption compared to those with highest seafood consumption. Bulgaria was on the high homicide end and Japan on the low homicide end. This trend, Hibbeln made sure to point out, was strictly observational.

The problem in this country is that the U.S. food system is full of omega-6 fatty acids, which compete with omega-3s. For that, Hibbeln said, soybean oil is to blame. The rise of soybean oil from a nonexistent part of our diet to about 10 percent of our caloric intake, he said, represents the largest shift in the human diet, even larger than going from hunting and gathering to agriculture, and it’s “flooded everybody’s brains with omega 6 fatty acids.”

In food deserts like the Chicago neighborhoods where Todman worked, people have little choice but to eat high omega-6, low omega-3 diets.

It’s too soon to draw a direct link between diet and aggressive behavior, but Hibbeln, who has been studying these fats for more than two decades, and Todman, who is newly intrigued by the role of diet in inner city violence, plan to continue this line of inquiry.

In a vote of confidence, the U.S. Army has given Hibbeln $10 million to conduct a study on how diet can lower the high rate of suicide among veterans. Results from that study, called BRAVO, should be available in 3.5 to 4 years, Hibbeln said, but an early pilot study in Ireland showed a 40 percent reduction in suicidal thoughts among those on a high omega-3 diet.


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