According to figures from the Surgeon General’s office, only 17% of Americans are considered to have optimal mental health. Something is off, and scientists part of an emerging field called Nutritional Psychology are trying to sort out how much what we stuff in our mouths has to do with what’s going on in our heads.
 
So what should we be eating for optimal mental health?
 
Fish and Fatty Acids
 
While beets, blueberries, and walnuts have been linked to better brain function, some anthropologists suggest it was seafood that enabled humans to achieve crucial cognitive growth when our species faced extinction 150,000 to 200,000 years ago. During that time, a glacial period set in that made most of Africa inhospitable for the first modern man. With land-based sources of food scarce, the theory is that our ancestors likely turned to the coasts, subsisting on diets heavy in shellfish and other cold-water fish rich in omega-3 fatty acids.
 
This change to a seafood rich diet, some believe, may have been the catalyst of the great leap forward, the mysterious period during which humans developed language and art and began using more complicated tools.
 
Consumption of omega-3s, particularly docosahexaenoic acid (DHA), has been strongly linked with improved brain function. DHA appears to boost communication between neurons and promote the growth and survival of brain cells.
 
Plenty of research today touts the benefits of a diet rich in omega-3s. One study showed that teenagers at risk of schizophrenia saw their chances of developing psychosis drop after taking fish oil supplements. An earlier study from a Harvard psychiatrist showed omega-3s can help keep bipolar disease in remission. Traditional Mediterranean, Japanese and Scandinavian diets, which each prominently feature fish, have been shown to prevent depression and anxiety and slow cognitive decline.
 
Meanwhile, the so-called “Western” diet popular in the United States that is high in processed foods, sugars and refined carbohydrates may actually shrink the brain. One study showed that adults who consumed this diet for four years had a smaller left hippocampus and suffered higher rates of mood disorders.
 
Healthy Gut, Healthy Brain
 
A “gut feeling,” it turns out, is more than just a turn of phrase. The walls of the alimentary canal (the passageway for our food that runs from the esophagus through the intestines) is lined with neurons. This “second brain” not only controls digestion, it sends signals to the brain that impact our moods.
 
So what’s the science behind a happy gut leading to a happy mind? You might be familiar with serotonin, a neurotransmitter often associated with feelings of happiness. In fact, 95% of the serotonin in our bodies is located in the GI tract and its production is influenced by the bacteria in the gut.
 
New research shows that this gut microbiome also affects how genes are expressed —genes that regulate how nerve fibers are insulated and conduct impulses. Scientists see this as strong evidence that gut bacteria have a direct physical effect on the brain itself.
 
Besides probiotics, a heathy gut biome can be boosted by eating unprocessed, fermented foods, vegetables, nuts, seeds, whole grains and other sources of fiber. Heavily processed foods, on the other hand, actually kill off this good bacteria.

Eating Behavior

It’s not just what you eat, but who you eat it with that can boost well-being. Meals eaten at consistent times, for instance, can improve both eating habits and health outcomes. Eating meals as a family or group has many proven benefits: food is consumed more slowly, aiding digestion and a sense of being full. And, of course, shared meals strengthen social relationships.

It was like that for our ancestors. Anthropologist posit that as the population grew around shellfish beds, that’s what pushed humans to develop more complex forms of language to communicate with one another. Pass the oysters.