Fish, Nutrition & Cognitive Function

Evidence is so strong that the World Health Organization developed guidance for dietary approaches to protect cognitive function. They too recommend Mediterranean, DASH, and MIND diets (Risk Reduction of Cognitive Decline and Dementia. WHO Guidelines, 2019). A Mediterranean diet “may be recommended to adults with normal cognition and mild cognitive impairment to reduce the risk of cognitive decline and/or dementia,” advises WHO.

Can diet impact cognitive health and the risk for Alzheimer’s disease? Yes, conclude Puri and colleagues in their review on nutrition and cognitive health. They say that recognizing the role of diet in cognitive health “will open up the use of new approaches for prevention, treatment or management of age-related disorders.” Specifically, they note, “Mediterranean, Nordic, DASH, and MIND diets are linked to a lower risk of cognitive decline and dementia.” 

Fish common in dietary advice

Frequent consumption of fatty fish such as salmon or tuna is common to these eating plans. Harvard Health explains, “Fatty fish are abundant sources of omega-3 fatty acids, healthy unsaturated fats that have been linked to lower blood levels of beta-amyloid—the protein that forms damaging clumps in the brains of people with Alzheimer’s disease. Try to eat fish at least twice a week…”

Why are omega-s important? High intake is linked to “a reduced risk of cognitive decline, Alzheimer’s disease, and dementia,” says the National Institutes of Health. “Omega-3s might protect cognitive function by helping to maintain neuronal function and cell membrane integrity,” they explain. 

Eating fish is good advice even for people who have healthy brain functioning. The WHO guidelines point out, “Higher fish consumption has been linked to lower memory decline among healthy participants in many studies.”

What is the MIND diet?

This dietary model was developed by Martha Clare Morris, a nutritional epidemiologist at Rush University Medical Center in Chicago through its Memory and Aging Project. The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet draws on scientific evidence to promote foods that protect brain health. Ongoing research has verified a positive impact on cognitive performance.

What’s in the MIND diet? Liberal intake from 10 food groups:

• Leafy greens 
• Other vegetables 
• Berries 
• Whole grains 
• Fish 
• Poultry 
• Beans 
• Nuts 
• Extra virgin olive oil in place of butter or other fats

The plain limits red meat, full-fat dairy products, and sweets. As the name implies, it is very similar to the Mediterranean Diet and the DASH diet, which was developed to prevent hypertension. 

Prevent or slow dementia

The MIND diet could “directly prevent the onset or slow the progression of dementia,” according to experts at Harvard Health. The eating plan “contains foods rich in certain vitamins, carotenoids, and flavonoids that are believed to protect the brain by reducing oxidative stress and inflammation,” they explain. Emerging research  findings are positive.. For example, they note, “Researchers found a 53% lower rate of Alzheimer’s disease for those with the highest MIND scores.”

Mediterranean and MIND diets both use a plant-forward approach. Drilling down, researchers have started to demonstrate the value of berries in cognitive health in older women. “Greater intakes of blueberries and strawberries were associated with slower rates of cognitive decline,” said Devore and colleagues in a research report on berries. They point to the benefits of flavonoids, especially anthocyanidins, found in berries.

An array of nutrients and bioactive components of foods, along with the gut microbiome itself, likely all play a role in cognitive health, explain Puri and colleagues. While there is much more to learn about nutrition and cognitive health, several science-based eating plans shine a light into maintaining health through evidence-based dietary choices.