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Eating More Omega-3s Can Improve Cognitive Function, Study Says

More evidence that what’s good for the heart is good for the head.

Have you caught your quota of fish and omega-3s this week? Eating at least two servings of fish each week has been recommended for supporting cognitive function in addition to your cardiovascular health for many years. Oily fish like salmon, mackerel, sardines, and tuna, are the best source of the key nutrient, omega-3 fatty acids.

With more than 6.5 million people in the United States over age 65 living with Alzheimer's disease, most adults probably know someone suffering from dementia—and what they've witnessed frightens many. You may be more conscious of your omega-3 consumption after learning the results of a new study that specifically looked at the impact of diet on the brains of people in the middle of life.

While you, too, may find the loss of memory and the inability to think clearly or make decisions terrifying, scientific research increasingly argues that dementia isn't inevitable with advanced age, and we can reduce our risk of developing the mind-robbing disease through diet.

New findings

eating salmon

Recently researchers from The Biggs Institute for Alzheimer's & Neurodegenerative Diseases at UT Health San Antonio and others brain research institutions investigated the association between omega-3 fatty acid concentrations in red blood cells and cognitive markers of brain aging in middle-aged adults. Their study, published in 2022 in Neurology, included 2,183 brain-healthy participants from the Third-Generation and Omni 2 cohorts of the Framingham Heart Study.

The scientists measured subjects' blood concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the long-chain omega-3 polyunsaturated fatty acids found in most abundance in oily fish. Then they used brain MRIs to measure participants' brain volumes, including total gray matter, hippocampal and white matter volumes. Comparing omega-3 concentrations to those brain measure as well as such cognitive functions as memory and reasoning, researches found a correlation between higher omega-3s and larger brain volume and better cognitive ability.

In addition, fish oil appeared to be protective to carriers of a gene variant called APOE e4, which puts them at greater risked for Alzheimer's, according to the study. APOE-e4 carriers with higher DHA concentrations showed larger hippocampal volumes, while higher EPA in the blood was related to better abstract reasoning.

"This is a compelling study that highlights an important association between omega-3s and cognitive function, and continues to build the foundation of using food as medicine," says Uma Naidoo, MD, a Harvard-trained nutritional psychiatrist, professional chef, and author of the bestselling book This Is Your Brain on Food. "Without a doubt, omega-3 fatty acids are one of the critical nutrients I recommend for supporting mental health through nutrition."

Oil change

Your body doesn't produce omega-3s  so the best way to ensure you get this important nutrient is by eating more fish. You can get a plant-based omega-3 called alpha-linolenic acid (ALA) by eating walnuts, flaxseeds, chia sees, and canola oil, but your body must convert ALA to DHA and EPA. Omega-3-enriched eggs and peanut butter are other sources.

But you'll get more of the good stuff by eating oily fish like herring, wild salmon, tuna (including canned tuna), mackerel, sardines, anchovies, trout, bluefish, and striped bass. For another fish story, check out our article Every Popular Fish—Ranked for Nutritional Benefits.

If you find it difficult to eat more than two servings of fish per week, you can consider taking fish oil supplements. But nutritionists and many doctors recommend getting your omega-3s directly from food.

No matter how you do it, getting more omega-3s seems like a smart idea.

Jeff Csatari
Jeff Csatari, a contributing writer for Eat This, Not That!, is responsible for editing Galvanized Media books and magazines and for advising journalism students through the Zinczenko New Media Center at Moravian University in Bethlehem, PA. Read more about Jeff