Forgetting to include omega-3 in your diet could lead to forgetting other things, according to a new research that suggests a diet lacking in omega-3 fatty acids could negatively impact visual memory and other brain functions.
The study, published on Tuesday in the journal Neurology, discovered a link between docosahexaenoic acid (DHA) — one of the nutrients in omega-3 fatty acids — and brain volume; memory; and executive functions, such as problem solving, planning and abstract thinking. Researchers gave brain scans to 1,575 subjects with an average age of 67 years and no history of dementia, and tested them for mental function, body mass and the omega-3 fatty acid levels in their red blood cells.
The results indicated that the participants with DHA levels in the lowest 25% of the subjects had lower brain volume compared with those in the highest 25%. Participants with levels of all omega-3 fatty acids — DHA, eicosapentaenoic acid (EPA) and others — scored lower on visual memory and executive function tests.
“People with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain aging,” said study author Zaldy Tan, of the Easton Center for Alzheimer’s Disease Research and the Division of Geriatrics at the University of California at Los Angeles.
It’s important to note that few of the participants were taking omega-3 supplements, according to Dr. Tan, who was quoted in the New York Times. “The main reason that some had higher blood levels of omega-3s was that they ate more fatty fish,” Tan said.
What are omega-3 fatty acids?
Omega-3 fatty acids, also known as polyunsaturated fatty acids, are essential fatty acids, which means they can’t be created by the human body but are vital to our health. Research has linked omega-3s to a variety of health benefits, including lower risk of heart disease, cancer, arrhythmias (abnormal heartbeats) and arthritis; decreased triglyceride levels and blood pressure; slow growth rate of atherosclerotic plaque; and a reduction in depression symptoms. According to the American Heart Association, “Omega-3 fatty acids benefit the heart of healthy people and those at high risk of — or who have — cardiovascular disease.”
What foods contain large amounts of omega-3s and DHA?
The best way to increase your intake of DHA is through fish or shellfish. Salmon, tuna, sardines, shrimp, scallops and herring are all high in DHA.
While many food products tout omega-3 labels, be aware that it doesn’t mean they’re a significant source of the fatty acids. For example, “a carton of Breyers Smart HA Omega-3 yogurt has less DHA than a teaspoon of salmon,” according to USA Today.
Not a seafood fan? You can still get your omega-3s from flax seeds, walnuts, soybeans, fortified yogurt, fortified eggs, fortified milk (or soymilk) and fortified orange juice.
How much omega-3 is recommended per day?
The American Heart Association recommends eating at least two servings of fish, like the ones we listed above, a week. One serving is equivalent to 3.5 ounces of cooked fish, or about ¾ cup of flaked fish. The AHA also recommends mixing it up and eating various types of fish in order to avoid any potential risk from environmental pollutants.
If you have heart disease, the AHA suggests consuming about 1 gram of EPA and DHA a day. If you have high triglycerides, take 2 to 4 grams under a doctor’s supervision.
Pregnant and breast-feeding women should try to consume 200 to 300 milligrams of DHA a day, though they also shouldn’t be eating large amounts of fish because of the mercury content. Instead, try fish oil pills or supplements. The National Institute of Health also advises parents to limit children’s consumption of fresh fish because of the mercury.