November 2, 2022
More good news on the food and brain health front: A new study found that people in their 40s and 50s with high levels of omega-3s, the fatty acids found in salmon, cod and other fish, tended to have a larger hippocampus, a brain region critical for memory. The hippocampus is among the first areas affected by Alzheimer’s disease. Those who had high levels of omega-3 also had better cognitive function than their peers with low levels of the healthy fats.
Earlier research had pointed to the benefits of fish for protecting the brains of older adults. The new findings suggest that the brain benefits of seafood begin early and can help to keep the brain young, potentially warding off or delaying the onset of Alzheimer’s disease in old age.
“The new contribution here is that, even at younger ages, if you have a diet that includes some omega-3 fatty acids, you are already protecting your brain for most of the indicators of brain aging that we see at middle age,” said the study’s lead author, Claudia Satizabal, of the University of Texas Health Science Center at San Antonio.
For the study, researchers looked at 2,183 men and women whose average age was 46. All were free of Alzheimer’s disease or other forms of dementia. They also underwent genetic tests to determine whether they carried the APOE-e4 gene, which increases the risk of eventually developing Alzheimer’s disease.
The researchers also measured red blood cell levels of the fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the “good” fats found in fish. Levels of these healthful fatty acids rise when you eat more foods rich in omega-3s, including cold-water fish like salmon, cod, tuna, mackerel, herring, anchovies, trout and sardines. Participants also underwent MRI brain scans and other tests to assess the overall health of their brains.
The study found that the higher the blood levels of omega-3s, the larger the volume of the hippocampus, an area of the brain that is critical for learning and memory. The hippocampus is one of the first brain areas affected by Alzheimer’s disease. Those with higher omega-3 levels also tended to score higher on tests of reasoning and logic.
And it didn’t take eating much fish to see brain benefits. “Although the more omega-3 the more benefits for the brain, you just need to eat some to see benefits,” Dr. Satizabal said. “We don’t understand everything yet, but we show that, somehow, if you increase your consumption of omega-3s even by a little bit, you are protecting your brain.”
The researchers also found that among people who carried the APOE-e4 gene, higher omega-3 levels were associated with greater health of small blood vessels. Impaired small blood vessels in the brain are tied to an earlier onset of symptoms of Alzheimer’s disease and other forms of dementia. Omega-3s also fight inflammation, which may damage organs throughout the body, including the brain.
“Omega-3 fatty acids such as EPA and DHA are key micronutrients that enhance and protect the brain” and may help to counter the increased genetic risks posed by APOE-e4, said study author Debora Melo van Lent. “If there is a modifiable risk factor that can outweigh genetic predisposition, that’s a big gain.”
Greater dietary consumption of fish and other seafood, a staple of the heart-healthy Mediterranean diet, might also reduce the intake of other less healthy fats. For example, a serving of fish might substitute for less healthy choices like a cheeseburger or a slice of pepperoni pizza that are high in artery-clogging saturated fats.
Regardless of your age, it’s never too early or too late to eat foods that may promote better brain health. The easiest way to increase omega-3 intake is to eat more fatty fish, such as salmon, tuna, anchovies or trout. For vegetarians, good plant sources of omega-3 fats are ground flaxseeds, chia seeds and walnuts.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Claudia L. Satizabal, PhD; Jayandra J. Himali, PhD; Alexa S. Beiser, PhD; et al: “Association of Red Blood Cell Omega-3 Fatty Acids with MRI Markers and Cognitive Function in Midlife – The Framingham Heart Study.” Neurology, October 5, 2022