Do Omega-3 Fatty Acids Really Make You Smarter? And If So, Which One?

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Eating fish for its omega-3 fatty acids has long been popularized as a brain food. Numerous studies have investigated the benefits of getting your omega-3’s from cold water fatty fish such as salmon, blue fin tuna and sardines; however, not all studies are in agreement that omega-3 fatty acids actually do help with memory. To help clarify the debate, Canadian researchers from the University of Alberta Faculty of Medicine have decided to see what omega-3 fatty acid accumulates in the brain, and how it affects brain cell response to electrical stimulation.

The two primary omega-3 fatty acids found in significant amounts in some species of fish and in algae are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA is generally associated with positive benefits that act on lowering coronary heart disease, high triglycerides (fats in the blood), high blood pressure and inflammation. DHA, however, has been more associated in numerous studies to be beneficial for the proper functioning of the adult brain, and for the development of the nervous system and visual abilities during the first 6 months of life in infants.

One of the health concerns of the EPA and DHA omega-3 fatty acids is that a typical Western diet leaves the majority of the population deficient in omega-3’s and that as a result, long-term effects toward aging are manifesting slowly but surely, that otherwise may be preventable.

In one study published earlier this year in the journal Neurology, researchers have found evidence that individuals with low levels of omega-3 fatty acids have smaller brain volumes that are equivalent to “two years’ worth of structural brain sagging.” In a study of approximately 1,500 participants who on average were 76 years old and without dementia, researchers performed MRI scans, gave mental agility tests and measured omega-3 blood levels for comparison.

What they found was that that the study participants whose DHA levels measured at the bottom 25% had smaller brain volumes and scored lower on tests of visual memory, problem solving and multi-tasking and abstract thinking compared to the participants who had higher DHA levels and larger brains.

In the Canadian study recently published in the journal Applied Physiology, Nutrition, and Metabolism, the researchers fed laboratory mice a diet high in DHA, after which the amount of DHA was analyzed in the brain. What they found was that the DHA accumulated in the hippocampus of the brain where memory function is relegated and that the concentration of DHA was 30% higher in mice fed a high-DHA diet than mice fed a normal diet.

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"We wanted to find out how fish intake improves memory," says Yves Sauve, a medical researcher at the University of Alberta who works in the department of physiology, the department of ophthalmology and the Centre for Neuroscience and is the principal investigator of the study.

The hippocampus regions of the high-DHA diet fed mice and normal diet fed mice were sliced and then subjected to high-frequency electrical stimulation. What the researchers observed was that the hippocampal brain cells of the DHA-fed mice had increased synaptic responses in comparison to the mice that were not fed DHA.

"What we discovered is that memory cells in the hippocampus could communicate better with each other and better relay messages when DHA levels in that region of the brain were higher. This could explain why memory improves on a high-DHA diet."

A second finding was that the brain will store additional reserves of the DHA omega-3 fatty acid when a diet is supplemented with extra DHA, which means that taking supplements or eating oily fish rich in omega-3’s could prevent DHA levels from decreasing during the aging process.

Recommendations for maintaining omega-3 fatty acid levels include taking fish oil supplements of 3,000-4,000 milligrams per day of fish oil, or eating 2-3 servings (which corresponds to approximately 1,000-2,500 milligrams of EPA and DHA) of fatty fish per week. An important reminder with taking fish oil supplements is to read the label and check the actual content of EPA and DHA, as some brands contain differing amounts.

For more information about how fish oil supplements compare, follow this link to an informative article about a Consumers Report study comparing fish oil pills and an article comparing krill oil to fish oil as an omega-3 fatty acid supplement to keep your brain sharper and younger, if not smarter.

Image Source: Courtesy of MorgueFile
References:

“DHA supplementation enhances high-frequency, stimulation-induced synaptic transmission in mouse hippocampus”
Applied Physiology, Nutrition, and Metabolism, 20 June 2012;

“Red blood cell omega-3 fatty acid levels and markers of accelerated brain aging”
Neurology, 2012; 78 (9): 658; Z. S. Tan et al.

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