Eating foods rich in DHA omega-3 fatty acids are supposed to be good for your brain and memory. Many studies have associated eating omega-3 foods and improved cognitive function, yet no cause and effect relationship has been found. But now Canadian researchers say they may have discovered why DHA omega-3 is good for your brain.
Omega 3 benefits
Fish is considered “brain food” because some species—salmon, tuna and sardines in particular, have a lot of omega-3 fatty acids in the form of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA has been associated with a lower risk of heart disease, high triglycerides, high blood pressure and inflammation. Numerous studies have associated DHA with improved brain function and memory.
Researchers have been able to observe sharper memory in people on a diet rich in DHA, yet an explanation of exactly how docosahexaenoic acid improves memory has been elusive. But in a report published in the journal Applied Physiology, Nutrition and Metabolism, researchers at the University of Alberta say they may have pinpointed the actual physiological changes caused by DHA that improve memory.
How DHA improves memory
After feeding one group of mice a high-DHA diet and another group a normal diet, the researchers found that the DHA accumulated in the hippocampus, the area of the brain that controls memory. The mice on a diet high in DHA had concentrations 30 percent higher than the mice eating normally. But this finding alone didn’t explain how DHA improves memory.
Next, the researchers took cross sections of hippocampus from mice in both groups and stimulated them with a high-frequency electrical current. The hippocampus samples from mice brains with higher concentrations of DHA had higher synaptic responses than those from the other mice. Essentially, the memory cells could relay messages more efficiently immersed in higher concentrations of DHA.
Why DHA slows cognitive decline
Other studies have found that while increasing DHA can slow the rate of cognitive decline, it won’t improve memory for people who have already slipped into dementia. The Canadian study may have an explanation for that as well. The researchers found that the brains of mice on a diet supplemented with extra DHA accumulated a reserve stockpile of the compound.
If human brains actually store a reserve of DHA like the mice brains, it could mean that taking DHA supplements or eating more fish rich in omega-3’s keep your mind and memory sharp by preventing DHA levels in your hippocampus from decreasing as you age.
The foods richest in omega-3 fatty acids:
- Flax seeds