Fish has had a reputation as a “brain food” for generations because of its high concentration of two important omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The benefit of fish comes mostly from these essential acids that the body cannot produce on its own. Although omega–6 fatty acids are abundant in Western diets, our body cannot use them to synthesize omega-3 fatty acids. We have to eat them instead.
In the nineteenth century cod liver oil was a popular source of vitamin D. Ever since the discovery in the twentieth century that the Inuit people of Greenland have a low risk of heart disease despite a hefty diet of fat, fish oil has been investigated for its beneficial effects on the heart. Taken together, fish oil and exercise both lower triglycerides and reduce the risk of heart attack and stroke.
A January 2014 study in Neurology, the medical journal of the American Academy of Neurology, showed that individuals with higher levels of omega-3 fatty acids have larger brain volumes in their old age. These correlated with preserving one to two years of brain health.
Shrinking brain volume is a sign of Alzheimer’s disease as well as normal aging. The Neurology study measured omega-3 levels in 1,111 women along with their memory aptitude. Eight years later, at an average age of 78, MRI scans measured their brain volume. Those with higher levels of omega-3s had significantly larger brain bulks. The implication is that preserved brain volume correlates with better memory in older subjects.
According to study author Dr. James Pottala, higher levels of these fatty acids suggest that their effect on brain volume is equivalent to delaying the normal age-related loss of brain cells by one to two years. Individuals with a high level of omega-3s also have a larger volume in the hippocampus, which is crucial in forming memories. In Alzheimer’s disease the hippocampus atrophies even before symptoms appear.
You can ingest fish oil by taking capsules or eating fish. Species rich in the oils include mackerel, tuna, salmon, sturgeon, mullet, bluefish, anchovy, sardines, herring, trout, and menhaden. Either way, you brain will thank you.