According to a study published in the January 22, 2014 on-line edition of the journal Neurology, the higher the level of fish oils in your blood, the larger your brain volume is likely to be, implying that such oils may slow down the loss of brain cells as you age.
The study team assessed the level of the marine omega-3 fatty acids DHA and EPA in the red blood cells of over 1,000 post-menopausal women. Eight years later, the women’s brain volumes were measured using MRI scans. The average age of the participants was 78 at the time of the brain scans.
Study subjects with omega-3 levels twice (7.5 percent) as high as those in the lowest range demonstrated a 0.7 percent higher brain volume. In addition, higher levels of omega-3 were associated with greater (2.7 percent) hippocampal volume. The hippocampus is the area of the brain first ravaged by the effects of Alzheimer’s disease.
The study authors state that the results translate to a one- to two-year delay in the expected amount of brain cell loss associated with aging. Author Pottala affirmed that “omega-3s are building blocks for brain cell membranes”. If increasing one’s levels of such oils can avert or postpone dementia, this would result in major mental health benefits – and all through the modification of one’s food intake and supplement regime. Currently there are no medications available that do more than alleviate the symptoms of Alzheimer’s disease beyond several months.
According to Dr. JoAnn Manson, chief of the division of preventive medicine at Brigham and Women’s Hospital in Boston, “the results should be interpreted cautiously because it’s an observational study and not a randomized clinical trial looking at the relationship between omega-3 intake and changes in brain volume”. In other words, the study doesn’t definitively point to a cause-and-effect link. Maybe people who consume higher levels of fish oil have some other inherent advantage or lifestyle choice that increases their brain volume, for instance.
Nor did the study did clarify the optimal daily intake of omega-3 fatty acids, but according to Pottola previous research has demonstrated that healthy men and women who eat non-fried oily fish such as salmon, tuna, or herring twice a week and who take fish oil supplements have a mean red blood cell level of EPA and DHA of 7.5 percent. The American Heart Association also recommends eating at least two 3.5-ounce servings of fish a week.
Omega-3s consist of three kinds of fat: EPA and DHA, found in marine oils, and ALA, found in plant oils. It’s possible that vegetarians may be able to preserve their brain cells by consuming flax oil or ground flaxseed, which are rich in ALA, but since the current study did not look at ALA, future research is needed to determine the effect of blood levels of ALA on brain health.
Reference: Pottala, J.V., Yaffe, K., Robinson, J.G., Espeland, M.A., Wallace, R., & Harris, W.S. (2014). Higher RBC EPA + DHA corresponds with larger brain and hippocampal volumes: WHIMS-MRI Study. Neurology, 2014 Jan 22 [Epub ahead of print]