A new study provides further evidence that a diet rich in fish can support long-term brain health. Nine years after healthy volunteers (all over 65) reported their eating habits, scientists (1)conducted MRIs on the same group of subjects. The result: people who ate fish at least once per week at the start of the study had less atrophy nine years later in the areas of the brain prone to Alzheimer’s disease and important for memory and cognition.
This finding isn’t entirely new. Previous studies have also reported that higher blood levels of EPA and DHA, both omega-3 fatty acids found in many fish, are associated with less brain atrophy (2) and other symptoms of brain aging(3).
Do fish oil supplements provide the same benefit? This latest study would suggest not, but the evidence remains inconclusive. Supplements can provide high levels of DHA and EPA, but do not supply lean protein, selenium, iron, iodine, zinc and vitamins that may contribute to brain health. In this study, the level of DHA or EPA in fish was apparently not important to the perceived protection from brain atrophy. Other studies have also reported that though brain health in older people is associated with high fish intake and high DHA or EPA blood levels, it is not necessarily associated with DHA/EPA intake specifically.
If these results confuse you, you’re not alone. There are many unanswered questions. Supplement use was not recorded in this study and it’s possible that many study participants used fish oil supplements. Today, more than 37 percent of adults take fish oil supplements, making them the most popular supplements on the market(5). If participants were using fish oil supplements, then the additional impact of DHA or EPA from fish might have been difficult to separate. On the other hand, mounting evidence consistently suggests that supplements rarely provide the same benefits as a balanced, whole-food diet(6).
More research is clearly needed. For now, this study provides a bit more evidence that a healthy diet includes regular fish intake. For more information on whether fish and DHA omega-3 fatty acids can protect the aging brain, read our report on fish and long-chain omega-3 fatty acids, DHA & EPA.
1. Raji, C.A., et al., Regular Fish Consumption and Age-Related Brain Gray Matter Loss. Am J Prev Med, 2014.http://www.ncbi.nlm.nih.gov/pubmed/25084680
2. Samieri, C., et al., Plasma long-chain omega-3 fatty acids and atrophy of the medial temporal lobe. Neurology., 2012
3. Tan, Z.S., et al., Red blood cell omega-3 fatty acid levels and markers of accelerated brain aging. Neurology., 2012. 78(9): p. 658-664
4. Barnes, P.M., B. Bloom, and R.L. Nahin, Complementary and alternative medicine use among adults and children: United States, 2007. Natl Health Stat Report, 2008(12): p. 1-23.http://www.ncbi.nlm.nih.gov/pubmed/19361005
5. Mitka, M., Emerging data continue to find lack of benefit for vitamin-mineral supplement use. JAMA, 2014. 311(5): p. 454-5.http://www.ncbi.nlm.nih.gov/pubmed/24496522
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