MINNEAPOLISIndividuals who consume a diet high in omega-3 fatty acids found mainly in oily cold-water fish, such as salmon, herring, sardines, swordfish and mackerel, may have larger brain volumes in old age equivalent to preserving one to two years of brain health, according to a new study published online in the journal Neurology. The findings suggest higher levels of omega-3s could prevent or delay Alzheimers as well as normal aging.
For the study, the levels of omega-3 fatty acids EPA and DHA in red blood cells were tested in 1,111 women with an average age of 80 who were part of the Women's Health Initiative Memory Study. After an 8-year follow-up, MRI scans were taken to measure their brain volume. Those with higher levels of omega-3s had larger total brain volumes eight years later. Those with twice as high levels of fatty acids (7.5% versus 3.4%) had a 0.7% larger brain volume.
"These higher levels of fatty acids can be achieved through diet and the use of supplements, and the results suggest that the effect on brain volume is the equivalent of delaying the normal loss of brain cells that comes with aging by one to two years," said study author James V. Pottala, Ph.D., of the University of South Dakota in Sioux Falls and Health Diagnostic Laboratory, Inc., in Richmond, Va.
Those with higher levels of omega-3s also had a 2.7% larger volume in the hippocampus area of the brain, which plays an important role in memory. In Alzheimer's disease, the hippocampus begins to atrophy even before symptoms appear.
Interestingly, a 2013 study published in the journal Neurology suggests omega-3 fatty acids may have no effect on age-related loss of brain function. While the findings refute past research linking omega-3s to improved cognitive health, researchers at the University of Iowa who conducted the current study do not recommend people change their diet based on these results.