Could Higher Omega-3s Preserve Brain Health in Old Age?

Higher levels of the omega-3 fatty acids found in fish oil could help to preserve brain volume—and brain health—in old age, according to a new study published online in Neurology. Shrinking brain volume, which happens as part of the normal aging process, can also be a sign of Alzheimer’s disease. Investigators found that postmenopausal women with higher levels of omega-3s had larger total brain volumes years later, which had an effect equivalent to preserving 1 to 2 years of brain health. They tested the levels of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the red blood cells of 1,111 women who participated in the Women’s Health Initiative Memory Study. The researchers measured the women’s brain volume by performing MRI scans 8 years later when the average age of participants was 78. Those with greater red blood cell EPA + DHA (omega-3 index) levels had larger total brain volumes at that time. While senior study author William Harris, PhD, says they have not identified why higher omega-3 fatty acid levels appear to preserve brain health, they have determined two important findings. “One, the brain contains a relatively large amount of DHA, one of the two ‘fish’ omega-3s, and two, DHA can be converted into a wide variety of anti-inflammatory compounds that could help preserve cell viability and ultimately slow the loss of brain cells,” says Harris, a senior scientist at Health Diagnostic Laboratory, Inc., in Richmond, Va. Study participants with a 7.5% omega-3 index level had a 0.7% larger brain volume than those with omega-3 index levels of 3.4%. Those with higher levels of omega-3s also had a 2.7% larger volume in the hippocampus, an area of the brain which plays an important role in memory and usually begins to atrophy in those with Alzheimer’s disease even before symptoms appear. “We recommend that patients try to achieve an omega-3 index of 8% or greater, but there is likely benefit from increasing the typical American level of about 4% to 6%,” Harris says. “There are no downsides, only up.” He suggests that an intake of 500mg to 1000mg of EPA + DHA is a good target. “That would require eating 3 to 4 servings of oily fish per week or taking 2 to 3 standard fish oil capsules,” Harris says. “I always recommend ‘oily fish’ (salmon, mackerel, herring, albacore tuna, sardines, oysters) first, if possible, and supplements only if people can’t or won’t eat fish.” However, he says both options are essentially equivalent in terms of raising the omega-3 index. The authors suggested that future studies should examine whether maintaining higher red blood cell EPA + DHA levels slows the rate of hippocampal or overall brain atrophy. —Colleen Mullarkey Reference Pottala JV, Yaff K, Robinson JG, Espeland MA, Wallace R, Harris WS. Higher RBC EPA + DHA corresponds with larger total brain and hippocampal volumes. Neurology. January 22, 2014. [Epub ahead of print.]