Women with high blood levels of fish oils have larger brain volumes then those with lower levels, suggesting the oils may delay the normal loss of brain cells due to aging, research found.
Those who raised their levels of two major omega-3 fatty acids by eating fish or taking supplements had larger total brain volume than those who didn’t, according to research posted online today by the journal Neurology.
As people age, their brains get smaller but the shrinkage is accelerated in those with dementia or Alzheimer’s disease, the authors said. While today’s findings suggest that larger brain volumes equal a one- to two-year delay in the normal loss of brain cells, more studies are needed to look at what that means for memory, said James Pottala, the lead study author.
“Omega-3s are building blocks for brain cell membranes” said Pottala, assistant professor of internal medicine at the University of South Dakota in Sioux Falls and principal biostatistician at Health Diagnostic Laboratory Inc. in Richmond, Virginia, in a Jan. 20 e-mail. If achieving certain omega-3 levels “can prevent or delay dementia, that would have huge mental health benefits, especially since levels can be safely and inexpensively raised through diet and supplementation.”
More than 5 million people in the U.S. have Alzheimer’s disease, a number projected to triple by 2050, according to the Alzheimer’s Association. There is no treatment for the mind-debilitating disease. The only drugs approved for the condition ease symptoms for a few months while the disease continues to worsen.
Researchers looked at 1,111 post-menopausal women from the Women’s Health Initiative Memory Study. During that trial, women had their red blood cell levels tested for eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA, two major fish-derived omega-3 fatty acids, Pottala said. Eight years later, MRI scans were taken to measure their brain volume when they were an average age of 78 years.
They found that those whose omega-3 fatty acid levels were twice as high, 7.5 percent, had 0.7 percent larger brain volume. Those with the higher levels also had a 2.7 percent larger volume in the hippocampus area of the brain, which plays an important part in memory and can begin to atrophy in Alzheimer’s disease before symptoms even appear.
While the study didn’t measure how much fish or supplements the women consumed, previous research showed that healthy men and women eating non-fried oily fish like tuna, salmon or herring twice a week and taking fish oil supplements had a mean red blood cell level of EPA and DHA of 7.5 percent, Pottala said.
The brain uses DHA to make anti-inflammatory compounds that may help prevent cell death. Also the brain cell membranes are made up of DHA and insufficient amounts may cause the brain matter to decline over time, he said.
More studies are needed looking at men and women at risk for dementia and whether increasing their fish oil dose until their red blood cell levels were more than 8 percent benefited them, Pottala said.