People with higher levels of omega 3 fatty acids have larger brain volumes; these acids can be found in fish oil.

Researchers tested the omega-3 fatty acids EPA+DHA levels in the bloodstreams of 1,111 women, an American Academy of Neurology news release reported.

The study subjects were members of the Women's Health Initiative Memory Study. Eight years after the blood test the women were given an MRI to measure their brain volume; at this time the women had an average age of 78.

The study participants with higher levels of omega-3s were found to have larger brain volumes eight years later.  People with twice the levels of omega-3s (7.5 vs. 3.4 percent) had about a 0.7 percent 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," study author James V. Pottala, PhD, of the University of South Dakota in Sioux Falls and Health Diagnostic Laboratory, Inc., said in the news release.

Those with higher levels of omega-3 fatty acids also had a 2.7 percent larger volume in the hippocampus region, a part of the brain that plays a key role in memory. The first signs of Alzheimer's is atrophy to the hippocampus region of the brain.

Omega-3 fatty acids are known for "controlling blood clotting and building cell membranes in the brain," the Harvard School of Public Health reported. It can also improve conditions such as "cancer, inflammatory bowel disease, and other autoimmune diseases such as lupus and rheumatoid arthritis."

The findings were published in the January 22, 2014, online issue of Neurology®, the medical journal of the American Academy of Neurology. The research was supported by the  by the National Heart, Lung, and Blood Institute.