Older women with higher levels of Omega-3 fatty acids in their blood had larger brain volumes than women with lower levels of the fatty acid, according to a study Reuters reported.

Researchers found that omega-3s, found in fish and fish oil, protect the brain from the loss of brain cells that occurs with normal aging and is seen more severely in people with dementia.

"The brain gets smaller during the normal aging process - about 0.5 percent per year after age 70, but dementia is associated with an accelerated and localized process of brain shrinkage," James Pottala, who led the study, told Reuters.

The eight-year study, which was published Jan. 22 on the journal Neurology, involved more than 1,000 older women who were, on average, 70 years old and had no signs of dementia at the beginning of the study, HealthDay reported.

Throughout the study, researchers measured the amounts of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the participants' red blood cells. The women also had MRI scans that measured their brain volumes. At the time of the scans, the women were an average of 78 years old.

Researchers found that participants whose omega-3 levels were twice as high had a 0.7 percent higher brain volume.

"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," Pottala said in a press release.

Higher levels of the fatty acid were also associated with greater volume in the hippocampus, the region of the brain in which the memory-robbing disease Alzheimer's first attacks, HealthDay reported.

Gregory Cole, associate director of the Mary S. Easton Center for Alzheimer's Disease Research at the University of Southern California, told HealthDay the study offers valuable information.

"[The study] has a large number of subjects with an objective measure -- the measure of brain volume," Cole said. "Studies that measure things like [memory and thinking] are not as concrete. People have good days and bad days, but when you measure brain volume you get a pretty repeatable measure."

Pottala said that higher levels of Omega-3 fatty acids can be achieved through diet and the use of supplements.