Fatty Acids May Ward Off Alzheimer's Disease

Sept. 27, 2005 (San Diego) -- A fatty acid found in corn, sunflower, and safflower oils may help prevent Alzheimer's disease in some people, researchers report.

The researchers studied two groups of people: Those with a known inherited risk factor for Alzheimer's disease, the ApoE e4 gene, and those who did not have the gene.

In people who did not have the gene, eating a diet rich in linoleic acids reduced the risk of developing Alzheimer's disease by about 50%. But in those who carried the disease-causing gene, linoleic acids appeared to raise the risk of developing the mind-robbing disease even further, says researcher Sara M. Debanne, PhD, professor of epidemiology and biostatistics at Case Western Reserve University School of Medicine in Cleveland. This was updated information presented at the American Neurological Association's 130th Annual Meeting this week.

Debanne says she suspects the fatty acids' cholesterol-lowering properties account for their protective effect in some people. Several studies have shown that the cholesterol-lowering statin drugs appear to ward off the disease.

Aaron McMurtray, MD, a neurobehavior fellow in the department of neurology at the University of California, Los Angeles, says the research "gives people good reason to be tested for their ApoE e4 gene status."

For people who do not test positive, "eating a diet rich in fatty acids is an easy, practical thing you can do on your own to change your risk," he tells WebMD.

High-Fat Diets Lower Alzheimer's Risk

The study, presented at the annual meeting of the American Neurological Association, included 117 people with Alzheimer's disease and 356 people without dementia; all were 65 years or older.

The participants or their family members were asked to fill out detailed questionnaires that asked about their eating habits when they were in their 40s and 50s.

Those who ate high-fat diets -- in which fats accounted for at least 39% of their daily calories -- were at slightly lower risk of having Alzheimer's disease, the study showed. Also, those who ate diets rich in linoleic acids -- in which linoleic acids accounted for at least 6.6% of their daily calories -- were about 45% less likely to have the mind-robbing disorder.

"But when we looked at participants by their ApoE e4 gene status, things really got interesting," Debanne tells WebMD. "High linoleic acid intake during the 40-59 year age period appeared to increase [Alzheimer's] risk for those with ApoE e4 and to decrease risk for those without the gene," she says.

The researchers hope to do future studies to figure out why the "good fatty acid" appears to be unhealthy for those with the gene.