Fish oil supplements could help Alzheimer’s patients maintain a healthy weight, a new study in the Journal of the American Geriatrics Society shows.

People begin losing weight in the early stages of Alzheimer’s disease and get thinner as the disease progresses, Dr. Gerd Faxen Irving of Karolinksa University Hospital Huddinge in Stockholm and her colleagues note in their report. Several factors may contribute, they add, including inflammation, dulling of taste and smell, and the roaming and fidgeting characteristic of the disease, which may cause people to burn more calories.

Given that people with Alzheimer’s disease have low levels of omega-3 fatty acids that drop further as the disease progresses, Irving and her team investigated whether supplementing with these nutrients might improve weight and appetite. They randomly assigned 204 men and women with mild to moderate Alzheimer’s to 0.7 grams of docosahexaenoic acid (DHA) and 0.6 grams of eicosapentaenoic acid (EPA) or a placebo for 6 months, after which both groups took the supplements for an additional 6 months.

At the study’s outset, patients weighed 70 kilograms (154 pounds), on average. Six months later, the omega-3 group had gained 0.7 kilograms (1.5 pounds), but the placebo group’s average weight was unchanged.

After 1 year, the men and women who had been on omega-3s for the full 12 months had gained 1.4 kilograms (3 pounds). The placebo group also gained a moderate amount of weight after being switched to omega-3s. Omega-3s improved appetite as rated by caregivers in both groups.

The difference in weight gain between the two groups did not reach statistical significance, but the fact that further analysis found that weight gain rose in tandem with blood levels of DHA supports the benefit of the supplements for maintaining weight, Irving and her colleagues say.

They conclude: “A DHA-enriched omega-3 fatty acid supplement may positively affect weight and appetite in patients with mild to moderate Alzheimer’s disease.”

SOURCE: Journal of the American Geriatrics Society, January 2009.