Omega-3 supplements can, in certain cases, help combat the depression and agitation symptoms associated with Alzheimer’s disease, according to a clinical study conducted at the Swedish medical university Karolinska Institutet.

A number of epidemiological studies have shown that eating fatty fish provides a certain degree of protection against Alzheimer’s and other dementia diseases—an effect often thought attributable to the omega-3 fatty acids it contains. Some studies also suggest that omega-3 can have a therapeutic effect on some psychiatric conditions.

Researchers at Karolinska Institutet and Uppsala University have now examined whether omega-3 supplementation has any effect on the psychiatric symptoms associated with Alzheimer’s disease. Just under 200 patients with mild Alzheimer’s were divided into two groups, one of which received omega-3, and one a placebo. The study lasted for one year.

There was no observable difference in therapeutic effect between the patients receiving the omega-3 and the placebo group. However, when the researchers took into account which of the patients carried the susceptibility gene APOE ?4 and which did not, an appreciable difference appeared. Carriers of the gene who had received active treatment responded positively to the omega-3 as regards agitation symptoms, while non-bearers of the gene showed an improvement in depressive symptoms.

The team points out that no general therapeutic recommendations can be made from the results until larger studies on individuals with more pronounced neuropsychiatric symptoms are conducted.

Omega-3 supplementation in mild to moderate Alzheimer’s disease: effects on neuropsychiatric symptoms
Yvonne Freund-Levi, Hans Basun, Tommy Cederholm, Gerd Faxén-Irving, Anita Garlind, Mikaela Grut, Inger Vedin, Jan Palmblad, Lars-Olof Wahlund and Maria
Eriksdotter-Jönhagen
International Journal of Geriatric Psychiatry, doi 10.1002/gps.1857