Omega-3 May Protect Against Alzheimer Disease

Omega-3 fatty acids in dietary supplements can cross the blood-brain barrier in persons who have Alzheimer disease, affecting known markers for the disease and for inflammation, according to a recent study.

The findings strengthen the existing evidence that omega-3 may benefit certain forms of the disease.

As part of the larger OmegAD project, scientists at the Karolinska Institutet in Sweden examined whether omega-3 dietary supplements change the fatty acid profile of the CNS in patients with mild Alzheimer disease. Of 33 patients in the study, 18 received a daily omega-3 supplement and 15 received a placebo for 6 months.

The first group had significantly higher levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid, both omega-3 fatty acids, in their cerebrospinal fluid and blood. No such change was seen in the placebo group.

In addition, levels of DHA correlated directly with the degree of change in Alzheimer disease and inflammatory markers in the cerebrospinal fluid.

Omega-3 and other essential polyunsaturated fatty acids accumulate in the CNS during gestation, it was noted. The acids have been assumed to be continually replaced throughout life, but little is known about how and whether changes in diet can affect the transport of important fatty acids across the blood-brain barrier.

Several diseases can affect the fatty acid profile of the CNS, the researchers stated. For example, previous research has observed lower than normal brain concentrations of DHA in patients with Alzheimer disease.

Researchers have long been interested in this link between Alzheimer disease and inflammation, but attempts to manage the disease using traditional anti-inflammatory drugs have not produced improvements in memory function, it was noted.

Much work remains to be done before it is known how these fatty acids can be used in treating patients with Alzheimer disease to halt memory loss, a coauthor suggested.

The findings appear in the Journal of Internal Medicine.