Alzheimer's disease: slowed course with omega-3 fatty acids

OmegaAD study reveals that supplementation with omega-3 from fish oil slows cognitive decline in Alzheimer's disease in moderate forms. Alzheimer's disease is a severely debilitating disease characterized by progressive decline in cognitive abilities, learning, and memory. Medications treat the symptoms, but have no effect on the causes of the disease and its progression.

Epidemiological studies suggest that a diet rich in fish may protect against the onset of Alzheimer's disease, so researchers decided to investigate the role of the omega-3 fatty acids EPA and DHA. The Swedish OmegaAD study, led by scientists at "Karolinska Institutet," is the first clinical trial to use fish oil in the treatment of Alzheimer's disease. The results obtained indicate that supplementation with omega-3 fatty acids from fish oil can slow cognitive decline in some patients with a very moderate form of Alzheimer's disease, although this does not appear to be the case in patients suffering from a more advanced form of the disease.

Omega-3s slow cognitive decline associated with Alzheimer's disease

The study involved 204 patients with mild to moderate Alzheimer's disease in a disease-stabilized condition. These patients were randomly assigned to take omega-3 fatty acids (1.7g DHA and 0.6g EPA) or placebo, for 6 months. After 6 months, all subjects received omega-3 fatty acid supplementation for another 6 months. At the end of the first 6 months in a subgroup of patients (n=32) with very mild cognitive dysfunction, a significant reduction in cognitive decline was observed among patients treated with omega-3 fatty acids compared with patients taking placebo. Similarly, a slowdown in cognitive decline was observed between the 6th and 12th month in the subgroup taking placebo when supplementation with EPA and DHA omega-3 fatty acids began.

Not effective for the more advanced form of Alzheimer's disease

In contrast, no difference in the progress of cognitive decline was observed in patients with a more advanced form of the disease. The researchers argue that the mechanisms by which omega-3 fatty acids operate are not entirely clear, but that their powerful anti-inflammatory abilities could justifiably play a key role in preventing the onset of Alzheimer's disease. It appears that in the two years prior to disease onset there is a strong inflammatory state, potentially treatable. It is essentially possible that the clinical stage at which Alzheimer's disease becomes clinically evident is characterized by such neural impairment that even potent anti-inflammatory treatment such as omega-3 fatty acids may be futile.

Source 

Omega-3 fatty acid treatment of 174 patients with mild to moderate Alzheimer's disease (OmegAD): a randomized double-blind trial, Freund Levi et al, Archives of Neurology, 2006;63:1402-1408.