Omega-3 again linked to Alzheimers protection
and agitation symptoms associated with Alzheimer's disease, says a
new clinical trial.
The randomised, double-blind, placebo-controlled clinical trial, published in the International Journal of Geriatric Psychiatry, with 174 patients with Alzheimer's is yet another positive result for the fatty acids in relation to cognitive function. Last year the same researchers reported omega- may slow mental decline in people with very mild Alzheimer's disease (Archives of Neurology, Vol. 63, pp. 1402-1408). Alzheimer's disease is the most common form of dementia and currently affects over 13 million people worldwide. The direct and indirect cost of Alzheimer care is over $100 bn (€ 81 bn) in the US alone. The direct cost of Alzheimer care in the UK was estimated at £15 bn (€ 22 bn). The new study, led by Yvonne Freund-Levi from Sweden's Karolinska Institutet, divided the participants to receive omega-3 supplements (docosahexaenoic acid (DHA) 1.7 g and eicosapentaenoic acid (EPA) 0.6 g) or placebo for six months. After this initial six month period, all participants received the omega-3 supplements for six further months. The genotype of the participants was also measured to identify their apolipoprotein genes. Cognitive performance declines naturally with age, but genetics does play a part in the complex progression of Alzheimers. Indeed, in 1993 scientists reported that people with a gene that codes for the blood lipoprotein, apolipoprotein E4 (apoE4) have a higher risk of developing Alzheimer's disease at an earlier age than people with apoE2 or apoE3. While no observable difference was observed between the patients receiving the omega-3 and the placebo group, when the researchers took into account ApoE4 genotype, an appreciable difference appeared. Carriers of the gene who had received omega-3 supplements responded positively to the omega-3 as regards agitation symptoms, while non-bearers of the gene showed an improvement in depressive symptoms. The researchers called for larger studies on individuals with more pronounced neuropsychiatric symptoms to confirm these results before any general recommendations can be made. "Supplementation with omega-3 in patients with mild to moderate AD did not result in marked effects on neuropsychiatric symptoms except for possible positive effects on depressive symptoms in non-APOE4 carriers and agitation symptoms in APOE4 carriers," concluded the researchers. Although the mechanism of Alzheimer's is not clear, more support is gathering for the build-up of plaque from beta-amyloid deposits. The deposits are associated with an increase in brain cell damage and death from oxidative stress. But how omega-3 fatty acids may interfere with the development of Alzheimer's disease is not clear, said the authors, but suggested that the benefits may be linked to the fish oil's anti-inflammatory effects, although no such effects were observed in this study. Source: International Journal of Geriatric Psychiatry Published online 21 June 2007, doi 10.1002/gps.1857 "Omega-3 supplementation in mild to moderate Alzheimer's disease: effects on neuropsychiatric symptoms" Authors: Y. Freund-Levi, H. Basun, T. Cederholm, G. Faxen-Irving, A. Garlind, M. Grut, I. Vedin, J. Palmblad, L.-O. Wahlund and M. Eriksdotter-Jönhagen
