Purpose of study: To evaluate potential treatment with use of n-3 fatty acids for those with mild to moderate Alzheimer’s disease (AD).
Research methodology: Randomized, double-blind, placebo-controlled clinical trial
Description: Researchers treated 204 patients with mild to moderate AD (ages 74 +- 9) with n-3 fatty acids or placebo for 6 months. All patients then received n-3 fatty acid treatment for the following 6 months. No cross-over trial was performed.
Patients were chosen for stability while on normal acetylcholine esterase inhibitor treatment and who had score of 15 points or more on a Mini-Mental State Examination (MMSE). During the study, the patients continued their regular treatment. Exclusions of the study included patients undergoing treatment with NSAIDs, other n-3 preparations or anticoagulants as also were those who had history of alcohol abuse or serious disease, or if did not have a caregiver.
The n-3 fatty acid treatment included 1.7g of docosahexaenoic acid (DHA) and 0.6 eicosapentaenoic acid (EPA) daily and the placebo group was treated with an isocaloric placebo of corn oil that included 0.6 g of linoleic acid daily.
Outcome Measurements: Cognitive measurement upon outcome included MMSE and cognitive portion of Alzheimer Disease Assessment Scale (ADAS).
Results: No statistical significant difference during 6 and 12 months for those with more advanced AD as revealed by MMSE and ADAS; however, a subgroup of mild dementia did show statistically significant treatment from MMSE scores over the duration of the study. The results found with the subgroup with mild dementia strongly suggest possibility of better cognitive performance and, perhaps, a role in “primary prevention of AD but not in treatment of manifest disease”.
Assessment: Despite lack of a cross-over trial included, this first-ever published randomized, double-bind, placebo-controlled study on treating AD with n-3 fatty acids presents valid data of excellent quality. The study, however, is limited in data on how differing amounts of n-3 fatty acids as well as differing ratios of EPA and DHA might have affected results. The researchers rightly suggest that more controlled intervention studies are needed to explore this area.
Reference: Freund-Levi Y, Eriksdotter-Jonhagen M, Cederholm T et al. Omega-3 fatty acid treatment in 174 patients with mild to moderate Alzheimer disease: OmegAD study: a randomized double-blind trial. Arch Neurol 2006;63:1402-8.