Omega-3 Fatty Acid Treatment in 174 Patients With Mild to Moderate Alzheimer Disease: OmegAD Study
Fruend-Levi Y, et al. Arch. Neurol., 63: 1402-1408 (2006).
Department of Neurobiology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
Patients with an established diagnosis of Alzheimer Disease (AD) with varying degrees of severity participated in a randomized, double-blind, placebo-controlled study. Subgroups of AD patients (204 patients with a mean age of 74 years +/- 9 years) included those with mild or more advanced AD. The level of cognitive performance was based on MMSE scoring such that patients with very mild AD were determined by higher MMSE (Mini-Mental State Examination) scores of >27 points. Patients received four 1-g capsules daily each containing 430 mg of DHA and 150 mg of EPA) or a placebo oil for 6 months followed by 6 months of open treatment with omega-3 supplementation in all patients. The total daily intake of DHA/EPA (combined) was 2320 mg (1720 mg EPA plus 600 mg DHA). Patients underwent evaluations including cognitive functioning using the MMSE at baseline and at 6 and 12 months. In contrast to the control group, wherein a significant reduction between baseline and 6 months later for both ‘Delayed word recall' and ‘Attention' was observed, the omega-3 treated group showed no significant decline. These beneficial effects in the treatment group were observed in those patients with very mild AD (MMSE >27 points) but not in AD patients with more advanced AD (no delay in the rate of cognitive decline for those with mild to moderate AD).
The authors suggest that the mechanisms by which omega-3 fatty acids (DHA/EPA) could interfere with pathophysiologic features of AD may include anti-inflammatory effects.
Dr. Holub's Comments:
This study represents the first reported randomized, double-blind, placebo-controlled study using supplemental DHA/EPA in patients with AD. Previous epidemiological studies have suggested that those with higher intakes of fish containing DHA omega-3 fatty acid over extended time periods may be at a significantly lower risk for developing AD (see, for example, Morris et al., Arch. Neurol., 60:940-946, 2003.). It is possible that higher intakes of DHA/EPA may play a preventive role in delaying the onset of AD as well as being of potential benefit in those with very mild and early stage disease. However, DHA/EPA supplementation may not be of clinical benefit when initiated in those presenting with a more advanced stage of AD. This present study is most deserving of follow-up clinical trials before fish oil/concentrates can be routinely employed in clinical settings for AD patients.