Omega-3 fatty acid treatment in 174 patients with mild to moderate Alzheimer disease: OmegAD study: a randomized double-blind trial.
BACKGROUND
Epidemiologic and animal studies have suggested that dietary fish or fish oil rich in omega-3 fatty acids, for example, docosahexaenoic acid and eicosapentaenoic acid, may prevent Alzheimer disease (AD).


OBJECTIVE
To determine effects of dietary omega-3 fatty acid supplementation on cognitive functions in patients with mild to moderate AD.


METHODS
Randomized, double-blind, placebo-controlled clinical trial.


METHODS
Two hundred four patients with AD (age range [mean +/- SD], 74 +/- 9 years) whose conditions were stable while receiving acetylcholine esterase inhibitor treatment and who had a Mini-Mental State Examination (MMSE) score of 15 points or more were randomized to daily intake of 1.7 g of docosahexaenoic acid and 0.6 g of eicosapentaenoic acid (omega-3 fatty acid-treated group) or placebo for 6 months, after which all received omega-3 fatty acid supplementation for 6 months more.


METHODS
The primary outcome was cognition measured with the MMSE and the cognitive portion of the Alzheimer Disease Assessment Scale. The secondary outcome was global function as assessed with the Clinical Dementia Rating Scale; safety and tolerability of omega-3 fatty acid supplementation; and blood pressure determinations.


RESULTS
One hundred seventy-four patients fulfilled the trial. At baseline, mean values for the Clinical Dementia Rating Scale, MMSE, and cognitive portion of the Alzheimer Disease Assessment Scale in the 2 randomized groups were similar. At 6 months, the decline in cognitive functions as assessed by the latter 2 scales did not differ between the groups. However, in a subgroup (n = 32) with very mild cognitive dysfunction (MMSE >27 points), a significant (P<.05) reduction in MMSE decline rate was observed in the omega-3 fatty acid-treated group compared with the placebo group. A similar arrest in decline rate was observed between 6 and 12 months in this placebo subgroup when receiving omega-3 fatty acid supplementation. The omega-3 fatty acid treatment was safe and well tolerated.


CONCLUSIONS
Administration of omega-3 fatty acid in patients with mild to moderate AD did not delay the rate of cognitive decline according to the MMSE or the cognitive portion of the Alzheimer Disease Assessment Scale. However, positive effects were observed in a small group of patients with very mild AD (MMSE >27 points).
Freund-Levi
Yvonne
Y
Department of Neurobiology, Caring Sciences and Society, Section of Clinical Geriatrics, Karolinska University Hospital Huddinge, Stockholm.
Eriksdotter-Jönhagen
Maria
M
Cederholm
Tommy
T
Basun
Hans
H
Faxén-Irving
Gerd
G
Garlind
Anita
A
Vedin
Inger
I
Vessby
Bengt
B
Wahlund
Lars-Olof
LO
Palmblad
Jan
J
D000368:Aged; D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D003072:Cognition Disorders / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D018450:Disease Progression; D004311:Double-Blind Method; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000627:therapeutic use; D015990:Placebo Effect; D016896:Treatment Outcome
D015525:Fatty Acids, Omega-3; D018696:Neuroprotective Agents