title: The effects of long-term omega-3 fatty acid supplementation on cognition and Alzheimer's pathology in animal models of Alzheimer's disease: a systematic review and meta-analysis.
abstract: To date, only a few randomized clinical trials (RCTs) have investigated the effects of omega-3 fatty acids (FA) on Alzheimer's disease (AD). Some of these studies demonstrated that patients with very mild AD or mild cognitive impairment benefit from omega-3 FA treatment, but none showed significant improvements in cognitive function in patients with moderate or advanced AD. All these RCTs had a relatively short duration of supplementation, however, and we hypothesized that this might be one of the reasons why no effects of omega-3 FA supplementation could be observed in patients with "moderate" or "advanced" AD. Animal studies offer better possibilities for controlled long-term supplementation than clinical studies. Therefore, we performed a systematic review (SR) and meta-analysis of the literature that focused on effects of the relatively long-term omega-3 FA supplementation (minimum period; 10% of average total lifespan) on cognitive impairment, amyloid-β pathology, and neuronal loss in animal models of AD. This SR shows that long-term omega-3 FA supplementation decreased the omega-6/omega-3 FA ratio and reduced the amount of amyloid-β in experimental animal models of AD. Omega-3 FA supplementation also improved cognitive function; this effect appeared larger in rats compared to mice, and in males compared to females. Moreover, omega-3 FA supplementation diminished the amount of neuronal loss, especially in female animals. The results of this SR indicate that it might be worthwhile to perform new clinical trials with long-term omega-3 FA supplementation in AD patients.
authors: Radboud University Nijmegen Medical Centre, Central Animal Laboratory and 3R Research Centre, Nijmegen, The Netherlands. C.Hooijmans@cdl.umcn.nl
authors: Carlijn R
authors: CR
authors: Hooijmans
authors: Pieternel C M
authors: PC
authors: Pasker-de Jong
authors: Rob B M
authors: RB
authors: de Vries
authors: Merel
authors: M
authors: Ritskes-Hoitinga
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy* / Q000473:pathology / Q000523:psychology; D000818:Animals; D003072:Cognition Disorders / Q000188:drug therapy* / Q000473:pathology / Q000523:psychology; D019587:Dietary Supplements; D004195:Disease Models, Animal; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D008297:Male; D051379:Mice; D051381:Rats; D013997:Time Factors
chemical_list: D015525:Fatty Acids, Omega-3