Reasons Why Omega-3 Polyunsaturated Fatty Acids Produce Mixed Results in Alzheimer's Disease Prevention Studies

Abnormal aging that epitomizes Alzheimer’s disease (AD) is accompanied by memory and cognitive deficits that interfere with daily activities. As scientists look for causes and means of treating AD, omega-3 (n-3) polyunsaturated fatty acids (PUFA) are gaining significance because of their importance in brain function and their depletion in AD [1]. A direct remedy is dietary supplementation studies that have unfortunately yielded mixed results. The perplexing question is why some studies have beneficial outcomes while others report no effects on AD-associated cognitive or memory problems. Factors that may account for these discrepancies include an incomplete understanding of PUFA metabolic pathways and inadequate study design. Most findings are based on epidemiological observations rather than placebo-controlled intervention studies. From examining these studies, it is evident that any improvement in the outcome must include a better understanding of omega-3 fatty acid metabolism, standardization of initial clinical observations, assurance of pharmaceutical quality of omega-3 supplements, and genetics based selection of study participants combined with quantifiable outcomes.