Journal Article

Effects of n-3 fatty acids, EPA v. DHA, on depressive symptoms, quality of life, memory and executive function in older adults with mild cognitive impairment: a 6-month randomised controlled trial

Coates, Alison M., Howe, Peter R. C., Buckley, Jonathan D., Street, Steven J., Milte, Catherine M., Sinn, Natalie, Petkov, John

2012

Overview

Depressive symptoms may increase the risk of progressing from mild cognitive impairment (MCI) to dementia. Consumption of n-3 PUFA may alleviate both cognitive decline and depression. The aim of the present study was to investigate the benefits of supplementing a diet with n-3 PUFA, DHA and EPA, for depressive symptoms, quality of life (QOL) and cognition in elderly people with MCI. We conducted a 6-month double-blind, randomised controlled trial. A total of fifty people aged >65 years with MCI were allocated to receive a supplement rich in EPA (1·67 g EPA+0·16 g DHA/d; n 17), DHA (1·55 g DHA+0·40 g EPA/d; n 18) or the n-6 PUFA linoleic acid (LA; 2·2 g/d; n 15). Treatment allocation was by minimisation based on age, sex and depressive symptoms (Geriatric Depression Scale, GDS). Physiological and cognitive assessments, questionnaires and fatty acid composition of erythrocytes were obtained at baseline and 6 months (completers: n 40; EPA n 13, DHA n 16, LA n 11). Compared with the LA group, GDS scores improved in the EPA (P = 0·04) and DHA (P = 0·01) groups and verbal fluency (Initial Letter Fluency) in the DHA group (P = 0·04). Improved GDS scores were correlated with increased DHA plus EPA (r 0·39, P = 0·02). Improved self-reported physical health was associated with increased DHA. There were no treatment effects on other cognitive or QOL parameters. Increased intakes of DHA and EPA benefited mental health in older people with MCI. Increasing n-3 PUFA intakes may reduce depressive symptoms and the risk of progressing to dementia. This needs to be investigated in larger, depressed samples with MCI.

• Publisher: Cambridge University Press
• Subject: Aged / Aged, 80 and over / Australia / Biological and medical sciences / Clinical trials / cognition / Cognition Disorders - blood / Cognition Disorders - diet therapy / Cognition Disorders - physiopathology / Cognition Disorders - psychology / Cognitive ability / dementia / Dementia disorders / Depression - blood / Depression - diet therapy / Depression - physiopathology / Depression - psychology / diet / Dietary supplements / Dietary Supplements - analysis / Docosahexaenoic Acids - analysis / Docosahexaenoic Acids - metabolism / Docosahexaenoic Acids - therapeutic use / Eicosapentaenoic Acid - analysis / Eicosapentaenoic Acid - metabolism / Eicosapentaenoic Acid - therapeutic use / elderly / erythrocytes / Erythrocytes - metabolism / Executive Function / fatty acid composition / Fatty acids / Fatty Acids, Omega-3 - analysis / Fatty Acids, Omega-3 - metabolism / Fatty Acids, Omega-3 - therapeutic use / Feeding. Feeding behavior / Female / Fish Oils - chemistry / Fish Oils - metabolism / Fish Oils - therapeutic use / Fundamental and applied biological sciences. Psychology / Human and Clinical Nutrition / Humans / linoleic acid / Male / Memory / Memory Disorders - etiology / Memory Disorders - prevention & control / Mental depression / mental health / Older people / omega-3 fatty acids / omega-6 fatty acids / Patient Dropouts / people / polyunsaturated fatty acids / Psychiatric Status Rating Scales / Quality of Life / questionnaires / randomized clinical trials / risk / Severity of Illness Index / Speech Disorders - etiology / Speech Disorders - prevention & control / Vertebrates: anatomy and physiology, studies on body, several organs or systems