title: 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.
abstract: 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.
authors.affiliation: School of Health Sciences, Sansom Institute for Health Research, Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia. natalie.sinn@unisa.edu.au
authors.forename: Natalie
authors.initials: N
authors.lastname: Sinn
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Milte
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Street
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Buckley
authors.forename: Alison M
authors.initials: AM
authors.lastname: Coates
authors.forename: John
authors.initials: J
authors.lastname: Petkov
authors.forename: Peter R C
authors.initials: PR
authors.lastname: Howe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D003072:Cognition Disorders / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology / Q000523:psychology; D003863:Depression / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology / Q000523:psychology; D019587:Dietary Supplements / Q000032:analysis; D004281:Docosahexaenoic Acids / Q000032:analysis / Q000378:metabolism / Q000627:therapeutic use; D015118:Eicosapentaenoic Acid / Q000032:analysis / Q000378:metabolism / Q000627:therapeutic use; D004912:Erythrocytes / Q000378:metabolism; D056344:Executive Function; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000378:metabolism / Q000627:therapeutic use*; D005260:Female; D005395:Fish Oils / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000517:prevention & control*; D010352:Patient Dropouts; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D012720:Severity of Illness Index; D013064:Speech Disorders / Q000209:etiology / Q000517:prevention & control
chemical_list: D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid