Omega 3s from fish/krill oil may lighten depression, help steady cognitive status in older adults

Effects of omega-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 randomized controlled trial
– Source: British Journal of Nutrition, Sep 20, 2011

By Natalie Sinn, et al.

[Note: DHA and EPA are both marine (fish/krill oil-based) sources of omega 3 fatty acids. They are omega-3 polyunsaturated fatty acids (PUFAs). LA (linoleic acid) is an omega-6 fatty acid.]

Depressive symptoms may increase the risk of progressing from mild cognitive impairment (MCI) to dementia. Consumption of omega-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 omega-3 PUFA, DHA and EPA, for depressive symptoms, quality of life (QOL) and cognition in elderly people with mild cognitive impairment.

We conducted a 6-month double-blind, randomized controlled trial. A total of 50 people aged >65 years with mild cognitive impairment 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 omega-6 PUFA linoleic acid (LA; 2.2 g/d; n 15).

Treatment allocation was by minimization 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 Geriatric Depression Scale 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 Geriatric Depression Scale 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 mild cognitive impairment. Increasing omega-3 PUFA intakes may reduce depressive symptoms and the risk of progressing to dementia.

This needs to be investigated in larger, depressed samples with mild cognitive impairment.

Source: British Journal of Nutrition, Sep 20, 2011. PMID: 21929835, by Sinn N, Milte CM, Street SJ, Buckley JD, Coates AM, Petkov J, Howe PR. School of Health Sciences, Sansom Institute for Health Research, Nutritional Physiology Research Centre, University of South Australia, GPO Box 2471, Adelaide, SA, Australia. (Email:

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