background In patients who have had a myocardial infarction (mi), the n-3 polyunsaturated fatty acid status is low while the risk of depression has increased.
aim To assess whether plant-derived alpha-linolenic acid (ala) and fish fatty acids, eicosapentaenoic acid (epa) and docosahexaenoic acid (dha), would improve affective states in patients after mi.
method The Alpha Omega Trial is a randomised double-blind, placebo-controlled trial of n-3 fatty acids in patients aged 60 through 80 who had had a mi. Margarine spreads were used to deliver 400 mg/d epa-dha, 2 g/d ala, both epa-dha and ala, or placebo for 40 months using a 2×2 factorial design. A total of 4116 patients (85.1% of the total randomised 4837 patients; 79.2% men) were followed until 40 months for the endpoints depressive symptoms (15-item Geriatric Depression Scale) and dispositional optimism (a fouritem questionnaire [4Q] and Life Orientation Test-Revised [lot-r]) using a post-test only design.
results The four randomised groups did not differ for baseline characteristics. The average additional intake was 233 mg/d of epa, 155 mg/d of dha, and 1.9 g/d of ala in the appropriate groups. N-3 fatty acid supplementation significantly increased serum cholesteryl ester levels of ala by 69%, epa by 61%, and dha by 30%. Depressive symptoms or dispositional optimism didn’t differ between groups using n-3 fatty acids versus placebo after 40 months of follow-up. The standardised mean difference of depressive symptoms for epa-dha versus placebo was -0.01 (95% ci -0.08 to 0.05; p = 0.67) and for ala versus placebo -0.01 (95% ci -0.07 to 0.05; p = 0.69). In the randomised groups no significant differences in side-effects were found.
conclusion Among patients who have had a mi, low-dose epa-dha and ala supplementation did not affect depressive symptoms and dispositional optimism. Similar results were obtained for subgroups of patients using antidepressants or with a (family) history of depression.