Dietary recommendations have been made for n-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) to achieve nutrient adequacy and to prevent and treat cardiovascular disease. These recommendations are based on a large body of evidence from epidemiologic and controlled clinical studies. The n-3 fatty acid recommendation to achieve nutritional adequacy, defined as the amount necessary to prevent deficiency symptoms, is 0.6-1.2% of energy for ALA; up to 10% of this can be provided by EPA or DHA.

To achieve recommended ALA intakes, food sources including flaxseed and flaxseed oil, walnuts and walnut oil, and canola oil are recommended. The evidence base supports a dietary recommendation of approximately 500 mg/d of EPA and DHA for cardiovascular disease risk reduction. For treatment of existing cardiovascular disease, 1 g/d is recommended. These recommendations have been embraced by many health agencies worldwide.

A dietary strategy for achieving the 500-mg/d recommendation is to consume 2 fish meals per week (preferably fatty fish).

Foods enriched with EPA and DHA or fish oil supplements are a suitable alternate to achieve recommended intakes and may be necessary to achieve intakes of 1 g/d.

PMID: 16841863

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