Table 1

Dietary sources of fatty acids

Foods and ingredients

Fatty acids contained in the foods


Fish and/or fish oil

Long chain n3 PUFAs such as EPA (C20:5n-3) and DHA (C22:6n-3)

EPA and DHA are the beneficial n3 PUFAs

Flaxseed and canola oil

The shorter chain n3 PUFA ALA

ALA is converted to EPA or DHA after ingestion, but not very efficiently. However, it can still provide a useful dietary source of EPA and DHA precursor. Whether it has a direct beneficial effect is unknown

Olive and canola oil

The MUFA OA (C18:1n-9)

OA has a neutral effect on n-3 PUFA metabolism and incorporation into tissues; therefore, it provides a useful 'background' dietary fat for maximizing n3 tissue content from dietary n3 PUFAs

Sunflower, peanut, soybean and cottonseed oil

The n6 PUFA LA (C18:2n-6)

Intake in modern Western diets is generally high and far in excess of what is required to prevent deficiency. Dietary LA can decrease conversion of dietary ALA to tissue EPA and can decrease tissue levels of EPA and DHA. LA is a precursor of AA (C20:4n-6), which is a metabolic antagonist of EPA

AA, arachidonic acid; ALA, α-linolenic acid; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; LA, linoleic acid; MUFA, monounsaturated fatty acid; OA, oleic acid; PUFA, polyunsaturated fatty acid.

Cleland et al. Arthritis Research & Therapy 2006 8:202   doi:10.1186/ar1876