Omega-3 dietary fatty acid status of healthy older adults in Tasmania, Australia: An observational study

Objectives: To determine the dietary and supplement intake of omega-3 (n-3) polyunsaturated fatty acids (PUFA) of older Tasmanian adults; their plasma n-3 PUFA status and the relationship between n-3, PUFA intake and plasma status.

Design: Cross-sectional study.

Setting: Launceston and surrounding regions Tasmania, Australia.

Participants: Seventy-three community-dwelling older adults: 23 men aged 70 ± 6.1 years and 50 women aged 70 ± 6.7 years.

Measurements: A validated, semi-quantitative food frequency questionnaire estimated dietary PUFA intake. The plasma phospholipid fraction of venous blood samples was analysed for fatty acid content. Anthropometric data was recorded.

Results: Thirty-five participants (48%) regularly ingested (a fish oil supplement. Their plasma n-3 PUFA profile contained significantly more eicosapentaenoic acid (EP odds ratio 3.14; 95% CI 1.37% to 7.30%; p < 0.05) and docosahexaenoic acid (DHA) (odds ratio 2.64; 95% CI) 1.16% to 6.01%; p < 0.05) than non-supplement users. Fish and meat were the main dietary sources of n-3 PUFAs. Participants most commonly consumed fish 3-4 times per week. Significant associations of dietary α-linolenic acid (ALA), EPA, docosapentaenoic acid (DPA) and DHA with plasma n-3 PUFAs were noted but not always between dietary and plasma counterparts.

Conclusion: Without the use of fish oil supplements, most study participants were unable to meet the recommended daily intake of 0.5g EPA and DHA combined; however, the plasma n-3 PUFA profile of non-supplement-users was still robust compared to other Australian and overseas studies.