Direct quantitation of omega-3 fatty acid intake of Canadian residents of a long-term care facility

Abstract

An increased dietary intake of n-3 highly unsaturated fatty acids (HUFA; ≥20 carbons, ≥3 carbon–carbon double bonds), particularly eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), is associated with the decreased risk and incidence of several morbidities afflicting the elderly, including cognitive decline, dementia, rheumatoid arthritis, and macular degeneration. In this study, the dietary intake and blood levels of fatty acids were directly determined in residents of a retirement home or assisted living phase of a continuum of care facility for Canadian seniors. Finger-tip-prick blood samples, 3-day food duplicates, and 3-day food records were collected. The fatty acid composition of food duplicates and blood was determined by gas chromatography. Fifteen participants (7 male, 8 female; 87.1 ± 4.8 years of age) completed the protocol. The daily intake of EPA and DHA combined, determined directly, was 70 mg (95% CI, 41–119) or 0.036% of total energy (95% CI, 0.022–0.058). In finger-tip-prick blood, the percent of n-3 HUFA in total HUFA of whole blood, a biomarker of n-3 polyunsaturated fatty acid status, was 28.8 ± 5.2%. Correlations between daily n-3 HUFA intake and n-3 HUFA in blood were not significant (r = 0.14; n = 15), but became significant after the removal of 2 participants who appeared to consume fish irregularly (r = 0.59; n = 13). The n-3 HUFA intake and corresponding n-3 HUFA blood levels of Canadian long-term care residents are lower than levels estimated to prevent several morbidities associated with aging.