A daily dose of fish oil increased the omega‐3 index in older adults and reduced their heart rate during a walking activity: A pilot study

Abstract

AbstractThis pilot study sought to determine whether a low, supplemental intake of fish oil would raise the Omega‐3 Index (O3I) and improve physical fitness in healthy older adults. Participants (70 ± 3 years) were randomised to 2 g/day of either sunola oil (control; n = 8, 62.5% female) (1700 mg/day oleic acid) or docosahexaenoic acid (DHA)‐rich fish oil (FO; n = 9, 55.6% female) [delivering 560 mg/day DHA and 140 mg/day eicosapentaenoic acid (EPA)] for 16 weeks. The O3I, physical fitness, 400 m walking speed and heart rate (HR) parameters were assessed. O3I was increased after FO (mean ± SD, control: pre 6.1 ± 0.8, post 5.9 ± 0.6; FO: pre 6.0 ± 0.6, post 8.3 ± 1.2 p < 0.05). Mean lowest overnight HR (control: pre 58 ± 6, post 58 ± 6; FO: pre 55 ± 6, post 52 ± 6 bpm, p < 0.05) and mean HR during fast walking (control: pre 120 ± 6, post 124 ± 7; FO: pre 122 ± 6, post 115 ± 6 bpm, p < 0.01) were reduced in the FO group without a change in walking speed (control: pre 1.55 ± 0.17, post 1.58 ± 0.20; FO: pre 1.59 ± 0.15, post 1.59 ± 0.18 m/s), HR variability or physical fitness. The changes in lowest resting HR and fast walking HR significantly correlated (inversely) with the changes in O3I. This nutritional approach of providing dietary achievable DHA offers a potential opportunity to reduce cardiovascular strain during physical activity in the older adult.