Skeletal muscle mass and function decline progressively from the fourth decade of life onwards, often culminating in sarcopenia and a concomitant loss of mobility and independence in older age. Recent estimates indicate that the excess health and social care costs associated with muscle weakness in the UK are approximately £2.5 billion per year. With the proportion of older adults (>65 years) predicted to increase substantially over the coming decades, there is an urgent need to develop effective interventions to preserve or enhance muscle mass and function.

Resistance exercise is the most efficacious strategy to counteract age-related declines in skeletal muscle mass and function. However, adherence to resistance exercise recommendations remains low, particularly among older adults, limiting its effectiveness at a population level. Consequently, nutritional interventions have attracted considerable interest as alternative or adjunctive strategies. Emerging evidence suggests that the long-chain n-3 polyunsaturated fatty acids (LCn-3 PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may represent a promising intervention for promoting healthy muscle ageing. EPA and DHA are obtained primarily from oily fish, yet population intakes are generally low, with a large proportion of individuals consuming insufficient amounts to achieve recommended levels.

Early studies in cell culture and animal models demonstrated that LCn-3 PUFA can stimulate muscle protein synthesis (MPS) and potentially increase muscle mass. Consistent with these findings, epidemiological studies in humans have reported positive associations between oily fish consumption and muscle strength, while acute physiological studies have shown that LCn-3 PUFA supplementation augments the MPS response under hyperinsulinaemic–hyperaminoacidaemic clamp conditions. More recently, chronic supplementation studies have demonstrated improvements in muscle mass and function in older adults following fish oil supplementation. Supporting these observations, our recent work in a larger cohort of older adults (n = 94) demonstrated that 6 months of krill oil supplementation increased grip strength, knee extensor maximal torque, muscle thickness and muscle quality. These findings also suggested that some of the functional benefits occurred independently of changes in muscle mass, alongside increases in the M-wave, raising the possibility that neural adaptations contribute to the observed improvements. Further work is required to determine the mechanisms underpinning these effects. There is also evidence that LCn-3 PUFA supplementation may enhance adaptations to resistance exercise training.

This presentation will review the mechanistic and clinical evidence supporting a role for LCn-3 PUFA in healthy muscle ageing and present our latest findings examining the effects of LCn-3 PUFA supplementation on MPS responses to protein ingestion and resistance exercise in older adults.