Sex differences in the effect of fish-oil supplementation on the adaptive response to resistance exercise training in older people: a randomized controlled trial

Da Boit, M. et al. (2017) Sex differences in the effect of fish-oil supplementation on the adaptive response to resistance exercise training in older people: a randomized controlled trial. American Journal of Clinical Nutrition, 105(1), pp. 151-158. (doi: 10.3945/ajcn.116.140780) (PMID:27852617) (PMCID:PMC5183731)

Abstract

Background: Resistance exercise increases muscle mass and function in older adults, but responses are attenuated compared with younger people. Data suggest that long-chain n–3 polyunsaturated fatty acids (PUFAs) may enhance adaptations to resistance exercise in older women. To our knowledge, this possibility has not been investigated in men. Objective: We sought to determine the effects of long-chain n–3 PUFA supplementation on resistance exercise training–induced increases in muscle mass and function and whether these effects differ between older men and women. Design: Fifty men and women [men: n = 27, mean ± SD age: 70.6 ± 4.5 y, mean ± SD body mass index (BMI; in kg/m2): 25.6 ± 4.2; women: n = 23, mean ± SD age: 70.7 ± 3.3 y, mean ± SD BMI: 25.3 ± 4.7] were randomly assigned to either long-chain n–3 PUFA (n = 23; 3 g fish oil/d) or placebo (n = 27; 3 g safflower oil/d) and participated in lower-limb resistance exercise training twice weekly for 18 wk. Muscle size, strength, and quality (strength per unit muscle area), functional abilities, and circulating metabolic and inflammatory markers were measured before and after the intervention. Results: Maximal isometric torque increased after exercise training to a greater (P < 0.05) extent in the long-chain n–3 PUFA group than in the placebo group in women, with no differences (P > 0.05) between groups in men. In both sexes, the effect of exercise training on maximal isokinetic torque at 30, 90, and 240° s−1, 4-m walk time, chair-rise time, muscle anatomic cross-sectional area, and muscle fat did not differ (P > 0.05) between groups. There was a greater (P < 0.05) increase in muscle quality in women after exercise training in the long-chain n–3 PUFA group than in the placebo group, with no such differences in men (P > 0.05). Long-chain n–3 PUFAs resulted in a greater decrease (P < 0.05) than the placebo in plasma triglyceride concentrations in both sexes, with no differences (P > 0.05) in glucose, insulin, or inflammatory markers. Conclusion: Long-chain n–3 PUFA supplementation augments increases in muscle function and quality in older women but not in older men after resistance exercise training. This trial was registered at clinicaltrials.gov as NCT02843009.

• Item Type: Articles
• Additional Information: Supported by the Biotechnology and Biological Sciences Research Council.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Preston, Professor Tom and Gray, Professor Stuart
• Authors: Da Boit, M., Sibson, R., Sivasubramaniam, S., Meakin, J. R., Greig, C. A., Aspden, R. M., Thies, F., Jeromson, S., Hamilton, D. L., Speakman, J. R., Hambly, C., Mangoni, A. A., Preston, T., and Gray, S. R.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health; College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: American Journal of Clinical Nutrition
• Publisher: Oxford University Press
• ISSN: 0002-9165
• ISSN (Online): 1938-3207
• Published Online: 16 November 2016
• Copyright Holders: Copyright © 2017 American Society for Nutrition
• First Published: First published in American Journal of Clinical Nutrition 105(1): 151-158
• Publisher Policy: Reproduced under a Creative Commons License