title: Sex differences in the effect of fish-oil supplementation on the adaptive response to resistance exercise training in older people: a randomized controlled trial.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Institute of Medical Sciences and.
authors.forename: Mariasole
authors.initials: M
authors.lastname: Da Boit
authors.affiliation: Institute of Medical Sciences and.
authors.forename: Rachael
authors.initials: R
authors.lastname: Sibson
authors.affiliation: Institute of Medical Sciences and.
authors.forename: Selvaraj
authors.initials: S
authors.lastname: Sivasubramaniam
authors.affiliation: Exeter MR Research Centre, University of Exeter, Exeter, United Kingdom.
authors.forename: Judith R
authors.initials: JR
authors.lastname: Meakin
authors.affiliation: School of Sport, Exercise and Rehabilitation Sciences and.|Medical Research Council Arthritis Research United Kingdom Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Greig
authors.affiliation: Institute of Medical Sciences and.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Aspden
authors.affiliation: Institute of Medical Sciences and.
authors.forename: Frank
authors.initials: F
authors.lastname: Thies
authors.affiliation: Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom.
authors.forename: Stewart
authors.initials: S
authors.lastname: Jeromson
authors.affiliation: Faculty of Health Sciences and Sport, University of Stirling, Stirling, United Kingdom.
authors.forename: D Lee
authors.initials: DL
authors.lastname: Hamilton
authors.affiliation: School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom.|Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: John R
authors.initials: JR
authors.lastname: Speakman
authors.affiliation: School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom.
authors.forename: Catherine
authors.initials: C
authors.lastname: Hambly
authors.affiliation: Department of Clinical Pharmacology, School of Medicine, Flinders University, Adelaide, Australia; and.
authors.forename: Arduino A
authors.initials: AA
authors.lastname: Mangoni
authors.affiliation: Scottish Universities Environmental Research Centre, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Thomas
authors.initials: T
authors.lastname: Preston
authors.affiliation: Institute of Medical Sciences and stuart.gray@glasgow.ac.uk.
authors.forename: Stuart R
authors.identifier: 0000-0001-8969-9636
authors.initials: SR
authors.lastname: Gray
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000273:Adipose Tissue; D000368:Aged; D001823:Body Composition / Q000187:drug effects; D015992:Body Mass Index; D004041:Dietary Fats / Q000097:blood / Q000494:pharmacology*; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000494:pharmacology; D005260:Female; D005395:Fish Oils / Q000097:blood / Q000494:pharmacology*; D006801:Humans; D035002:Lower Extremity; D008297:Male; D009068:Movement; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D055070:Resistance Training; D012737:Sex Factors; D019415:Torque; D014280:Triglycerides / Q000097:blood
chemical_list: D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D014280:Triglycerides
keywords: aging; exercise; fatty acids; muscle; sarcopenia