Omega-3 fatty acids and vitamin D in immobilisation: Part B- Modulation of muscle functional, vascular and activation profiles

Abstract

ObjectivesThis study set out to determine whether two potential protein-sparing modulators (eicosapentaenoic acid and vitamin D) would modulate the anticipated muscle functional and related blood vessels function deleterious effects of immobilisation.DesignThe study used a randomised, double-blind, placebo-controlled design.SettingThe study took part in a laboratory setting.ParticipantsTwenty-four male and female healthy participants, aged 23.0±5.8 years.InterventionThe non-dominant arm was immobilised in a sling for a period of nine waking hours a day over two continuous weeks. Participants were randomly assigned to one of three groups: placebo (n=8, Lecithin, 2400 mg daily), omega-3 (ω-3) fatty acids (n=8, eicosapentaenoic acid (EPA); 1770 mg, and docosahexaenoic acid (DHA); 390 mg, daily) or vitamin D (n=8, 1,000 IU daily).MeasurementsIsometric and isokinetic torque, antagonist muscle co-contraction (activation profile), muscle fatigability indices, and arterial resting blood flow were measured before, at the end of the immobilisation period, and two weeks after re-mobilisation.ResultsMuscle elbow flexion and extension isometric and isokinetic torque decreased significantly with limb immobilisation in the placebo group (P<0.05). Despite no significant effect of supplementation, ω-3 and vitamin D supplementation showed trends (P>0.05) towards attenuating the decreases observed in the placebo group. There was no significant change in muscle fatigue parameters or co-contraction values with immobilisation and no effect of supplementation group (P>0.05). Similarly, this immobilisation model had no impact on the assessed blood flow characteristics. All parameters had returned to baseline values at the re-mobilisation phase of the study.ConclusionOverall, at the current doses, neither ω-3 nor vitamin D supplementation significantly attenuated declines in torque associated with immobilisation. It would appear that muscle function (described here in Part B) might not be as useful a marker of the effectiveness of a supplement against the impact of immobilisation compared to tissue composition changes (described in Part A).

Update on the Impact of Omega 3 Fatty Acids on Inflammation, Insulin Resistance and Sarcopenia: A Review

“…Accordingly to previous studies in the literature [ 9 ], in healthy subjects high dose omega 3 supplementation did not result in any appreciable effects on muscle metabolism parameters or in muscle mass and function under basal conditions or after upper limb immobilisation in the absence of an anabolic stimuli [ 46 , 47 , 48 ]. It is thought that omega 3 fatty acids increase the rate of muscle protein synthesis in response to feeding and to resistance exercise by stimulating the mTOR-p70s6k signalling pathway [ 58 ].…”

“…Healthy adults received 1770 mg EPA and 390 mg DHA, 1000 IU vitamin D, or placebo daily, for 2 weeks, and the non-dominant arm was immobilised in a sling for 9 waking hours a day [ 46 , 47 ]. No effect of supplementations was observed in muscle thickness and upper and lower arm girths, with a trend for a smaller reduction compared to placebo [ 47 ].…”

“…No effect of supplementations was observed in muscle thickness and upper and lower arm girths, with a trend for a smaller reduction compared to placebo [ 47 ]. Similarly, no effect of supplementations was observed in muscle elbow flexion and extension isometric and isokinetic torque, although there was a trend for an attenuated reduction compared to placebo [ 46 ]. Omega 3 supplementation with 2000 mg EPA and 1000 mg DHA was given daily to healthy active individuals, and it was compared with placebo for 12 weeks (Gerling et al, 2014).…”