January 10, 2019
Fish oil supplementation can slow muscle loss during periods of immobilization, a study has found. The study was published online January 10 in the FASEB Journal.
"We are the first to show that n-3 fatty acid supplementation attenuates decrements in skeletal muscle size in response to unilateral leg immobilization in women," write Chris McGlory, PhD, from McMaster University, Ontario, Canada, and colleagues.
Researchers enrolled 20 healthy young women (age range, 19-31 years) who were recreationally active (ie, active but engaging in structured exercise 2 days/week or fewer). They randomly assigned women to two groups: one group received an omega-3 fatty acid (fish oil) supplement (active group) and the other group received a sunflower oil supplement (control group).
Participants in the fish oil group consumed 2.97 g eicosapentaenoic acid (EPA) and 2.03 g docosahexaenoic acid (DHA). Both groups consumed the supplements for 4 weeks, at which time all participants had one of their legs immobilized for 2 weeks in a knee brace. During the immobilization phase, all participants were provided with all food to control protein intake to 1.0 g/kg body mass/day. Following the immobilization phase, participants then returned to normal activity for a 2-week recovery period. Leg muscle volume, strength, mass, and protein synthesis (based on blood and skeletal muscle samples) were evaluated before and after immobilization as well as after the recovery period.
Participants in the fish oil group lost significantly less muscle mass during immobilization compared with those in the control group. Further, whereas a significant decline in muscle volume was noted in both groups (P < 0.01), only those in the fish oil group regained full skeletal muscle volume following a return to regular daily activity.
These findings highlight "the potential efficacy of n-3 fatty acid intake to mitigate disuse-induced skeletal muscle atrophy," write McGlory and colleagues.
The authors acknowledge that because the study enrolled only young women, these findings cannot be extrapolated to other populations such as men or older adults and that further studies are needed.
"The practical implication of these findings is that n-3 supplementation may be a viable strategy to offset muscle atrophy and promote recovery following periods of muscle disuse in humans, such as elective surgery," conclude the authors.
Funding for this study was provided through an award from the Canadian Institutes of Health. The authors have disclosed no relevant financial relationships.