Supplementation with dietary ω-3 mitigates immobilization-induced reductions in skeletal muscle mitochondrial respiration in young women.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 30970218 · doi:10.1096/fj.201900095R
What was done
Healthy young women (n = 20, age 22 ± 3 years) were randomized to receive either control (n = 9) or omega-3 supplementation (n = 11; 3 g EPA and 2 g DHA daily) for 4 weeks prior to and during 2 weeks of single-limb immobilization. Muscle biopsies were performed before immobilization and at days 3 and 14 of immobilization to assess mitochondrial respiration, H2O2 emission, and markers of ADP transport and lipid metabolism.
What was found
In the control group, 3 days of immobilization reduced ADP-stimulated mitochondrial respiration by ~20% without changes in ADP sensitivity or mitochondrial protein abundance; at 14 days, respiration remained reduced and mitochondrial proteins were reduced by ~20%. Omega-3 supplementation prevented both the reduction in mitochondrial respiration and the loss of mitochondrial content across the 14 days. Neither immobilization nor supplementation altered mitochondrial H2O2 emission (with or without ADP), cellular redox markers, lipid-supported respiration, or lipid metabolic proteins.
Why it matters
The findings demonstrate that disuse-induced mitochondrial respiration defects occur rapidly before protein loss and that high-dose omega-3 supplementation can preserve mitochondrial oxidative phosphorylation capacity during limb immobilization.
Limits
The study had a small sample size (n = 20) and included only healthy young females, limiting direct translation to older populations, males, or clinical patients experiencing systemic disuse or illness-related muscle wasting.
Cited by
- supports In Dr. McGlory's 2019 study, participants received a total dose of 5 grams of omega-3 per day.
- supports Graham Holloway showed that feeding omega-3s to younger people alters ADP sensitivity and ADP-stimulated respiration in human skeletal muscle mitochondria.