2 RESEARCH ARTICLES
FISH OIL ANABOLIC FOR AGING POPULATION BUT NOT YOUNGER – 2014
Laurent Bannock @laurent_bannock
– Summary and conclusions (see slide) to @LeighBreen ‘s lecture on ‘fish oil and muscle building’ pic.twitter.com/lV6kdM7gE0
1. Fish oil supplementation (4g/d) enhances MTORC1 signaling and MPS response to nutrition in middle aged and older muscles
2. Chronic fish oil supplementation (1-2g/d) enhances strength and physical function in older adults
3. Mechanism of action = alleviating anabolic resistance?
4. EPA stimulates MTORC1 signalling and Muscle Protein Synthesis MPS in the presence of nutrients and may suppress Muscle Protein Breakdown MPB (To Be Determined in humans)
5. At least 4 weeks of supplementation (5g/day) required to see clear changes in muscle EPA/DHA content
6. Chronic fish oil supplementation does not enhance the MPS response to mechanical loading and/or protein feeding in young males
T. Churchward-Venne @churchwardvenne – 2014
1. Fish oil supplementation increases the anabolic effect of amino acids on skeletal muscle
2. A diet that shifts the omega 6 to 3 ratio in favour of omega 3 increases gains in muscle mass
3. Fish oil supplementation changes the fatty acid composition of skeletal muscle
Gordon I. Smith*, Philip Atherton†, Bettina Mittendorfer et al
– BSA, body surface area; CRP, C-reactive protein; DHA, docosahexaenoic acid; eEF2, eukaryotic elongation factor 2; EPA, eicosapentaenoic acid; FFM, fat-free mass; FSR, fractional synthesis rate; IL-6, interleukin-6; mTOR, mammalian target of rapamycin; MUFA, mono-unsaturated fatty acid; p70S6K, p70 S6 kinase; PUFA, polyunsaturated fatty acid; LCn−3PUFA, long-chain n−3 PUFA; SFA, saturated fatty acid; t-BDMS, t-butyldimethylsilyl; TNF-α, tumour necrosis factor-α; TTR, tracer/tracee ratio.
– Increased dietary LCn−3PUFA (long-chain n−3 polyunsaturated fatty acid) intake stimulates muscle protein anabolism in individuals who experience muscle loss due to aging or cancer cachexia
– It is not known whether LCn−3PUFAs elicit similar anabolic effects in healthy individuals.
– 8 wks of LCn−3PUFA supplementation (4 g of Lovaza®/day) in nine 25–45-year-old healthy subjects
– Evaluated the rate of muscle protein synthesis and the activation of elements of mTOR
– We measured the concentrations of protein, RNA and DNA in muscle to obtain indices of the protein synthetic capacity, translational efficiency and cell size.
1. Neither basal muscle protein fractional synthesis rate nor basal signalling element phosphorylation changed in response to LCn−3PUFA
2. But, the anabolic response to insulin and amino acid infusion was greater after LCn−3PUFA [i.e. the muscle protein fractional synthesis rate during insulin and amino acid infusion increased from 0.062±0.004 to 0.083±0.007%/h and the phospho-mTOR (Ser2448) and phospho-p70S6K (Thr389) levels increased by ∼50%].
3. The muscle protein concentration and the protein/DNA ratio (i.e. muscle cell size) were both greater after LCn−3PUFA supplementation.
– LCn−3PUFAs have anabolic properties in healthy young and middle-aged adults.