The researchers found that n-3 PUFA (EPA and/or DHA) supplementation could increase muscle mass by about 0.33 kg for the seniors receiving supplementation.
This is especially so when the n-3 PUFAs supplementation is more than 2g per day.
The supplementation of n-3 PUFA also shorten the time that subjects took in the timed “up and go test” by 0.3 secs, when compared to the controls.
Aside from muscle mass, supplementation of n-3 PUFAs for at least 24 weeks also increased the subjects’ walking speed, when compared to the controls.
The meta-analysis included 10 RCTs involving 552 seniors age 60 and above.
The study is in contrast to most of the current sarcopenia-related studies, which focus mainly on the effects of protein supplementation.
The meta-analysis was conducted by researchers from Taipei Medical University, National Yang-Ming University, and Taipei City Hospital, and findings were recently published in Nutrients.
They said that the findings were consistent with existing evidence on how lower EPA levels were linked to lower muscle mass, strength and function.
“Both animal and human studies have shown that n-3 PUFA supplementation enhances amino acid- and insulin-mediated increases in the rates of muscle protein syntheses.
“Several muscle synthesis mechanisms involving n-3 PUFAs have been proposed, including the induction of the mTORC1-p70S6K1 signaling pathway, which leads to increased protein synthesis and the downregulation of proteasome expression, thus suppressing muscle protein catabolism,” the researchers said.
To conduct the meta-analysis, they searched for RCTs that evaluated the effect of n-3 PUFAs through diet or supplementation on 1) skeletal muscle mass 2) muscle strength and 3) muscle performance in seniors.
RCTs available on PubMed, ClinicalTrials.gov, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Central Register of Controlled Trials (CENTRAL) as of Jul 31, 2018 were included into the meta-analysis.
The n-3 PUFAs studied in the meta-analysis included EPA, DHA from fish oil, ALA from flax oil or from the diet.
The n-3 PUFAs doses taken by the subjects ranged from 0.16 to 2.6g of EPA per day and 0 to 1.8 g of DHA per day. One of the studies also provided 14g of ALA per day.
Although n-3 PUFAs supplementation had increased muscle mass, this did not lead to an improvement in handgrip strength and one-repetition maximum strength of the leg.
In addition, the types of n-3 PUFAs consumed (dietary supplement or food sources) did not lead to significant differences in muscle mass outcomes.
Nonetheless, the researchers concluded that n-3 PUFA supplementation could be used to combat loss of muscle mass in seniors, but the optimal dose needs to be confirmed by a large-scale study.
“We suggest that n-3 PUFA supplementation has potential as an efficacious nutrition-based preventive or therapeutic strategy to combat the loss of muscle mass in the elderly.
“The optimal dosing pattern for n-3 PUFAs for sarcopenia-associated performance needs to be confirmed by a large-scale RCT in the future.”
Effects of Omega-3 Fatty Acids on Muscle Mass, Muscle Strength and Muscle Performance among the Elderly: A Meta-Analysis
Authors: Yuan-Hung Wang and et al