On the other hand, the four gram per day dose did not impact muscle-specific protein metabolism or mitochondrial function, according to findings published Nutrients.
“We found that 6 months of n3-PUFA supplementation modestly increased skeletal muscle strength in the absence of any measurable change in mitochondrial physiology,” wrote the researchers. “Notably, this cohort of older adults was healthy, independent and capable of performing activities of daily living, and did not exhibit the typical features of frailty or chronic inflammation.”
The research has significance for public health as we lose skeletal muscle mass and function as we age. Researchers have estimated that, after the age of 50, we lose 1-2% of our muscle mass each year. Strength declines as well, at a rate of 1.5% per year beginning at 50 years and accelerating to 3% after the age of 60.
The researchers recruited 63 older adults to participate in their randomized, double-blind, placebo-controlled trial. Volunteers received either placebo (corn oil) or the omega-3 supplement for six months. Both groups consumed four softgels per day, two in the morning and two in the evening with meals. The each omega-3 capsule contained 1,000-mg of concentrated fish oil providing approximately 675 mg EPA (20:5n–3) and 300 mg DHA (22:6n–3). The supplements are sold commercially as Ocean Blue Professional Omega-3 2100.
The data at the end of the study showed that the omega-3 group exhibited “modest but significant increases in muscle strength” of about 7.5%, compared to 3.1% in the placebo group.
“This increase appeared to be driven by improved muscle quality, as strength normalized to leg lean mass also increased in the n3-PUFA group,” wrote the researchers.
No changes in mitochondrial function were observed, said the researchers.
“Aging is commonly associated with decreased mitochondrial protein content as well as dysfunction at the level of the organelle, so it is worth noting that this cohort of older adults did not demonstrate the typical age-related deficits in mitochondrial function,” they explained. “Therefore, it is important to not generalize these results beyond the situation of healthy aging since we cannot rule out the possibility that n3-PUFA may enhance mitochondrial energy metabolism in other aging populations that exhibit more profound sarcopenia, frailty, and dysfunctional mitochondria.”
The researchers called for more studies to explore the potential benefits of omega-3 fatty acid supplementation on older people with co-morbidities, such as chronic inflammatory disease or sarcopenia.
2022, 14(17), 3537; doi: 10.3390/nu14173537
“A Randomized Trial of the Effects of Dietary n3-PUFAs on Skeletal Muscle Function and Acute Exercise Response in Healthy Older Adults”
Authors: H.E. Kunz et al.