Additionally, the study found improvements in inflammatory markers and triglycerides, highlighting “the promising effects of arginine and fish oil supplementation in managing sarcopenia in older adults”, the researchers in China wrote in the journal Frontiers in Nutrition.
Addressing sarcopenia in older age
Sarcopenia is a geriatric condition characterized by a progressive loss of muscle mass and function, affecting around 10% to 16 % of the elderly population worldwide.
Older adults with sarcopenia have a higher risk of adverse health outcomes, including falls and fractures, longer hospitalization, metabolic disorders, cognitive impairments and mortality.
Age-related physiological changes, such as down regulation of anabolic hormones and chronic inflammation, are key aspects in the development of sarcopenia.
The anti-inflammatory properties of omega-3 fatty acids and the anabolic potential of the aminoacid L-arginine have shown therapeutic promise in clinical research for targeting the pathwaysinvolved in sarcopenia.
“Emerging evidence suggests a synergistic relationship between fish oil and arginine, with studies demonstrating that fish oil can enhance arginine bioavailability and activity,” the researchers wrote.
They noted that the beneficial mechanisms may include arginine’s ability to promote muscle protein synthesis and to enhance nitric oxide production, thereby restoring skeletal muscle function. EPA and DHA have been linked to musculoskeletal health, having the potential to upregulate key signaling pathways, “enhance protein translation and inhibit muscle protein degradation, thereby improving muscle protein synthesis efficiency.”
Study details
Researchers randomly assigned 29 adults with sarcopenia over the age of 60 to consume 14 grams of arginine and 6 grams of fish oil (DHA 1.26 grams, EPA 1.92 grams) or a placebo daily for 12 weeks.
At the start and end of the trial, the researchers measured the participants’ handgrip strength, gait speed, 5-time chair stand test and skeletal muscle index (SMI). As secondary outcomes, they also assessed inflammatory markers, nutritional status, blood lipid levels, frailty, physical activity and sleep quality.
“When the outcome of measurements was compared between intervention groups, it was found that the gait speed and grip strength were significantly higher in the Arg + fish oil group than in the placebo group at the end of the trial,” the researchers wrote.
Regarding inflammatory markers, the results revealed that “TNF-α and IL-6 were significantly lower in the Arg + fish oil group than in the placebo group at the end of the trial.”
The researchers reported no significant differences in nutritional risk status but significant improvement in triglycerides in the arginine and fish oil group.
The Physical Activity Scale for the Elderly (PASE) and the FRAIL scale, which assesses fatigue, resistance, ambulation, illness and loss of weight, showed improvements in the intervention group compared with the placebo group.
“However, our study did not observe significant improvements in muscle mass, possibly due to the complex pathogenesis of sarcopenia,” the researchers wrote.
They called for further large-scale, multicenter studies to confirm their results and explore thelong term benefits of the supplements.
Source: Frontiers in Nutrition. doi: 10.3389/fnut.2026.1763219. “Twelve-week combined arginine and fish oil supplementation is associated with reduced sarcopenia severity: a randomized, double-blind, placebo-controlled study”. Authors: W. Yuan et al.
