The loss of muscle mass, which inevitably occurs with age and at a greater speed later in life, is considered a clinical concern, especially due to increased risk of disease outcomes, a reduced quality of life, and a greater risk of injury. Researchers believe that there are a wide variety of nutritional interventions which could play some role in slowing down this process, and, in turn, there are likely several nutritional deficiencies which could create a greater risk for sarcopenia, the impaired physical function associated with age-related muscle loss.
 
According to a cross-sectional study, using data obtained from the Korean National Health and Nutrition Examination Survey, higher potassium intake was associated with a reduced rate of lost muscle mass in men, but not in women. Notably, loss of muscle mass is thought to be faster in men than in women, which may be mainly attributed to hormonal factors, the authors of the study wrote. While potassium doesn’t appear to have a direct impact on these hormonal factors, it may hold several beneficial effects on the preservation of muscle mass, bone density, and insulin sensitivity.
 
“The proposed methods to prevent a loss of muscle mass in the elderly are mainly protein intake and exercise,” the researchers wrote. “However, there have been little evidence of the effectiveness of other dietary approaches on muscle mass. Although some studies show an association between the intake of minerals, such as calcium and magnesium, and muscle mass, there are few studies on the role of potassium intake on muscle mass.”
 
The national survey, which recruited 16,558 participants, included data on daily food intake, which was acquired using a 24-hour recall method. Appendicular skeletal muscle mass was calculated using X-ray absorptiometry, and researchers defined low muscle mass as under 7 kg per square meter for men, and below 5.4 kg per square meter for women.
 
In men 19 years and older, higher potassium intake was associated with lower odds for low muscle mass, with the top for quintiles seeing a range of 22-42% reduced risk for definitively low muscle mass compared to the bottom quintile of potassium consumption.
 
The authors of the study identified a few mechanisms of action by which potassium might be benefitting the study population in such a way. First, potassium has been used successfully in the treatment of metabolic acidosis, a kidney disease which causes protein-energy wasting (diets high in meats and grains can cause a low-grade version of this disease to occur). Additionally, potassium’s evidenced relationship with insulin sensitivity and inflammation may have something to do with the protective effect, as insulin resistance in patients without diabetes is associated with impaired insulin signaling in muscle cells, and low potassium intake is associated with a greater amount of free radical synthesis.
 
Why the benefit of potassium on muscle loss presented itself as sex-specific, however, remains unclear, the authors of the study said.