Study under review: Factors influencing the efficacy of nutritional interventions on muscle mass in older adults: a systematic review and meta-analysis
Loss of muscle mass during old age, also called sarcopenia, is associated with all-cause mortality, fall and fracture risk, and some disease states, like nonalcoholic fatty liver disease. It is one of the most important modifiable risk factors of all-cause mortality and disease. Sarcopenia is multifactorial, but is greatly affected by malnutrition, amount and type of physical activity, and prolonged immobilization. All of these factors, combined, accentuate the loss of muscle mass and function, reducing the quality of life for elderly people.
One of the ways in which researchers are trying to combat sarcopenia is by using nutritional interventions that either prevent the loss of, or even increase, muscle mass. Whereas the molecular pathways that are involved are not completely understood, muscle mass is maintained by the balance between muscle protein synthesis (the creation of new muscle proteins) and breakdown (the degradation of muscle proteins). Resistance exercise is the most potent way of stimulating muscle growth, but supplementing dietary protein (and amino acids) can also help. Hence, supplementation with amino acids and/or protein might help combat sarcopenia. In addition, some other popular supplements that can theoretically modulate this balance may offer benefits. The way in which these supplements are consumed, including the type of supplement, dose, frequency, timing, duration and adherence, may be key to obtaining the desired effects.
The authors of the current systematic review and meta-analysis evaluated the effects of these parameters on muscle mass in older adults.
Sarcopenia, the loss of muscle mass during old age, is an important risk factor for all-cause mortality and disease in elderly people. In addition to resistance exercise, nutrition plays an important role, as it can modulate the muscle protein balance. However, the efficacy of nutritional supplements that could provide benefits in the context of sarcopenia depend on factors like type, dose, frequency, timing, duration and adherence.
Other Articles in Issue #75 (January 2021)
Safety Spotlight: Women and creatine
The effects of creatine are quite well studied, but its sex-specific safety profile hasn't been. Besides some non-serious side effects, creatine seems safe for women, but more work needs to understand creatine's effects during pregnancy.
The effects of increased protein intake on overall energy intake in older adults
Boosting protein intake may help stave off the loss of muscle strength and function that can come with age. But does increasing protein affect energy intake in older adults as well? We cover a recent meta-analysis that explored this question.
Sugar Wars, Episode 6: The Return of the Fructose
How does fructose affect cardiometabolic risk markers calorie-for-calorie compared to glucose or sucrose? This recent meta-analysis aimed to find out.
Interview: Cyriac Abby Philips, MBBS, MD, DM (Hepatology)
In this interview, we pick Dr. Philips' brain about the basics of Ayurveda, its safety, and the story behind a recently retracted paper he was involved with detailing a case of acute liver failure and death in a patient who was taking supplements.
Deep Dive: Comparing the efficacy of diet, exercise, and lifestyle modifications for controlling childhood obesity
This meta-analysis looked at what lifestyle interventions work best for children with overweight and obesity, and how much of a role parental involvement played.
Deep Dive: Do Low-Carb Diets Stoke the Metabolic Fire?
This meta-analysis concluded that longer-term low-carb dieters feel the metabolic burn, but some methodological concerns may douse this flame a bit.
Deep Dive: Evaluating the relationship between training status and optimal protein intake
According to this recent meta-analysis, whether or not more protein is better for lean body mass may come down to resistance training status.