A recent review published in Food & Function explored the effects of coffee and its rich array of bioactive components on the well-being of skeletal muscle. This comprehensive analysis sought to unravel how various compounds, ranging from the widely known caffeine to the less familiar trigonelline, influence fundamental biological processes governing muscle health, including NAD+ metabolism, glucose absorption, muscle development, and the prevention of frailty.
Coffee, a globally cherished beverage, is not only appreciated for its stimulating properties and diverse flavors but also recognized for its potential contributions to health. It is a significant source of beneficial compounds such as caffeine, hydroxycinnamic acids, trigonelline, and diterpenes, many of which possess anti-inflammatory and antioxidant qualities. While regular coffee intake has been associated with a reduced risk of various conditions, including specific cancers, cardiovascular diseases, type 2 diabetes, and neurodegenerative disorders, its precise impact on skeletal muscle health has remained largely unexplored.
To address this knowledge gap, researchers undertook a systematic review of scientific literature, encompassing studies on humans, animals, and in vitro models. The review specifically focused on research published from 2014 to 2025, investigating the effects of coffee, its extracts, or its primary bioactive compounds on skeletal muscle. Excluded from the analysis were studies centered on sports performance or ergogenic effects, as well as reviews, meta-analyses, and other non-primary research formats. Out of over 21,000 initial records, 54 studies were deemed suitable for inclusion. These comprised 21 in vitro experiments, 19 animal studies, 13 human investigations, and one study that integrated all three research approaches. In vitro studies primarily utilized murine muscle cell lines, with only a handful involving human muscle cells or myotubes. Ferulic acid emerged as the most frequently studied phenolic compound in these in vitro contexts, showing promise in enhancing myoblast proliferation and differentiation, and influencing muscle fiber type. Conversely, some in vitro studies indicated that caffeine, at high concentrations, might negatively affect myotube diameter and protein synthesis. Trigonelline was observed to elevate NAD+ levels in muscle cells, while cafestol demonstrated an ability to boost insulin-stimulated glucose uptake, mirroring the effects of certain anti-diabetic medications. Animal studies revealed varied results, with some suggesting that coffee supplementation could increase muscle weight and strength, and improve glucose metabolism in specific models. Human studies, predominantly observational, hinted at positive correlations between higher coffee intake and increased appendicular skeletal muscle mass, as well as reduced risks of functional impairment and frailty in older adults. However, one clinical trial indicated that favorable changes in body composition might be more attributable to fat loss rather than a direct increase in lean mass.
While the existing body of evidence suggests that coffee and its constituents may play a role in modulating biological pathways crucial for skeletal muscle metabolism, definitive conclusions cannot yet be drawn. The majority of human research remains observational, and many preclinical studies employ isolated compounds or dosages that may not accurately reflect typical coffee consumption patterns. Therefore, further long-term intervention studies are essential. These studies should feature clearly defined exposures and validated measures of skeletal muscle health to conclusively determine the clinical significance of coffee and its bioactive compounds in humans, ultimately paving the way for evidence-based recommendations for muscle wellness and longevity.