Molecular Mechanisms, Physiological Effects, Gut Microbiota Interplay and Nutritional Strategies of Anthocyanins as Modulators of Muscle Protein Synthesis: A Narrative Review.

PURPOSE OF REVIEW: In this review we examine the role of anthocyanins-bioactive flavonoids found in colorful fruits and vegetables-in modulating muscle protein synthesis (MPS). We aim to elucidate the underlying molecular mechanisms, including the activation of anabolic pathways such as PI3K/Akt/mTOR and AMPK, while also highlighting the influence of gut microbiota on anthocyanin bioavailability and subsequent muscle metabolic responses. The goal is to provide nutritionists, clinicians, and sports scientists with a comprehensive understanding of how anthocyanins can be leveraged to enhance muscle recovery, attenuate sarcopenia, and optimize exercise performance.

RECENT FINDINGS: Anthocyanins can stimulate key signaling cascades associated with MPS, notably by enhancing the phosphorylation of mTOR and its downstream effectors, thereby promoting protein translation and muscle repair. Clinical and preclinical evidence suggests that these compounds not only reduce exercise-induced muscle damage and inflammation but also improve insulin sensitivity and anabolic signaling. Furthermore, interactions with the gut microbiota result in the formation of bioactive metabolites that may further augment the muscle protein synthesis process. Despite these promising results, challenges remain regarding optimal dosing, bioavailability, and interindividual variability in response to supplementation. The review consolidates current evidence positioning anthocyanins as promising dietary bioactives for muscle health. Their dual role in modulating both direct molecular pathways and gut microbiota interactions underscores their potential in enhancing muscle protein synthesis and recovery. However, further research is essential to standardize supplementation protocols, improve bioavailability, and fully understand the synergistic effects of other nutrients. These insights pave the way for targeted nutritional strategies aimed at improving muscle function and mitigating age-related muscle decline.