Pursuing muscle mass increase and longevity simultaneously is a challenging task. Activating mTORC1, necessary for muscle protein synthesis, can potentially shorten lifespan. Here, we explore the latest research on balancing these goals.
mTORC1 and Muscle Growth
mTORC1 is crucial for muscle protein synthesis but excessive activation may reduce lifespan. EPA and arginine can promote muscle protein synthesis with minimal impact on mTORC1. Training also activates mTORC1, necessitating a balance of benefits and risks.
The Impact of Fasting
Short-term fasting suppresses mTORC1 and promotes autophagy, but prolonged fasting may lead to muscle breakdown. During fasting, the transcription factor FOXO1 activates gluconeogenesis and fat breakdown but also increases muscle catabolism.
The Role of FOXO1
FOXO1 enhances muscle breakdown and BCAA utilization for energy during fasting. It also activates the fat breakdown enzyme ATGL. Vitamin D can suppress FOXO1, but fasting increases Sirt1, which enhances FOXO1 and contributes to longevity.
Insulin and FOXO1
Insulin suppresses FOXO1 activation. Lack of insulin activates the FOXO1-KLF15 pathway, promoting gluconeogenesis and fat breakdown. BCAA intake can prevent muscle breakdown and enhance insulin secretion.
Benefits of Ketone Bodies
The ketone body β-hydroxybutyrate (BHB) activates FOXO3a, increasing antioxidant enzymes like manganese SOD and catalase, which contribute to longevity.
Conclusion
Balancing muscle mass increase and longevity involves fasting, carbohydrate restriction, and appropriate supplement intake. Consuming EPA, arginine, BCAA, BHB, and vitamin D can help prevent muscle loss while achieving longevity benefits.