Maintaining Muscle Mass: The Key to Longevity and Overall Health

As we age, maintaining muscle mass becomes increasingly important for our overall health, vitality, and longevity. Beyond physical strength, muscle is a powerful driver of many key biological processes, including metabolism, immune function, and inflammation control. Yet, many people overlook how critical muscle mass and muscle signalling are to their long-term health, particularly when it comes to proper protein intake and the regulation of muscle growth pathways like mTOR.

In this blog, we’ll explore how maintaining muscle mass is crucial for healthy ageing, why high-quality protein is essential, and how balancing the activation and inhibition of muscle-signalling pathways like mTOR can help us optimise our health.

The Importance of Muscle Signalling for Health

Muscle is far more than just a source of strength and mobility; it plays a central role in regulating many bodily processes. One of the key regulators of muscle growth and maintenance is the mTOR pathway (Mechanistic Target of Rapamycin). mTOR is a nutrient and energy sensor that acts as a central hub for several important cellular processes, including:

- Autophagy: The process by which cells clear out damaged components, promoting cellular health.

- Protein synthesis: mTOR controls the production of new proteins, which are crucial for muscle growth and repair.

- Inflammation: Regulating mTOR can help reduce chronic inflammation, which is associated with ageing and many diseases.

- Stem cell function: Proper mTOR function preserves the ability of stem cells to regenerate tissues.

- Cellular ageing and metabolism: mTOR influences how our cells age and how our body metabolises nutrients. In essence, mTOR helps regulate muscle health, metabolism, and ageing.

However, there’s a delicate balance to strike. While excessive mTOR activity is linked to accelerated ageing and cancer risk, inhibiting mTOR too much can lead to a loss of muscle mass, reduced metabolic health, and decreased physical function.

Protein Intake: The Foundation of Muscle Health

One of the most critical aspects of maintaining muscle mass is ensuring adequate protein intake, particularly as we age. Protein provides the building blocks (amino acids) that are essential for muscle repair and growth. As we age, we experience a phenomenon called anabolic resistance, which means our body becomes less efficient at using protein to build and maintain muscle. This is why older adults require more protein than younger people to maintain muscle mass.

For individuals over the age of 60, protein requirements increase to about 1.5 to 2.0 grams per kilogram of body weight per day. This is significantly higher than the general recommended daily allowance (RDA) of 0.8 grams per kilogram, which is only the minimum amount needed to prevent deficiency. Meeting this higher protein intake helps counteract anabolic resistance and maintain muscle function.

Per meal, an older adult needs about 25-40 grams of protein with 2.5 to 2.8 grams of leucine—a key amino acid for stimulating muscle protein synthesis. Animal proteins, such as meat and whey, tend to be richer in leucine and creatine, making them highly effective at promoting muscle growth. On the other hand, plant proteins are generally lower in leucine and often require supplementation with additional branched-chain amino acids (BCAAs) and creatine to reach the same anabolic effect.

Inhibition of mTOR: The Longevity Connection

While stimulating mTOR is essential for muscle growth, inhibiting mTOR at the right times has been shown to extend lifespan in various animal models. Inhibiting mTOR triggers autophagy, the body's way of cleaning up damaged cells and promoting cellular health. This process has been linked to reduced inflammation, improved metabolic function, and preservation of stem cell activity.

Ways to inhibit mTOR include:

- Intermittent fasting: Fasting for 12-16 hours overnight can temporarily inhibit mTOR, allowing your body to switch into a repair and regeneration mode.

- Phytohormesis: Compounds like urolithin A (from pomegranates), oleuropein (from olive

oil), catechins (from green tea), curcumin, and berberine can activate AMPK, another energy sensor, which helps inhibit mTOR and promotes autophagy.

- Hormesis: Exposure to mild stressors like heat (saunas), cold (cold plunges), and hypoxia (low oxygen environments or CellGym training) can also inhibit mTOR and stimulate beneficial adaptations.

Stimulating mTOR: Building Muscle and Function

After a period of mTOR inhibition, it’s essential to stimulate mTOR to promote muscle growth, repair, and strength. The key to doing this is through a combination of protein intake and strength training. Consuming 30-40 grams of high-quality protein in the morning, particularly with 2.5 grams of leucine, is an effective way to kickstart mTOR activation and support muscle protein synthesis.

Strength training is also crucial for activating mTOR. Aim for 3-4 sessions per week of resistance or strength-based exercise to maximise muscle growth. This not only helps maintain muscle mass but also improves bone density and metabolic health.

Getting the Right Balance: The Goldilocks Approach to mTOR

When it comes to mTOR, balance is key—we don’t want too much or too little activity. Think of mTOR as the Goldilocks of muscle signalling: we need periods of both inhibition and stimulation to maximise health benefits. Inhibiting mTOR through fasting or other hormetic stressors promotes cellular repair, while stimulating mTOR through protein intake and exercise helps build and maintain muscle mass. By striking this balance, we can reduce inflammation, promote longevity, and maintain functional muscle mass well into old age.

Conclusion: Protein, mTOR, and Healthy Ageing

Maintaining muscle mass is not just about staying physically strong—it’s about optimising metabolism, reducing inflammation, and promoting longevity. By understanding the role of mTOR signalling and focusing on adequate protein intake, especially high-quality sources rich in leucine and creatine, we can preserve muscle mass and enhance overall health as we age.

Whether through strategic fasting, incorporating phytonutrients like resveratrol and curcumin, or engaging in regular strength training, the right balance of mTOR inhibition and stimulation can lead to better health outcomes, improved physical function, and a longer, healthier life.

By prioritising good quality protein, regular exercise, and a thoughtful approach to mTOR regulation, we can maintain muscle mass, promote longevity, and keep ourselves functional and strong for years to come.

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