The Powerful 1-2 Punch Against Aging

Insulin impacts every single cell in the body. This is particularly true of the skeletal muscle, the muscle that animates and moves our body. Muscle is the main consumer of glucose. So when we eat something that is starchy, up to 80% of the glucose that hits our bloodstream is going to be pushed into our hungry muscles. 

But that’s a problem if we don’t have a lot of muscle mass. A condition known as sarcopenia is characterized by the loss of muscle mass and strength that occurs with aging. This decrease in muscle mass means there are fewer muscle cells available to take up glucose from the bloodstream. Because the body can’t clear glucose as well, insulin remains high, thus driving insulin resistance. At the same time, as the muscles are becoming insulin resistant themselves, they become less responsive to the effects of insulin and begin to shed their protein more quickly. Although insulin typically defends the muscle protein, people with insulin resistance lose some of its muscle-building benefits. Insulin resistance leads to impaired glucose uptake and amino acid transport into muscle cells, which can hinder muscle protein synthesis and growth. So as the muscle becomes insulin resistant, it becomes sarcopenic. This, in turn, drives insulin resistance, which further drives sarcopenia, and we have a vicious cycle. 

A natural question follows: what can be done?

Fortunately, a lot. 

Diet

A study published earlier this year details how ketogenic diets help improve muscle mass and function in those aging or who have sarcopenia [1]. Keto and low carb diets are diets that restrict carbohydrates so that the body can use its own stored fat for fuel, a process known as ketosis. 

Ketosis is known to enhance mitochondrial function. Because mitochondria are the powerhouse of the cell, mitochondrial function is essential to preserving muscle health. This is especially important as mitochondrial dysfunction is one of the contributing factors to sarcopenia.

Being in a state of ketosis also helps spare muscle protein breakdown, as the body doesn’t rely on muscle glycogen for energy. 

Additionally, keto diets improve insulin sensitivity [2]. As previously established, insulin sensitivity plays a crucial role in muscle protein synthesis. Increased sensitivity allows better uptake of nutrients into muscle cells, promoting muscle growth, and reducing the risk of sarcopenia. Furthermore, as keto and low carb diets prioritize protein, they offer the muscle more of exactly what it needs to repair and rebuild [3]. 

Exercise

Exercise is another key factor that can assist in healing and preventing sarcopenia [4]. Physical activity, particularly resistance training, can enhance the sensitivity of muscle cells to insulin. Regular exercise helps maintain muscle mass and strength and can counteract some of the negative effects of insulin resistance on muscle tissue.

Strength training also stimulates muscle protein synthesis [5]. This means that when you engage in resistance exercises, your body starts building and repairing muscle tissue, which can help preserve and even increase muscle mass. Resistance training helps to counteract the muscle loss associated with sarcopenia, but it also helps improve muscle strength, function, and quality.

Takeaways

Carbohydrate-restricted diets have the potential to help us preserve muscle mass and function at a cellular level as we age. When coupled with resistance training, a keto diet and exercise pack a powerful one-two punch against aging.

References

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9762714/
2. https://pubmed.ncbi.nlm.nih.gov/35469570/
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9320473/
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6165967/
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102413/