Muscle Matters: The Impact of Sarcopenia on Aging and Longevity

As we age, our bodies undergo a variety of changes, including a gradual loss of muscle mass and strength, a condition known as sarcopenia, which can start in our early thirties. Research has shown that adults can lose up to 3-5% of their muscle mass every decade after the age of 30.⁽¹⁾ This rate can increase to 8% per decade after age 60.

The positive news is that several strategies prevent sarcopenia and muscle wasting as you age. We’ll explore the causes and consequences of sarcopenia and the latest research on preventing and treating it. 

Sarcopenia Simplified

The term “sarcopenia” comes from the Greek words “sarx,” which means flesh, and “penia,” which means loss. Sarcopenia is a common problem in older adults and is associated with a range of negative health outcomes, including reduced mobility, increased risk of falls, and decreased quality of life. Sarcopenia is caused by a combination of factors, including changes in hormone levels, nutrient absorption and metabolism, and decreased physical activity. As we become less active, our muscles receive fewer signals to grow and adapt, which can lead to atrophy or muscle wasting. Additionally, as we age, our levels of anabolic hormones like testosterone and growth hormone decrease, making it more difficult for our bodies to build and maintain muscle mass.

Symptoms of sarcopenia can include:

• Reduced muscle mass and strength
• Weakness or difficulty with physical tasks
• Poor balance and coordination
• Decreased endurance and stamina
• Slower walking speed
• Increased risk of falls and fractures
• Difficulty climbing stairs
• Reduced metabolism and increased body fat
• Decline in overall physical function
• Loss of independence in daily activities

There is ongoing research into other potential causes of sarcopenia, such as mitochondrial dysfunction, oxidative stress, and alterations in the gut microbiome. Mitochondria are the energy-producing organelles within cells, and mitochondrial dysfunction can impair muscle function and contribute to the development of sarcopenia. Oxidative stress is the imbalance between the production of reactive oxygen species (ROS) and the body’s ability to detoxify them, and it has been linked to muscle wasting in older adults. Alterations in the gut microbiome, the collection of microorganisms that inhabit the gastrointestinal tract, have also been associated with sarcopenia, as the microbiome can influence nutrient absorption and inflammation.

Research is also being conducted into the mechanisms behind sarcopenia at the cellular and molecular levels. Evidence suggests that changes in the expression of certain genes, such as those involved in muscle protein synthesis and breakdown, may also play a role.⁽²⁾

Overall, sarcopenia is a complex condition with multiple underlying causes, and ongoing research is shedding light on its mechanisms and potential treatments. A comprehensive approach that addresses the various factors contributing to sarcopenia is necessary to effectively prevent and manage the condition.

So why is it so vitally important to maintain our muscle mass as we grow older? 

Boosts Metabolism: Muscle tissue is more metabolically active than fat tissue, which burns more calories at rest. As we age, our metabolism naturally slows down, making it easier to gain weight. Maintaining muscle mass can help counteract this effect and keep our metabolism firing on all cylinders.

Improves Mood and Cognitive Function: Exercise, including resistance training, has been shown to improve mood and cognitive function, including memory, attention, and executive function.⁽³⁾ By maintaining muscle mass and strength through regular exercise, we can improve our mental health and cognitive function as we age.

Improves Bone Health: Building and maintaining muscle mass also helps improve bone density, reducing the risk of osteoporosis and fractures.

Reduces the Risk of Chronic Disease: A loss of muscle mass and strength is associated with an increased risk of chronic diseases such as type 2 diabetes, heart disease, and certain cancers.⁽⁴⁾ By maintaining muscle mass and strength, we can reduce our risk of developing these conditions.

Helps Maintain Independence: Maintaining muscle mass and strength can help us preserve our ability to perform activities of daily living, such as getting up from a chair, climbing stairs, or carrying groceries. This, in turn, can help us sustain our independence and quality of life.

Stats On Sarcopenia

• Roughly 45 percent of the U.S. population is sarcopenic, and this number rises to about 60 percent in those over the age of 65 and 70 percent in those over the age of 80.
• Sarcopenia is associated with an increased risk of falls, fractures, and hospitalizations. One study found that individuals with sarcopenia had a 2.3 times higher risk of falls and a 1.9 times higher risk of hospitalization than those without sarcopenia.⁽⁵⁾
• Sarcopenia is also associated with an increased risk of mortality. One meta-analysis found that individuals with sarcopenia had a 1.4 times higher risk of mortality compared to those without sarcopenia.⁽⁶⁾
• Women are more likely to develop sarcopenia than men, in part due to hormonal changes that occur during menopause.
• Sarcopenia can lead to a condition called frailty, characterized by a loss of physical function, increased vulnerability to stressors, and an increased risk of adverse health outcomes such as falls, hospitalizations, and mortality.
• Some evidence suggests that certain medications may contribute to the development of sarcopenia, including corticosteroids, anticonvulsants, and some antidepressants.
• There is ongoing research into the use of certain supplements (such as creatine and beta-hydroxy-beta-methylbutyrate) and drugs (such as growth hormone and testosterone) for the prevention or treatment of sarcopenia. Still, more research is needed to determine their effectiveness and safety.
• Men tend to lose muscle mass and strength faster than women as they age.
• The rate of muscle loss can be influenced by changes in hormone levels, particularly a decrease in testosterone in men and women.

Simple Strategies to Keep Sarcopenia on the Sidelines

Dr. Gabrielle Lyon is a functional medicine physician and proponent of muscle-centric medicine, which involves using nutrition and exercise to optimize muscle health in order to promote longevity.⁽⁷⁾ Lyon’s approach focuses on three key factors: nutrition, resistance training, and hormonal optimization. She emphasizes the importance of consuming adequate protein to support muscle growth and repair and minimizing carbohydrates and other inflammatory foods that can impair muscle function. Lyon also recommends incorporating resistance training into a fitness routine, as this has been shown to increase muscle mass and strength while reducing the risk of chronic diseases. Dr. Lyon also believes hormonal optimization is important to muscle-centric longevity. 

Let’s take a deeper look at these key factors:

Resistance Training: Resistance training is one of the most powerful interventions to maintain muscle strength and mass as we age. This includes exercises such as weight lifting, bodyweight exercises, and resistance band workouts. Resistance training helps to stimulate muscle growth and prevent muscle breakdown, which helps to preserve muscle mass. Exercise, in general, has been shown to increase strength, aerobic capacity and muscle protein synthesis, as well as to increase muscle mitochondrial enzyme activity in both young and older people.

Balance Hormones: Hormonal imbalances can significantly impact muscle mass and function, especially as we age. In particular, women going through menopause may experience a decrease in the production of the hormone estradiol, which can lead to impaired muscle performance and contribute to sarcopenia. Consider having your hormone levels checked annually, especially if you are over the age of 40. If deficiencies in essential hormones like testosterone, DHEA, or growth hormone are identified, there are several natural strategies such as supplementation or bioidentical hormone therapy that can be utilized under the direction of your naturopathic doctor or primary health care provider. If you are interested to learn more about supporting your hormones you can read my blog HERE.

Prioritize Protein Intake: Adequate protein consumption is essential to prevent and manage sarcopenia. Protein synthesis is a complex process that involves the production of new proteins within our bodies. Proteins are made up of amino acids, which are the building blocks of muscle tissue. When we consume protein-rich foods, our bodies break down the protein into its constituent amino acids, which can then be used to build and repair muscle tissue. As we age, our bodies become less efficient at synthesizing and utilizing protein. This can be due to a number of factors, including a decrease in hormone levels, decreased physical activity, and changes in our metabolism. As a result, our bodies may not be able to synthesize enough new muscle tissue to replace the muscle tissue that is lost over time.

Experts recommend consuming at least 1.2-1.6 grams of protein per kilogram of body weight to build and preserve muscle mass.⁽⁸⁾ So if you weigh 160lbs (72kg), you would want to aim for between 86-115g of protein daily. In addition to consuming enough protein, it is also important to distribute protein intake evenly throughout the day to maximize muscle protein synthesis. Consuming protein at each meal, particularly breakfast can help maintain muscle mass.

While protein supplements can be a convenient way to increase daily intake, it is generally recommended to get protein from whole food sources as these foods also provide other essential nutrients, such as vitamins and minerals, that are crucial for overall health. It is important to note, however, that many older adults do not consume enough protein in their diets. This can be due to a variety of factors, such as changes in appetite, difficulty chewing or swallowing, or even financial constraints. For those individuals, incorporating a high-quality whey protein supplement or some of the easier-to-chew or more economical dietary sources of protein are excellent choices.

Here is a quick reference guide on protein sources so you can get an idea of how easily you can reach your daily protein requirements:

• Grilled chicken breast (4oz) – 25g
• Baked salmon fillet (3oz) – 17g
• Lean ground beef (3oz) -18g
• Roasted turkey breast (4oz) -28g
• Grilled pork tenderloin (4oz) – 24 grams of protein.
• Large egg – 6g
• Greek yogurt (6oz) -17g 
• Cottage cheese (1/2 cup) – 14 g
• Lentils (1 cup, cooked) -18g
• Grilled sirloin steak (4oz) -28g
• Whey protein powder (1 scoop/30 grams) – approximately 20-25g
• Kefir (1 cup) 8-11g, depending on the brand and type.
• Black beans (1 cup, cooked) -15g
• Hemp seeds (3 TBSP) -10g

Protein Precautions 

Some experts in the study of longevity and aging, including Dr. David Sinclair, author and professor of genetics and biology at Harvard Medical School, have expressed concerns about the potential negative effects of high protein intake on the mTOR gene. mTOR is a gene that plays a crucial role in regulating cell growth and metabolism. It is activated by various signals, including the presence of nutrients such as amino acids, which are the building blocks of protein. You can think of mTOR as a construction crew in the body responsible for building new structures, such as proteins that are important for maintaining muscle mass. However, excessive activation of mTOR can also lead to the buildup of damaged proteins and organelles, which can contribute to developing diseases such as cancer and neurodegeneration. Excessive mTOR activity has been linked to other age-related diseases, such as type 2 diabetes, Alzheimer’s, and cardiovascular disease.⁽⁹⁾ Therefore, it’s important to balance the activation of mTOR with the activation of autophagy, which is like a clean-up crew that removes damaged proteins and organelles from the body. This process of cleaning up damaged material allows for the building crew (mTOR) to work more efficiently, producing new proteins that help to maintain muscle mass.

While protein is essential for maintaining muscle mass and preventing sarcopenia, a balanced approach is best. Animal protein is generally considered the most bioavailable form of protein for the human body as it contains all of the essential amino acids needed to build and repair tissues. In addition, animal protein is generally more easily digestible and absorbed by the body compared to plant-based proteins, which can be limited in certain essential amino acids and may contain anti-nutrients that can hinder protein absorption. When opting for plant-based sources like beans and legumes, try soaking or sprouting them prior to cooking to reduce phytic acid content and increase digestibility. Additionally, pairing plant-based protein sources with whole grains or nuts and seeds can increase the amino acid profile to make a complete protein. 

In addition to strength training, hormone optimization, and adequate protein intake, there are a few supplements to consider to help stave off sarcopenia:

Vitamin D: Vitamin D deficiency is particularly prevalent amongst older individuals. Research has found that low levels of vitamin D can lead to a decrease in muscle strength and function, as well as an increase in the risk of falls and fractures among older adults.⁽¹⁰⁾ Ensure that you are getting enough vitamin D in your diet and through safe exposure to natural sunlight. Foods that are rich in vitamin D include fatty fish such as salmon, tuna, mackerel, beef liver, egg yolks, and mushrooms. Fun fact–when you expose mushrooms to UV light, they produce Vitamin D much like human skin!  

Omega-3 Fatty Acids: Omega-3 fatty acids have been shown to help preserve muscle mass and function, particularly in older adults.⁽¹¹⁾ They do this by reducing inflammation and oxidative stress, which can contribute to muscle damage and loss. Omega-3 fatty acids may also help improve muscle protein synthesis, which is the process by which the body builds new muscle tissue. In addition to their role in maintaining muscle mass, omega-3 fatty acids help to reduce inflammation throughout the body, lower triglyceride levels, and improve heart health. They may also have a positive effect on brain health and cognitive function, which are two important aspects to prioritize when considering the aging process as well.

Leucine: Leucine is an essential amino acid that plays a crucial role in muscle protein synthesis. It has been shown to stimulate muscle protein synthesis and enhance muscle recovery after exercise. Leucine supplementation, in combination with resistance training, has been found to improve muscle strength and size in older adults with sarcopenia. ⁽¹²⁾

Leucine supplements are available in various forms, including powders, capsules, and tablets. The recommended dosage varies depending on the individual weight, age, and activity level. However, most studies suggest that a daily dosage of 2-3 grams of leucine is beneficial for improving muscle protein synthesis and preventing sarcopenia.

Creatine Monohydrate: Creatine is a popular dietary supplement that has been used by athletes and bodybuilders for decades to improve exercise performance and increase muscle mass. However, recent research suggests that creatine supplementation may also be a beneficial adjunct in preventing sarcopenia. Creatine is a naturally occurring compound found in muscle tissue that is crucial to energy metabolism during high-intensity exercise. It is synthesized from amino acids in the liver and kidneys and transported to the muscles through the bloodstream. A meta-analysis of 16 studies found that creatine supplementation significantly increased muscle strength and lean body mass in older adults with no significant adverse effects. ⁽¹³⁾ In addition to its direct effects on muscle mass and strength, creatine supplementation may also improve bone health, cognitive function, and glucose metabolism. These potential benefits make creatine an attractive supplement for older adults looking to maintain their muscle mass and functional capacity.

By implementing the tips and strategies we’ve discussed, we can ensure that we remain strong, resilient, and independent as we enter our golden years. But it’s not just about preventing a condition; it’s about investing in ourselves and our future. It’s about maintaining our vitality and committing to take care of ourselves, both inside and out, to live life to the fullest. So let’s make the most of it!

References

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