It’s inevitable. We lose muscle mass and strength as we get older. And once age-related muscle loss becomes severe, the condition is labeled sarcopenia. About 30% of people become sarcopenic as they age. Although not technically accurate, sarcopenia has also become an umbrella term to refer to the general loss of muscle with aging.
Once someone has lost a significant amount of muscle, the functions of daily living are seriously affected. In fact, adverse health consequences can result from even a modest loss of muscle.
Consequences of Loss of Muscle Mass and Strength with Aging
There is widespread recognition that both muscle mass and strength are lost with aging. However, the physiologic significance of this loss is often underappreciated. It is well recognized that you can’t run as fast or hit a golf ball as far when you get older. If this loss of muscle strength becomes severe, basic activities can be affected, and this can have significant adverse effects on quality of life as well as much broader health implications.
Recent research has made clear that a significant loss of muscle mass and/or strength increases your risk of cardiovascular events and decreases your likelihood of surviving various diseases, including cancer and chronic obstructive pulmonary disease. Low muscle mass also negatively impacts bone health and recovery from major surgery.
Muscle is at the core of each of these health problems because it's the amino acid supply line for other tissues and organs in your body. When tissues and organs need an increased supply of amino acids for various stressors—to battle infection, repair wounds, control vascular function, balance metabolic processes, etc.—the amino acids are mobilized from the muscle tissue. Muscle also plays a role in maintaining a healthy energy balance.
Age-Related Muscle Loss Begins Before You Realize It
Quite often, people don’t recognize that they've lost muscle mass and function until they're 70 years of age or older. This oversight is particularly noticeable in older adults who don’t participate in any organized recreational activities, as they don’t experience quantitative feedback on their performance.
It’s also not easy to recognize either the long- or short-term problems caused by loss of muscle mass and function. What’s the reason for this? It has to do with a phenomenon known as the “threshold effect.”
Here’s how it works: Muscle loss starts in some people as early as age 30. By age 50, almost everyone is starting to lose a significant amount of muscle. However, you may not notice this, as your body weight doesn’t change (or may even go up due to increased fat) and you can still comfortably perform your activities of daily living.
As the loss of muscle progresses, basic function and physical activity may still be maintained, often until the onset of a health setback. Muscle loss occurs even faster when there's a serious illness, injury, or surgery.
When the normal age-related rate of muscle loss is combined with the accelerated loss that occurs in response to a health crisis, physical function may be affected to the point where you suddenly notice a problem. The “threshold” has been reached.
It’s Easier to Prevent Muscle Loss than to Regain Lost Muscle
Exercise is key to maintaining muscle mass as you age. Indeed, research has demonstrated the benefits of strength training in the treatment of sarcopenia and shown that resistance exercise can increase muscle strength and help slow the progression of muscle atrophy.
How exactly does resistance exercise work? In essence, through the use of resistance bands or even one's own body weight, small tears are created in muscle fibers. These fibers then undergo repair via the fusing together of satellite cells (found on the outside of the fibers). This process results in both muscle growth and greater strength and lean body mass.
However, if a significant amount of muscle atrophy has already occurred, you’re limited in the amount of exercise you’re able to perform. In addition, since the muscle tissue has been depleted, certain metabolic changes take place that make it less receptive to the beneficial effects of essential amino acids. This is called anabolic resistance.
The metabolic basis for this muscle wasting with aging lies in the fact that, over time, we break down more muscle than we build up. In other words, the rate of muscle protein breakdown exceeds the rate of muscle protein synthesis. What’s particularly interesting is that in the post-absorptive state (between meals), the rates of muscle protein synthesis and breakdown do not change with aging.
However, when dietary protein is consumed, a diminished amount of protein synthesis occurs. Normal protein nutrition is not as effective in older adults as it is in younger people. In fact, the same amount of dietary protein results in twice the stimulation of muscle protein synthesis in young individuals as it does in older, healthy individuals. And the lower protein diets often seen in older adults only compound this problem.
This dampened response, or anabolic resistance, is the principle reason why we lose muscle as we age. The situation is even more pronounced if an older person is under some kind of physical stress. Even a case of the flu will make anabolic resistance worse, and more serious diseases like cancer take an even greater toll.
Treating Anabolic Resistance and Sarcopenia with Hormone Therapy
The hormonal changes that occur with aging also act as a risk factor for accelerated muscle loss. This is particularly true for men, as testosterone is the primary anabolic hormone in this group, and the concentration of testosterone in the blood decreases with age.
Growth hormone secretion also shuts off virtually completely in both men and women as they age. This decline in turn affects the production of insulin-like growth factor (IGF-1), which acts on immature muscle cells (muscle fibers) to increase muscle mass and plays an important role in muscle maintenance and repair (and insulin resistance, as the name suggests).
Although the debate is ongoing, some (but not all) evidence also indicates that the decrease in growth hormone plays a role in muscle loss with aging. As a result, testosterone therapy (for men) and growth hormone therapy (for both men and women) are used by some to counteract the loss of muscle mass and strength with aging. While this can be effective, hormone therapy needs to be closely monitored, as side effects are possible.
Treating Anabolic Resistance and Sarcopenia with Diet
Dietary supplementation, mostly with protein-enhanced beverages, has been marketed and used as therapy for sarcopenia in older individuals. The general idea here is to increase protein intake and help prevent the unintentional weight loss common in older adults by providing high-quality supplements like whey protein (since the typical diet is lacking in sufficient protein).
However, intact protein supplements (those containing whole proteins, with their strings of individual amino acids connected to one another, as opposed to the separated amino acids found in free-form amino acid supplements) have not proven to be consistently helpful in reversing muscle loss in older individuals.
The problem, as referred to above, is anabolic resistance. The normal action of dietary protein to stimulate muscle protein synthesis is, again, diminished in older adults. Consequently, the use of protein supplements will not result in reversal of the loss of muscle mass and function seen in older adults.
However, there are several other dietary changes you can make that have been proven to affect muscle mass and strength.
Chronic inflammation has been implicated in the loss of muscle mass and strength that characterizes sarcopenia. This is because chronic low-grade inflammation affects both the breakdown of protein and muscle protein synthesis.
When you eat foods containing refined carbohydrates, sugar, and saturated fats, they can trigger the immune system’s release of special proteins known as cytokines, which affect communication between cells. Cytokines can work to either reduce inflammation or increase it. When you consume foods like white bread, French fries, donuts, and processed meats, pro-inflammatory cytokines are released.
As the name suggests, pro-inflammatory cytokines contribute to inflammatory processes in the body. Over time, these same cytokines can play a role in creating a chronic inflammatory state, which has been implicated in diseases such as cancer, coronary artery and liver disease, diabetes, stroke, and atherosclerosis as well as degenerative conditions such as osteoarthritis and sarcopenia.
However, diets high in fruits, green leafy vegetables, nuts, and fish have been shown in multiple studies to reduce levels of inflammation in the body. And one diet that has become well known for its track record of fighting inflammation is the Mediterranean diet.
The Mediterranean diet is characterized by:
- High consumption of fruits, vegetables, olive oil, whole grains, legumes, and nuts
- Moderate consumption of red wine, fish, poultry, cheese, yogurt, and eggs
- Low consumption of red meat, processed foods, and seeds
While most of us are probably familiar with vitamin D’s role in promoting bone health, its role in preventing and treating muscle weakness and sarcopenia may be less well known.
In fact, vitamin D has been shown to decrease muscle inflammation and increase the rate of muscle protein synthesis, size and number of fast-twitch muscle fibers (involved in powerful bursts of movement), and skeletal muscle mass and function.
Omega-3 Fatty Acids
Omega-3 fatty acids are known for their ability to help counteract inflammatory processes in the body, but did you know that studies have also shown they have the ability to overcome anabolic resistance and aid in the prevention and treatment of sarcopenia?
In fact, omega-3 fatty acids have even been shown to increase the rate of muscle protein synthesis, thereby helping to repair damaged muscle tissue and build muscle mass.
Essential Amino Acids (EAAs) and Muscle Loss
In the case of the anabolic resistance and muscle loss that occur with aging, the profile of EAAs in even a high-quality protein is ineffective. That’s because the optimal profile of EAAs to maximally stimulate muscle protein synthesis in the presence of anabolic resistance differs from the profile of EAAs in any naturally occurring protein.
However, EAAs make for exceptional dietary supplements because you can precisely formulate them for optimal efficacy in specific circumstances. In fact, daily supplementation with a complete formulation of EAAs has been shown to reverse loss of muscle mass and function with aging more effectively than hormonal therapy, and there's no risk of adverse side effects, as EAAs are natural (and essential) components of the diet.
EAAs can effectively counteract the various causes of sarcopenia and help protect against age-related muscle loss—even without exercise. In addition, EAAs can amplify the beneficial effects of both resistance training and hormonal therapy, helping to increase skeletal muscle mass, improve body composition, and enhance quality of life.