Nobody wants to lose muscle, but muscle mass loss as we age is typical. And while there’s been no set rate of muscle mass loss associated with normal aging, research points to 35 percent to 40 percent muscle mass loss between the ages of 20 and 80. Some sources say that, unless we exercise muscles correctly, then we can lose five to seven pounds of muscle tissue each decade of our adult lives.
Other reports say that those changes can occur as early as the 20s, but there is agreement that the most significant changes occur after age 50. Both men and women generally lose the same percentage of muscle mass with aging, but women lose less mass overall. Unfortunately, as muscle mass is lost, there is often also an accumulation of more body fat during that time.
So, what can be done to slow muscle mass loss? Exercise and diet can help people hold on to muscle mass longer, since active people tend to lose muscle mass more slowly than sedentary people do. A focus on strength training several times a week can help. Also, getting adequate protein—healthy, complete protein—is necessary.
One of the contributors to muscle mass loss due to normal aging is not only being inactive or having a protein-poor diet, but also that the body’s ability to produce new muscle proteins appears to diminish with aging. In fact, a study featured in the American Journal of Physiology found that the ability to produce new muscle protein was reduced by 31 percent in middle age and 44 percent in older age.
But what can be done about that? Some suggest upping protein intake for older adults. Roger Fielding, Ph.D., director of the Nutrition, Exercise Physiology and Sarcopenia Laboratory at Tufts University, advises higher protein intake to maintain and build muscle mass as well as to ensure adequate intake of the essential amino acid leucine.
Fielding explains, "Leucine has a potent effect on stimulating muscle protein synthesis. If you consume protein foods that are rich in leucine, they seem to stimulate muscle protein synthesis more than other comparable protein foods."
For example, Fielding cites that a 154-pound man should get 70g to 84g of protein daily compared to the 56g recommended by the current RDA level. Likewise, a position paper by The Academy of Nutrition and Dietetics suggests an intake of about 25g to 30g of protein at each meal for older adults.
Some sources of protein-rich foods are lean meat, poultry, fish and seafood, eggs, beans, lentils, nuts and seeds. You can also meet your protein needs via supplemental, complete protein—especially one rich in leucine for proper muscle health.
Other natural physiological shifts can add to the decline in muscle health as well, including loss of nerve cells that inform the brain to move muscles, as well as hormonal changes associated with muscle loss. For men, that’s lowered testosterone levels; for women, lowered estrogen levels. Additionally, men and women alike lose growth hormone and insulin-like growth factor. Likewise, vascular changes can affect how nutrients are delivered to muscles. Then there’s the acidity of the body. The body becomes more acidic as the kidneys age, leading to an acidic environment that triggers protein breakdown.
The bottom line? Exercise those muscles, especially with strength training a few times a week, and make sure you have adequate protein in your diet. Given the other physiological shifts mentioned, it sounds like a good idea to keep your neurological, vascular and hormonal health in check, too, as well as keeping your body in a less acidic and more alkaline state.
Here’s to strong muscles for a lifetime.