Muscle Loss As We Age: Understanding Sarcopenia

How Protein Can Keep You Strong and Healthy.

The image many people have of protein foods is that they’re mostly for body builders, weight lifters and football players. The fact is, everyone needs daily dietary protein to be healthy and fit. We require it to meet our basic nutritional requirements to help build and maintain our bones, organs and glands. We use dietary protein to make health-promoting enzymes for energy, hormone balance, digestion, and immune function. And, protein is very important for brain function.

We also need to consume protein each day replace the millions of muscle cells we normally lose. Otherwise, muscle mass is reduced. By maintaining them, we not only sustain our strength and ability to be agile, we also protect our bones, and prevent injury.

At one time low muscle mass was considered a problem mostly in those over age 60, but now it’s a health issue in younger adults and even children. Why? The overfat epidemic—people are getting fatter with less muscle. Lower levels of muscle are associated carbohydrate intolerance and chronic inflammation.

Health Survey: Common signs and symptoms of chronic protein malnutrition.

Do you have any of the problems listed below?

1. Reduced muscle strength.
2. Muscle imbalance (aches and pains, chronic injuries).
3. Hormone imbalance.
4. Carbohydrate intolerance.
5. Chronic inflammation.
6. Reduced physical performance or disability.
7. Slow walking speed (less than about two steps per second).
8. Poor balance.
9. Low vitamin D (blood test below 50 nmol/L).
10. Difficulty ascending stairs or getting out of a chair.
11. Eat meat, fish or eggs less than three times a day.
12. Taking antacids or drugs to reduce stomach acid.

What is Sarcopenia

Many people complain about getting old. They slow down, have more aches and pains, and lose strength. Their balance is lost, risking falls and broken bones. I’m not only talking about 70- and 80-year olds, but even people in their 40s and 50s have these signs and symptoms. In time, the slow reduction in height, and poor posture, which may have begun years earlier, becomes evident. The problem is sarcopenia—the loss of muscle that typically accompanies the ageing process. A key cause is inadequate dietary protein intake.

Sarcopenia is common, and is a major cause of physical disability, loss of independence, and frailty.

Writing in the September 7, 2010 issue of the medical journal Clinical Interventions in Ageing (“Optimal management of sarcopenia”) researchers Louise Burton and Deepa Sumukadas from University of Dundee in Scotland write that, “Many older adults do not consume sufficient amounts of dietary protein which leads to a reduction in lean body mass and increased functional impairment.” They also explain that the loss of muscle mass is a strong predictor of mortality in later life, and that low muscle strength, the result of lost muscle, is associated with increased risk of death.

Our muscle mass peaks in our 20s and 30s, and by our 40s starts to drop. By 50 there is a steady decline in our muscles throughout the body. But it need not be the case in everyone—we control much of these changes through lifestyle.

One main reason we lose muscle is from reduced intake of protein (the other has to do with low levels of physical activity). Just eating sufficient amounts of protein foods not only can help maintain muscle mass, but prevent sarcopenia.

But the problem of low muscle mass is no longer just one of aging. Even young people, including children, are not building their bodies early in life. Preethi Srikanthan and colleagues from UCLA’s Department of Medicine write in a May 2010 issue of the medical journal PLOS, “With the ongoing obesity epidemic in the U.S. and the disturbing increases in the incidence of obesity in children and young adults, our data suggest that we can expect to see sharp increases in sarcopenia and diabetes in the coming years. In this environment, interventions aimed at increasing muscle mass in younger ages and preventing loss of muscle mass in older ages may have the potential to reduce type 2 diabetes risk.”

Because muscles do more than move our bodies, lowered muscle mass can also cause poor circulation, reduced immune function, especially in controlling free radicals, and can place us at risk for carbohydrate intolerance and diabetes, increased blood fats (cholesterol and triglycerides), hypertension, and cardiovascular disease.

As body function diminishes and ill health rises, sarcopenia can worsen to a more advanced condition called cachexia—a metabolic syndrome with chronic inflammation at its root, with even more loss of the body’s muscles. Where sarcopenia ends and cachexia begins is difficult to distinguish, but the key is preventing it by maintaining optimal protein intake and physical activity.

Coming Soon: The sarcopenia scan scam

Like the rage in bone scans in recent decades, scanning the body’s muscle mass will soon become the latest healthcare trend. It will be done not to inform you to eat better and exercise, but to sell you some special dietary supplement or “new” workout DVD specifically designed for muscle loss. New drugs will also become popular. But none of these will be better than just eating right, including protein everyday, and easy exercising, such as walking.

Two accurate methods of measuring muscle mass is magnetic resonance imaging (MRI), considered to be the most accurate, and dual energy X-ray absorptiometry (DXA) as it also measures both fat and bone mass. They are not perfect as the tests are difficult in distinguishing muscle from water retention, and muscle fat. Bioelectric Impedence Analysis is a cheaper, quicker, noninvasive method for measuring muscle, but its reliability varies with an individual’s hydration status, ethnicity, physical fitness, and age.

How Much Protein?

The answer to this question depends on you and your particular needs. Factors such as lean body mass (how much muscle you have), your level of physical activity, and what makes you feel best after a meal, can help guide you. There is a wide range of healthy protein intake. General estimates on protein needs can be made by a percent of calories in your diet, or, with a more detailed approach using a range of normal using the USDA’s guidelines as the bare minimum needs. Here are two examples:

• If using a percent of total calories, most people will fit into a range of about 20-30 percent of the diet as protein. So if you’re eating 1,600 calories a day, protein needs might average 80 to 120 grams. Here are some protein foods to obtain this amount: two eggs at breakfast, a small 4-ounce sirloin steak for lunch, 4-ounce filet of wild salmon for dinner, and a handful of almonds for a snack. But this would be for a person not very physically active. With an increase in exercise and other physical activity comes the need for more calories and more protein. A person who works out regularly may eat 2,500 calories and may need 125 grams of protein — this would include three eggs at breakfast, a salad with a 6 ounce serving of chicken for lunch, 6 ounce pork loin for dinner, and a snack or two that includes almonds and cheese.
• Another evaluation could include the USDA’s recommendations as the minimum amount of needed protein. This is based on body weight and not lean muscle mass—0.8 grams of dietary protein per kilogram (2.2 pounds) of body weight. A person weighing 150 pounds might consume 60 grams of protein per day. But this is a minimum, and more appropriate for people who are much less active than for those with a healthy level of physical activity. Working out everyday might bring protein need to over 100 grams.

Animal Protein Sources are Essential

The human intestinal track is well adapted for digesting animal-source foods, having evolved on a diet that included meat and fish (with varying amounts of vegetables, fruits and nuts). While the popular trend in recent decades has been toward the misconception that meat consumption is unhealthy, there are a variety of unique features of an animal-food diet that are vital for health and fitness. Here are some of them:

• Animal foods contain high levels of all essential amino acids.
• Vitamin B12 is an essential nutrient found only in animal foods.
• EPA, the powerful omega-3 fat that helps control inflammation, and the one preferred by the human body, is almost exclusively found in animal foods.
• Iron deficiency is a common worldwide problem and is best prevented by eating animal foods because it contains this mineral in a most bioavailable form.
• Vitamin A is found only in animal products. Vegetables and fruits contain beta carotene which is not vitamin A; its conversion in the body to vitamin A is not always efficient in humans.
• Animal products are dense protein foods with little or no carbohydrate to interfere with digestion and absorption.
• People who consume less animal protein have greater rates of bone loss than those who eat larger amounts of animal protein.
• Creatine, the best source is meat, is an important amino acid to build muscle and prevent its loss.
• The amino acid glutamine, the main energy source for optimal intestinal function, is primary found in meat, especially those minimally cooked such as rare beef.

Preventing loss of muscle mass with aging, and building and maintaining muscles in people of all ages is vital for optimal health and fitness. Eating sufficient protein everyday, along with physical activity, accomplishes this task quite easily.