The Importance of Protein in Improving Muscle Mass
SEPTEMBER 23, 2016
MD Magazine Staff
Nicolaas Deutz, MD, PhD: So, the importance in treating malnutrition has been known for many decades. It started when the surgeons operated on malnourished patients and found that these patients could not survive their surgery that well. People that had were in good, nutritional condition. This type of research and treating of malnutrition has been there for many years, and it started after World War II. So, that is on the radar of a lot of surgeons. Later on, people started to acknowledge that people become older, but they also observed that they start to lose muscle mass. Then there was more research saying, “Can we stop the muscle mass loss of the older adult?” And research has first focused on getting more calories, but then people started to understand that calories doesn’t bring back muscle tissue. In the last 10 years, there have been enormous amounts of research to show that it is indeed increasing the protein intake in the older adult population, that it could help maintain muscle mass together with the exercise.
If older adults are becoming malnourished, or are at risk of becoming malnourished and/or have lost muscle mass, to my knowledge, there are no drugs available that can treat this condition. The only way that we have at the moment is actually to advise people to eat more protein in their diet. That’s a very important point. And the second point that’s always advised is to do more exercise. By combining those two, it will help to build back muscle.
There are some other interventions in nutrition. Some research showed that other components in nutrition help, but, in general, nutrition is a key part of reducing malnutrition per definition. But the exercise is also a very important component that needs to be combined there. So, physicians can devise these two things. And there has been recent research that also showed that even these two things are already important to improve the condition of people and can have an effect all the way up to mortality. Also, research in cancer patients, for instance, showed that exercise, by itself, will reduce their mortality.
Peter A. McCullough, MD: A great controversy in dietary science is, does the type of calorie really matter? Well, in terms of weight loss, the answer is probably no. Intentional weight loss, caloric restriction as a fundamental, works just fine. But in terms of maintaining a healthy body weight or maintaining, in particular, lean muscle mass or improving muscle mass, the type of calorie really matters. Now, calories are in the form of proteins, carbohydrates, and fats. And the type of calorie that we want to emphasize in maintaining and building lean muscle mass is protein. All proteins are forms of polypeptides. They are composed of amino acids. And an increase in the protein content in the diet above, what would be considered a reasonable standard is a method by which to improve lean muscle mass in adults.
If we identify sarcopenia, or a loss in lean muscle mass, that’s above and beyond that of normal aging, we will typically recommend a higher protein intake above a baseline. So, a traditional baseline in dietary science is 0.8 g/kg/day. We may increase that target to 1 or 1.2 g/kg/day of protein. And it does matter. Having that protein spread out through the course of the day allows the body multiple opportunities to absorb and intercalate amino acids into skeletal muscle, as well as process amino acids. Amino acids are a very important building block for proteins in the body, so the liver needs amino acids, the bone, as well as the other solid organs.
Nicolaas Deutz, MD, PhD: Older adults that are healthy, they usually eat more than enough calories and more than enough protein. That is absolutely not a problem in the United States and in other Western countries. But when people get sick, they start to eat less because the body moves less and the body senses this. It then says, “We don’t need so many calories,” and people start to eat less. In that situation, people also start to eat protein less because they just, overall, reduce their intake. And then a situation can come that their protein intake is too low, and they will start losing muscle mass. So, we advise usually for people that have a chance to become malnourished–because they have a certain chronic disease—that they take at least 1.2 g of protein per kilogram body weight today, which is not a small amount, by the way; it’s a substantial amount. We are usually not so afraid for the calories. Because by taking the protein, you usually take calories with it. And if you do not take enough calories, then the body will sense it and drives you to take more. Calorie intake is absolutely not the problem in the United States. It’s all about the protein intake when people are sick.
Treating older adults with malnutrition, the first streamline that usually is done is by suggesting them to improve their regular protein intake by diet. So, for instance, what usually is advised is people should start drinking more milk, maybe take some milk proteins, and eat more steak. But, for older people, eating a large steak is very hard. The mainstream, initial phase of treating malnutrition is advising more dairy product, like yogurt, milk, etc. But when that becomes too difficult for people, there is something else that’s been used, and that’s an oral nutritional supplement. This has the basis of milk and milk proteins, but has also added a lot of other components which makes it almost a replacement of the meal. And if people have a hard time eating a regular meal, then oral nutritional supplements, in addition to the small meals that people eat, are the best way to increase their intake of nutrients.