By Christian Wernstedt
A new study fresh off the press as of March 4, 2010:
"The underappreciated role of muscle in health and disease" by Robert R Wolfe.
This is a good scientific overview in regard to the utmost importance of maintaining muscle mass for health and well being, particularly as we age.
Some points made in this study are not particularly revolutionary for paleo folks, but I think that it is an important step forward that this type of material is entering the scientific mainstream, especially since it also ties into the debate about diets. Eating according to the USDA's pyramid is almost as "catabolic" (muscle atrophying) as a diet can get, whereas a paleo diet combined with high intensity resistance training can help even skinny nerds (like myself) to put on muscle.
Here are some key points from the article according to my reading. (My own conjectures are between parentheses) :
- The availability of muscle protein (and its amino acid constituents) is the number one limiting factor in whole-body metabolism and maintenance. Essentially: When one has lost enough muscle mass, vital processes in the body cannot be maintained. For this reason, muscle mass is strongly positively correlated with survival of severe trauma and disease, and the recovery after such events.
- Muscle mass is strongly correlated with bone strength and bone mass. (The implication being that loading the bones through muscle contractions of sufficient intensity will strengthen the bones.)
- Sarcopenia, that is loss of muscle mass in old age, has a devastating effect on survival and quality of life - a quite obvious point. Further, it is much more difficult to adequately recover lost muscle mass in old age than it is to mitigate the harm through acquiring muscle mass while still young - a less obvious, but IMPORTANT point. ("Muscle is metabolic currency, so go to the gym and make a deposit today!’" as Carl Lanore, host of "Superhuman Radio", puts it succinctly.)
- Muscle, even when idle, helps to burn fat and excess calories. (Also, intense exercise has been shown to facilitate the body's adaptation to fat burning. Of course, this doesn't work well in the presence of insulin elevated by a high carbohydrate diet.)
- One's dietary intake of protein must be adequate to fuel muscle repair and growth. (Duh! But tell this to the whole grains crowd. Fortunately, the article's author goes on to criticize current dietary dogmas that recommend against foods, such as meat, that are particularly good sources of complete protein.)
In addition to these points, the article also provides a somewhat difficult discusion of how impaired metabolic function in muscle tissue is an important factor in type 2 diabetes, and it hints that such metabolic impairments may be due to lack of physical activity. A paleo-ish macro perspective on this is that, of course, physical activity of a certain intensity and frequency is what our genes "expect" in order to express the healthy bodies that our genetic blueprints were designed to deliver. I'm expecting tons of research to come out that will confirm this. (This important paper provides an intellectual framework for this revolution.)
In summary, we can add Robert R Wolfe's article to the growing pile of compelling arguments submitted by Doug McGuff, Arthur De Vany and others in regard to the importance of acquiring and maintaining muscle mass for overall health and longevity.