Protein Supplements for the Sedentary to Prevent Muscle Atrophy

Many athletes take protein supplements to preserve, repair and increase muscle mass, which is broken down by resistance training. Sedentary people, however, especially older adults, are at major risk of muscle atrophy (disintegration of muscle tissue). Some studies indicate that protein supplementation is somewhat effective in preserving muscle mass among those who are not physically active. But, regular resistance exercise, possibly in conjunction with protein supplements, is much more likely to prevent or slow muscle atrophy.

Muscle Atrophy

• The human body relies on muscles for movement and strength but, it also stores protein, which, under physical stress is broken down into amino acids (the "building blocks" of protein) to produce and use energy. Protein repairs injured muscles and works to repair muscle tissue that is stressed by weight-bearing exercise. (This type of exercise breaks down muscle tissue, but subsequently builds it in healthy people.)

  Disease and prolonged periods of inactivity causes the muscles to stop making protein, which causes them to atrophy. Although many assume that this can be prevented through protein supplements (either in the form of whey, soy or protein powders or amino acids ), results from clinical studies have been mixed.

Supplements

• Types of supplements vary, ranging from proteins, such as caseine, whey and soy, to those that contain amino acids, such as glutamine, arganine, leucine and L orthanine and creatine. Some researchers believe these supplements strengthen muscle tissue. But, others believe that it has little---if any---benefit. People with kidney disease should not protein-load because they cannot safely tolerate excess protein.

Research Findings

• Clinical studies conducted to see whether protein supplements can slow or reverse muscle atrophy have had mixed results.

  One study involved a group of people who remained bed-ridden for four weeks to trigger muscle atrophy. They then took amino acid supplements, Testing showed that the supplements reduced atrophy in the subjects' legs.

  Some clinical trials have indicated glutamine and several other protein-building amino acids helped bed-bound surgery patients restore lost muscle tissue. Other clinical trials that focused on elderly people, who tend to be at high risk for muscle atrophy were less promising, however. One study followed active and inactive older women who received protein supplements.The supplements didn't slow muscle atrophy in the inactive group. In fact, they "actually promoted thigh muscle volume loss." But the group that exercised preserved thigh muscle tissue and thigh and calf muscle strength.

Another Muscle-Building Factor

• But, adding exercise into the mix produced different findings in some studies. One example involved study of healthy older men who did resistance (weight) training and took protein supplements before and after workouts. This group didn't build any more muscle than another group that also exercised but did not take the supplements.

  A Baylor College of Medicine study supports this finding. People on bedrest while taking amino-acid supplements lost muscle mass and lower body strength. But those who did weight-bearing exercise while eating protein supplements maintained lower body strength. The study also showed that taking protein supplements shortly before and after exercise makes them more effective.

Conclusion

• At first glance, research into protein supplementation to prevent muscle atrophy appears to be inconclusive. But studies seem to show that inactive people and those who don't get enough protein in their diets are most at risk for muscle atrophy, especially seniors. Protein supplements may help somewhat in reducing muscle tissue loss, but eating daily recommended portions of protein combined with frequent resistance training sessions (even very low intensity) is more effective.