Supplements of essential amino acids may reduce muscle loss in knee replacements

Taking essential amino acids before and after knee-replacement surgery could encourage a quick recovery with less muscle loss, says a small study published in the Journal of Clinical Investigation.

A total of 16 people were given 20g of essential amino acids twice a day for a week before and for two weeks after knee-replacement surgery. They were compared to 12 people who also had surgery but were given 40g a day of a non-essential amino acid supplement. The placebo group lost 18.4% of quadriceps muscle mass in their operated leg six weeks after surgery. But those getting the supplement of eight essential amino acids averaged a 6.2% loss.

“We’ve learned that the essential amino acids were able to mitigate the amount of muscle loss,” says Prof Hans Dreyer, who led the work. “The functional measures that we looked at — getting up out of a chair, going up a flight of stairs and going back down the stairs — were all back to baseline in the treatment group, whereas in the placebo group those times on all of the functional measures were much longer. That suggests that this is a means at which we can accelerate functional recovery.”

The essential amino acid supplement contained a mix of histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine and valine. Essential amino acids, which are not naturally produced by the body and must come from food sources, help the body in many ways, including tissue repair.

The study is extremely small so no firm conclusions can be made.

The group now wants to look at how a longer duration of supplementation affects patients at six months and a year after surgery, but needs to secure funding first.

To read the original research visit http://www.jci.org/articles/31767.