You constantly hear how great glutamine is for the immune system and for preventing muscle loss. You're bombarded with information on how branched-chain amino acids improve exercise performance and stimulate muscle growth. But guess what? Alanine may be even better than the branched-chains, and when combined with glutamine, watch out this amino-acid combination is potent stuff. As you'll soon see, alanine plays a very important role in sparing muscle protein.
You've all heard of the glucose-alanine cycle, right? If not, here's a quick biochemistry review. When you're carbdepleted (for example, when you do prolonged aerobic exercise or participate in those ill-advised starvation diets), your body borrows amino acids from muscle. Definitely not good. In fact, the body takes branched-chain amino acids from muscle, uses part of those aminos for fuel, and then takes another part to help form alanine. Alanine is then transported to the liver and converted to glucose, which is shipped back to your muscles or other tissues and used as fuel.
So it makes sense that supplementing with branched-chain aminos might help prevent muscle loss. Wouldn't it also make sense to supplement with alanine? We know, for instance, that alanine infusion helps maintain normal blood levels of glucose. Further, what if we combined alanine with glutamine, "the mother of all aminos"? As it turns out, this forms the dipeptide alanyl-glutamine, which is a pretty potent compound indeed.
In a study done at the University of Tokyo, rats infected with E. coli (to induce catabolic stress) were divided into an alanyl-glutamine group or a branched-chain amino-acid group. Researchers delivered these aminos via a continuous
pump, and both groups of rats received the exact same number of calories. Compared to the branched-chain group, the alanyl-glutamine group of rats showed a greater anabolic effect on the gastrointestinal tract. Effects on muscle weren't measured, but in a follow-up experiment, researchers found that the combination of alanine and glutamine also produces an increase in liver and skeletal muscle protein synthesis. Now, that’s intriguing! The study authors conclude that alanyl-glutamine supplementation may be useful in patients who are ill due to infection.
So should you go out and buy some free-form alanine, mix it with some free-form glutamine and abracadabra you get this powerful mix of aminos? Or do you have to ingest the two as a dipeptide? Well, since the dipeptide isn't on store shelves (yet), I'd speculate that ingesting both amino acids (as free forms) in, let's say, a 50-50 ratio, might have similar effects. Besides, alanine by itself should help preserve the branched-chain aminos in skeletal muscle. Glutamine should be utilized by the gastrointestinal tract, thus avoiding its removal from skeletal muscle.
But when this dipeptide hits the market, watch out . . . this stuff might give glutamine and the branched-chains a run for their money. I say we need to see if this potent duo of amino acids helps prevent muscle loss in bodybuilders. Is it useful in preventing some of the effects of overtraining? Perhaps it's better than glutamine alone. All questions aside, at least evidence suggests that once again, not all aminos or combinations of aminos are created equally