Leucine. What it is and why it's important for maintaining muscle as you age.

You may have seen or heard about essential amino acids or complete proteins or even BCAAs. But what are they and why are they important?

Proteins are large molecules comprised of smaller building blocks. These building blocks are amino acids, and there are about twenty important to human physiology, but nine of them are called essential amino acids.

Why essential? Our bodies can manufacture the non-essential amino acids, but must find the essential amino acids in our diet.

Three of the essential amino acids, leucine, isoleucine and valine, are known as branched chain amino acids. They are found at much higher levels in milk, eggs, meat and fish rather than plant sources, and are involved in the repair and growth of muscle tissue.

In fact, it has been established that leucine triggers muscle protein synthesis, but only when consumed above a specific threshold and only when co-ingested with sufficient protein. The thing is, this threshold increases with age. So what’s the threshold?

Around 2.6g of leucine per meal.

This increases with age, with older men (70+) needing twice the amount of protein as younger men before reaching optimal rates of muscle protein synthesis.

So , if you want to maintain muscle mass, the message is:

look for a protein supplement with at least 2.6g leucine