Which is better for glutathione supplementation...whey protein concentrate or whey protein isolate?

You might have heard of glutathione. It is crucial to the body's management of oxidative stress. Oxidative stress affects more than 200 different diseases as well as aging. As we get older, glutathione levels decline. So its a common idea that health can be improved in the later years of life by offsetting the age-related decline of glutathione.

A number of studies of the health benefits of whey have been published in peer-reviewed medical literature. Much of the benefit of whey comes from its unique ability to increase levels of glutathione at the cellular level. You have to increase the amount of glutathione in the cells of the body because this is where glutathione does its work of eliminating harmful molecules called reactive oxidative species (ROS) and molecular fragments called free radicals.

There are different ways of increasing glutathione. Some actually work faster than whey protein. For long term use, whey protein is probably best because it supports rather than disrupts the complex glutathione metabolism of the body. Also, it is just milk protein. The long term side effects are minimal if it is mixed properly and used in moderate amounts - about 30 grams per day for an adult getting a nominal amount of exercise.

There are probably hundreds of whey protein products on the market. Some are rather expensive. Many are optimized for use by bodybuilders, not for glutathione supplementation. Which is best?

The reason why whey protein increases glutathione probably has to do with the fact that it makes the amino acid cysteine available to the cells of the body. Availability of cysteine is the main factor that limits production of glutathione. Whey protein contains cysteine in the form of cystine and gamma-glutamyl-cysteine. In this form, it has a much higher availability than if you were to injest cysteine directly. The two protein components of whey that contain cysteine in this form are immunoglobulin and bovine serum albumin.

Oftentimes, protein composition of a whey powder product is not provided the manufacturer. However, if it is, look for about 10% immunoglobulin (IMG) and 10% bovine serum albumin (BSA). This tends to be a sort of "sweet spot" where effectiveness and value are optimal.

So which is better... whey protein concentrate or whey isolate? The commonly accepted definition of an isolate is that it contains 90% protein by weight or better. Concentrate contains less than 90%. The total amount of protein is not as important as the type of protein. Whey protein isolate is often depleted of the higher molecular weight components described above (BSA and IMG) by the additional processing step. Whey protein concentrate tends to be a better choice.