By Dr. Michael Colgan

On average, high quality milk is 27 percent protein, 37 percent lactose (milk sugar), and 30 percent fat.  The remaining 6 percent is calcium, other minerals, and ash.

Thus, what is called “4 percent milk” or “whole milk” is a high fat food, because the percentage determination includes the water, and milk is mainly water.  Its label is largely a commercial fiction.  It is not a prime food, especially when trying to increase muscle or to reduce body fat.

What is called “2 percent milk” still contains more fat and more lactose than protein.  It is not a prime food either.

Skim milk has near zero fat but still contains a high amount of lactose. Skim milk powder, which some people use in cooking and as a low-fat protein source, is the worst of milk, because more than half of it is lactose.

Up to 30 percent of adults have varying degrees of allergic responses to lactose, because lactase, its digesting enzyme in the gut, declines rapidly during childhood. Humans and their pets are the only adult animals that drink milk.

Milk Proteins

There at least 14 different proteins in milk split into two groups, caseins and wheys.

Casein represents about 80 percent of milk protein. Casein has poor results in producing lean mass in athletes, and in hospital studies of muscle loss.*

Whey represents about 20 percent of milk protein. Whey has superior results to any other protein, including eggs, meats, fish, soy, nut, pea, rice, and other plant proteins, in producing lean mass in athletes, and muscle in hospital studies. Recent genomic research attributes much of the benefit of whey protein concentrate to two unique proteins, beta-lactoglobulin (60percent of whey protein), and alpha-lactalbumin (25 percent), that together regulate the activity of more than 200 human genes.

To legally call a product whey protein concentrate it can have anywhere from 29 percent to 89 percent whey protein. At the bottom end of that scale (29 to 49 percent protein), you can work out that the other 50 to 70 percent is almost all fat and lactose. You will see a lot of this cheap whey for sale in bulk stores and discount markets. Leave it on the shelf. The new shirt you buy with the money saved will not look good on a pumpkin.


Near the top end of the whey scale (70 to 89 percent protein), only 10 to 25 percent of the mix is fat and lactose. That’s where you want your whey to be.**

Whey protein concentrate is further extracted to become whey protein isolate (90 to 95 percent protein). The higher price of whey isolate, however, is money wasted.  Both high-end concentrate and isolate are fast proteins, that is, they are very rapidly absorbed compared to casein or meat or fish proteins. But, until the advent of recent molecular genetics, we could not understand why whey isolate (90 to 95 percent protein) and high end whey concentrate (70 to 89 percent protein) produced identical results in increased free amino acid pools in the body, increased muscle protein formation, and reduction of fat deposition. Now we know that, after most of the fat and lactose is removed, the structure of the proteins is more important than the last few percent of extraction in expressing the genes that build muscle and inhibit adiposity. The structure of the proteins depends on the quality of the milk.

Quality, Quality, Quality!

Half the dry weight of your body is protein, over one hundred thousand different proteins, each of which is precisely determined by gene expression. The quality of your proteins determines both the quality and the quantity of their effects on the genome. Quality of the proteins in milk depends on the nutrition of the cows and the method of protein extraction.

Nutrition of the Cows

Cows are ruminants, continuous grazers. They have a rumen, a miraculous fermentation tank in their gut designed by tens of millions of years of evolution to digest grass and humus (grass that has died and broken down to become a stable mat for the growing grass). The rumen is designed precisely to ferment grass. In order to work properly it has to stay at a good level of fermentation continuously. Unlike the human gut, which operates intermittently by acid, the rumen is acid neutral, and requires constant grazing and a constant level of fermentation to remain healthy and support high quality protein production.

Over the last 50 years, the economics of commercial farming in the US has progressively eliminated most pasture feeding. To make a living, most farmers have to keep their cows in feedlots most of the time, and feed them on cheap hay, corn, barley, soybeans and fat. These feeds are much cheaper than pasture, but require an acidic gut to digest them. The feedlot cows are also fed only intermittently.  So most dairy farming places a large intermittent and acid load on a rumen and liver that were not designed for it. Some places, notably New Zealand, still pasture feed most of their cows.***

The diet and confinement of US cows has produced most of the problems that now beset American milk production. Feedlot cows rarely go four months without infection, requiring constant dosing with antibiotics. Feedlot cows produce milk so poorly that production has to be stimulated with hormones. Feedlot cows last an average of only four years before liver and other problems from acidic food get them switched out and turned into beef.  No surprise that feedlot cows produce inferior milk.

To give you a quick perspective on how bad it has become, in March 2010, the U.S. Department of Agriculture published new access to pasture rules for the best-of-the-best, organic cows producing high-quality organic milk. The new rules state that organic cows have to be out on pasture for not less than 120 days per year, and have to receive at least 30 percent of their feed by pasturing during the grazing season. At least they recognize the  right way to raise cows. But what a minimal standard! And that’s for the-best-of-the-best, so you can imagine what’s happening to the rest of the cows (85 percent). I hope I have convinced you to buy whey protein extracted from the milk of grazed animals for your health’s sake.

Extraction of the Whey

Whey is extracted from milk by numerous methods. Most common use acids or salts, and heat. All these strategies denature the whey. Denaturing involves numerous breakdowns in the protein, but here I will mention only two of the main faults.

First, we now know from gene expression studies that undenatured whey contains many bioactive compounds including antibodies and enzymes that have multiple beneficial effects in humans. When the whey is denatured, these bioactive compounds are destroyed.

Second, undenatured whey contains numerous di-peptides (amino acid pairs) and tri-peptides (amino acid triples). These are keys that fit specific genetic locks in the body to turn on protein functions. If the whey is denatured, the keys are broken down into single amino acids and no longer work.

It’s true that the milk industry didn’t know of these problems until recent science uncovered them. But it is expensive to change your technology, and its not happening in this economy. Undenatured whey protein is extracted by cold-membrane filtration. It costs more, but it’s the only whey to go.

Dr. Michael Colgan is a world-renowned research scientist, leading expert in the inhibition of aging, and a member of the Isagenix Science Advisory Board. Dr. Colgan has provided nutrition, training and anti-aging programs to more than 11,000 athletes, including many Olympians. He is director of his eponymous Colgan Institute, a consulting, educational and research facility concerned with the effects of nutrition and exercise on athletic performance, along with prevention of chronic degenerative disease, and prevention of degeneration of the brain.

To read more articles by Dr. Colgan, click on one of the following links:

*Editor’s note: Although the majority of Isagenix IsaLean Shake protein comes from whey protein, there is some undenatured milk casein included because of studies showing it supports general satiety, sustained maintenance of blood level amino acids, and sustained maintenance of blood sugar. For more information about whey and casein studies, click here.

**Editor’s note: Isagenix only uses undenatured whey protein at 80 percent or more protein containing very low amounts of lactose.

***Editor’s note: Isagenix continues to source our dairy proteins (including whey protein) from New Zealand dairy farmers who raise their cows on pasture and don’t use routine antibiotics or hormones. However, to meet the demands of astounding Isagenix growth, we have also sought other suppliers in Australia and the U.S. who meet the same standards for dairy protein. While not “USDA certified organic” due to supplier limitations, we believe that our dairy protein quality exceeds most organic standards. As with any of our ingredients, our dairy proteins are always rigorously tested for their quality and to be sure they are safe. Rigorous testing is performed for microbial activity, pesticides, herbicides, and heavy metals. Safety and quality are our highest priority.