What Is Whey Protein?

What is whey protein and what role should concentrates, isolates and hydrolyzed powders play in your decision when you buy one? Actually it’s rather easy: pick the whey protein powder you like best.

Casein And Whey Protein

To get us into the groove, a quick rundown of the differences between casein and whey, taken from the article on protein you can find here:

• Casein is the major protein contained in milk, while whey only appears in small amounts. When milk is drained to make cheese, the whey is a by-product that can then be used for other purposes.
• The human body absorbs casein with a rate of 6-8 g per hour, whey with a rate of 8-10 g, which is why some workout aficionados call them “slow” and “fast” proteins. If the faster absorption rate is better depends on circumstances – casein may be slower, but on the other hand will then be available to your body longer. In studies where a better effect of whey protein on muscle growth compared to casein was noted, the effect much depended on proper timing.
• Whey protein has a higher “biological value”. The BV indicates how much of the absorbed protein the body can use for its own purposes – in working out that is of course the process of building muscle mass. The BV of whey protein is 92 and for casein it’s 76, but these numbers are calculated under strict laboratory condition that might not be reached in real life.
• Although often claimed, pure whey protein powders do not necessarily contain more of the branched-chain amino acids (“BCAAs”) valine, leucine and iso-leucine than powders based on casein.

Concentrated, Isolated, Hydrolyzed?

Ok, you got the timing down, you think you will benefit from whey’s biological value and therefore  want to go for a whey protein powder.But as soon as you come to that decision, you are assaulted with the next one: Do you want a whey concentrate? Whey isolates? And what in the world is “hydrolyzed” whey protein?

• Concentrates are the most basic form of whey powder out there. Because the filtering techniques were not as good as they are today, first generation whey concentrate powders only had about 40% whey protein, the rest were lactose and fat. Today, however, they reach around 80% and the bad name they still have is not really warranted anymore.
• Isolates are the purest form of whey protein available, with around 90% of the powder being actual whey, with almost no fat and lactose left.
• Hydrolyzed whey proteins during production are broken down into larger pieces called “peptides”. Basically, a part of the breakdown process that normally your body has to do was already provided, theoretically letting your body digest the protein faster.

Which One To Pick?

Now, which one should you choose? Although many manufacturers will claim that their special process produces better whey than that other guy’s, the evidence for this is slim. Or better, non-existent. Has anyone ever measured if a whey concentrate produces worse results than a whey isolate? Not that I know of.

In my opinion, look at the tub, check if it truly is a pure whey powder and then pick the one you like best. The differences between whey protein powders are so small that deciding on taste is as good or maybe even better than comparing the claims made about different powders.

Picture courtesy of Kurt Thomas Hunt.