Whey protein is a liquid byproduct of cheese production that is sold as a dietary supplement in protein powders and shakes. Whey protein used to be discarded by cheese manufacturers as a waste product.
Whey protein is considered a “complete protein” and contains all 9 essential amino acids and is low in lactose content. It is fast and easy to digest. Whenever we eat a protein source, our body uses the 20 amino acids (which are the individual components of “protein”) to repair our bones, muscles, organs and virtually every body part and tissue in the human body.
When a source of protein has all 9 essential amino acids, which are amino acids your body needs to get from food, that food is said to be a complete protein. Foods like meats, dairy, eggs and rare vegetable proteins such as quinoa are complete proteins. On the other hand, most vegetables, rice and starches are not complete proteins because they are missing one or more of the essential amino acids.
Composition
Whey protein is composed of the following:
- Beta-lactoglobulin
- Alpha-lactalbumin
- Bovine serum albumin
- Immunoglobins.
There are three primary types of whey protein : whey protein concentrate (WPC), whey protein isolate (WPI), and whey protein hydrolysate (WPH):
- Whey protein concentrate – WPC is generally the cheapest of the three and has the lowest amount of protein per 100 grams of the three types. Despite having the lowest protein content, it still has a very high percentage typically ranging from 55-89%. The other 11-45% is made up of fat, lactose and contains higher amounts of various immune-enhancing peptides such as alpha-lactalbumin and immunoglobulins.
- Whey protein isolate – WPI has on average 95% of its weight coming from protein, with minimal lactose and fat. This is more expensive than concentrate and there are varying methods of filtration that can keep many of the beneficial qualities of the concentrate, although this generally costs more.
- Whey protein hydrolysate – WPH is a further degraded protein that digests very quickly in the body and has about 99% of its weight coming from protein. This is the most expensive of the three and generally the worst tasting. WPH doesn’t require as much digestion as the other two forms of whey protein. In addition, it is commonly used in medical protein supplements and infant formulas because of it’s improved digestibility and reduced allergen potential.
Health benefits of whey protein
There are many benefits associated with the consumption of whey protein, and researchers are constantly finding new possible therapeutic properties.
The possible health benefits of consuming whey protein include:
- Losing weight – according to one study, published in Nutrition & Metabolism, people who took a specialized whey fraction (Prolibra™, high in leucine, bioactive peptides and milk calcium) “lost significantly more body fat and showed a greater preservation of lean muscle compared to subjects consuming the control beverage”4
- Anti-cancer properties – Promising results were published in the journal Anticancer Research for the use of whey protein concentrate (WPC) and glutathione modulation in cancer treatment5
- Lower cholesterol – according to a study published in The British Journal of Nutrition, “there was a significant decrease in total cholesterol and LDL cholesterol at week 12 in the whey group compared with the casein (group)”6
- Asthma – whey protein could improve immune response in children with asthma. One study, published in theInternational Journal of Food Science and Nutrition, found that children with asthma who were supplemented with whey for one month had an improved cytokine response7
- Lowering blood pressure and reducing risk of cardiovascular disease – research published in theInternational Dairy Journal found that beverages that were supplemented with whey protein significantly reduced blood pressure in patients with hypertension, their risk of developing heart disease or stroke was also lower.
Specific amino acids are used by your body for specific reasons. For instance, whey protein is high in Branched-Chain Amino Acids (BCAA’s), which are 3 of the 9 essential amino acids that are of special importance for muscle repair and preservation. In both exercise and in recovery of exercise, your body will break down a small amount of amino acids for fuel (1-5%) and the specific amino acids your body uses are the BCAA’s. Although this is a small percentage overall, your body will break down muscle in order to get those BCAA’s. By providing the body with a high amount of BCAA’s, your body preserves your muscle, while the specific amino acid leucine actually stimulates protein synthesis.
This means is that leucine sends a signal to your body to increase its storage of amino acids and the way your body primarily does this is by adding muscle.
So if you’re trying to put on muscle, having enough BCAA’s is essential to both help preserve the muscle, while also helping to stimulate additional muscle growth. If you’re in a hypo-caloric state (if you’re trying to lose weight and are cutting calories), preserving muscle becomes even more important and ensuring that you have enough BCAA’s helps to keep your body from losing muscle, while simultaneously helping you to lose fat.
Another huge benefit of whey protein is that studies have indicated that glutathione production increases. Although you may have heard of Vitamin C or Vitamin E as being anti-oxidants, what your body mainly uses as an anti-oxidant to scavenge free radicals is glutathione, making it one of the most important substances in your body. Glutathione is made from three main amino acids; cysteine, glutamic acid and glycine. The rate-limiting amino acid (what limits production of glutathione) is usually the amino acid cysteine, and although the exact mechanism with whey protein intake is not known, it is theorized that the relatively high amount of cysteine in whey is what increases glutathione production.
If you look at the list of benefits from up above (assistance with cancer, HIV, decreased recovery time, etc), most of those benefits are usually attributed to the increase in glutathione production.
A study published in the journal Clinical and Investigative Medicine1 found that whey protein helps reduce weight loss among HIV-positive patients.