Milk is made of two proteins, casein and whey. Whey protein can be separated from the casein in milk or formed as a by-product of cheese making.
Whey protein is considered a complete protein and contains all 9 essential amino acids and is low in lactose content. People commonly use it as supplementation, alongside resistance exercise, to help improve muscle protein synthesis and promote the growth of lean tissue mass.
Whey protein composition
Whey protein is a mixture of the following:
- Bovine serum albumin
Whey protein types
There are three primary types of whey protein : whey protein concentrate (WPC), whey protein isolate (WPI), and whey protein hydrolysate (WPH). Let's look at each of these in turn:
- Whey protein concentrate - WPC contains low levels of fat and low levels of carbohydrates (lactose). The percentage of protein in WPC depends on how concentrated it is. Lower end concentrates tend to have 30% protein and higher end up to 90%
- Whey protein isolate - WPIs are further processed to remove all the fat and lactose. WPI is usually at least 90% protein
- Whey protein hydrolysate - WPH is considered to be the "predigested" form of whey protein as it has already undergone partial hydrolysis - a process necessary for the body to absorb protein. 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.
Possible 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.
We assess the possible health benefits of consuming whey protein below. Note that many of these potential benefits are based on single studies and more evidence is required before making definitive judgement.
Aiding weight loss
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
Promising results were published in the journal Anticancer Research for the use of whey protein concentrate (WPC) and glutathione modulation in cancer treatment.5
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
Whey protein could improve immune response in children with asthma. One study, published in the International Journal of Food Science and Nutrition, found that children with asthma who were supplemented with whey for one month had an improved cytokine response.7
Lowering blood pressure and reducing risk of cardiovascular disease
Research published in the International 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.
A study published in the journal Clinical and Investigative Medicine1 found that whey protein may help reduce weight loss among HIV-positive patients.
On the next page we look at the possible side effects of whey protein, how whey protein can help with building muscle and how whey protein is produced.