One of the most common questions I get asked is: What is the difference between whey protein concentrate and isolate, and which one is most effective for stimulating muscle protein synthesis (muscle repair and growth)?
In order to answer this question we first need to look at what proteins are. Proteins consist of several long chains of amino acids. Once consumed, digestive enzymes break down these long chains into separate amino acids (or very small chains), which are then absorbed into the bloodstream and delivered to different parts of the body. These amino acids are the building blocks of our muscles, tissues, cells and enzymes.
What is whey protein?
Milk contains two types of protein, casein (80%) and whey (20%). During cheese production, milk is coagulated and the liquid part that separates during this process is whey. Whey protein has a high content of branch-chain amino acids (BCAA’s), which are important in ‘activating’ muscle protein synthesis, and a full profile of all other essential amino acids, which as mentioned previously are the building blocks of our muscles and optimise muscle growth and recovery.
Whey Protein Concentrate & Isolate
The two most common forms of whey protein are concentrate and isolate.
- Whey Concentrate – 30-85% protein content. Contains a small amount of carbohydrate (6-10g, half of which is lactose) and fats (4-6g, a small amount of which is cholesterol).
- Whey Isolate – 90% or higher protein content. A more pure source of protein than whey concentrate, as some of the non-protein nutrients, such as carbohydrate, lactose and fat have been partially removed, “isolating” the whey protein.
Whey Protein Hydrolysate
Both whey concentrate and isolate are available as intact proteins, however, they can also be hydrolysed. If whey protein is hydrolysed, it is exposed to heat or enzymes to split several of the bonds linking the different amino acids together. This process allows whey protein to be digested into separate amino acids and absorbed into the bloodstream faster than intact whey concentrate or isolate. Although this is the case, both whey concentrate and isolate are already quickly digested, therefore the small increase in digestion rate from hydrolysing whey may not compensate for the additional cost.
- Whey protein in any form is rapidly digested and has a full profile of amino acids, which is vital for stimulating muscle protein synthesis.
- Although whey hydrolysate allows for slightly quicker absorption of amino acids, this will provide minimal benefit for a considerably higher cost.
- Whey concentrate is the most cost-effective protein supplement. The small amounts of carbohydrate and fat present in whey concentrate above isolate are negligible when considering caloric intake and body composition in the long term.
- If you are lactose intolerant, using whey isolate may be more practical and could help to reduce GI (gastro-intestinal) upset, as a significant portion of the lactose has been removed.
- Recommendation: 20-30g of whey concentrate is sufficient to maximally stimulate muscle protein synthesis.
About the Author
Mark Funnell holds a BSc (Honours) degree in Sport and Exercise Science and an MSc in Sport and Exercise Nutrition from Loughborough University. He is currently working as a Performance Nutritionist for the England and Wales Cricket Board with both the England Women’s Academy and Midlands Regional Disability Cricket squads. Additionally, Mark is a graduate member of the Sport and Exercise Nutrition Register (SENr), an ISAK Level 1 Anthropometrist and a UK Anti-Doping advisor.