Nutrition expert Simon Jurkiw dicusses the merits of whey, casein and other protein powders
If youíre trying to gain muscle, chances are you will have heard the word protein mentioned time and time again. In gyms across the country, protein intakes and protein supplements are always hot topics of conversation. After all, the word Ďproteiní comes from the Greek word protas, which means Ďof primary importance.í
Why so important? For the body to increase lean body mass (muscle), muscle protein synthesis must be greater than muscle protein breakdown resulting in a positive protein balance. Training stimulates muscle protein synthesis but also results in muscle protein breakdown. Without the ingestion of dietary protein, muscle breakdown remains greater than muscle protein synthesis, i.e. no muscle growth/catabolism. This is where the basic logic for a post workout shakes comes from Ė to increase protein synthesis resulting in a positive protein balance and muscle growth.
Despite the above, it isnít a case of the more protein the merrier. There will be a point where additional protein will be of no further benefit. Most research suggests that around 2g protein per kilogram of bodyweight would be beneficial for strength athletes. So, a 90kg strength athlete would require around 180g protein throughout the day.
Many people find it hard to ingest an adequate amount of protein exclusively from whole food sources, hence the popularity of supplemental protein. For many, this is where it can get confusing. Is a Whey Protein the right choice? Whatís best, Whey Protein Concentrate or WPI? What about a Protein Blend? Is Soya a good protein source? Below, some of the common protein sources used in sports nutrition products are explored.
Without doubt, the most popular type of protein used in sports nutrition is Whey Protein. The first point with Whey Protein is that itís a food product. Milk naturally contains around 20% Whey, with the remainder being Casein. Breast Milk contains around 60% Whey Protein.
The starting material is generally cheese curd and the whey is separated through a number of different processes, which can vary depending on manufacturer.
Whey Protein is well researched, fundamental findings include:
Speed of absorption: The absorption kinetics of Whey show that it is absorbed far quicker than other protein sources, resulting in increased levels of amino acids in the blood.
Amino Acid Profile (in particular Leucine): Whey Protein contains all Essential Amino Acids and is rich in Branched Chain Amino Acids. Recent research has focussed on the role of Leucine in stimulating maximal protein synthesis. Whey contains around 10-11% Leucine compared to around 8-9% for Casein and 7-8% for Soya.
Increases in lean body mass: Alongside resistance training, Whey Protein has consistently been shown to result in increases in lean body mass. It isnít completely clear if Whey is Ďbetterí than other protein sources, as evidence is mixed but the majority of studies that compare protein sources put Whey out in front.
Whey Protein Concentrate (WPC) and Whey Protein Isolate (WPI)
The main differences between WPC and WPI are the nutritionals.
WPI can be considered a purer form of Whey Protein with a higher protein content, less carbohydrate and less fat. If increasing protein is the aim, then either makes a good choice. If youíre really watching the calories, an argument can be made for WPI as fewer calories come from carbohydrate and fat.
There is a school of thought that the manufacturing process of WPI can damage some protein fractions, resulting in lower levels of Alpha Lactalbumin, Beta Lactalbumin and, in particular, Glycomacropeptide. This isnít entirely accurate, as WPI that has gone through Cross Flow Membrane Filtration has the same percentage of protein fractions as WPC.
It is possible to get a WPI that is even higher in protein; the highest currently available on the market is a 97% WPI with over 12% Leucine.
Often, the term instantised is used. This simply means that a small amount of Soya Lecithin has been added to aid mixability. Some Milk Proteins use Distilled Monoglycerides for the same result.
Another popular type of protein used in sports nutrition is Casein. Compared to Whey, Caseinís absorption kinetics are a lot slower. Research shows that Casein is particularly effective at reducing muscle protein breakdown, but not as effective as Whey at increasing muscle protein synthesis.
Due to its benefit on reducing muscle breakdown, Casein is often recommended pre-bed. At this time, the body will go without protein for 6-9 hours (depending how long you sleep). The slow absorption of Casein provides the muscles with a longer supply of amino acids than Whey. Recent research suggests that Casein pre-bed can aid recovery and subsequent exercise performance.
Milk Protein contains around 80% Casein and 20% Whey and is essentially a ready made protein blend. However, the ratio of Whey is arguably a little low to make any real changes in amino acid profile hence the benefits are similar to that of Casein.
Before whey came along, Egg Protein was considered the gold standard of proteins. When Biological Value (which measures protein retention) was popular, Egg had the highest score of 100 (then whey came along and biological value no longer made much sense).
Research shows that Egg Protein can maximally stimulate muscle protein synthesis and has a decent amino acid profile.
Soya has a reputation for increasing estrogen levels in men, despite numerous studies demonstrating no changes in hormone levels after Soya ingestion. However, the role of Soya Protein in menopausal women and its potential as a Selective Estrogen Receptor Modulator probably means the reputation will be around for a while.
Absorption wise, Soya sits in the middle of Whey and Casein Ė itís not absorbed rapidly nor does it take over four hours. Soya also has a different Amino Acid profile to milk proteins, with Soya being lower in BCAA and higher in Arginine.
With regard to increasing muscle, few studies have shown any evidence that Soya would be a better choice than dairy proteins. The main benefits of Soya would be for a Vegan or someone who is looking at the potential health benefits, such as lowering cholesterol levels (5% reductions in LDL Cholesterol are often seen in those with high Cholesterol levels).
Pea Protein makes a good, cost effective protein choice for Vegans. There isnít much research on Pea Protein and increasing muscle; however, there are respectable levels of BCAA, Glutamine and Arginine so an assumption can be made to its suitability.
The current trend is to consume a Whey shake before and after training and a protein blend at other times. The advantage of a protein blend is that a well formulated blend will combine protein sources to make the most of the different absorption kinetics and amino acid profiles.
Some research suggests that a blend of Whey and Casein could be more effective than just Whey post training. However, this may depend on eating habits throughout the rest of the day.
There is a wide choice of protein types in sports nutrition, the above isnít an exhaustive list. Thereís Brown Rice Protein, Beef Protein, Goats Whey and Hemp Protein to name a few.
When choosing a product, quality, taste and value for money will be important considerations. Dairy proteins have the most research and whey, in particular, has been shown to be beneficial. Milk Protein or Casein are absorbed at a much slower rate than Whey and have a role to play in between meals or pre-bed.
The main consideration is to get the training in, consume ample protein from whole food and use a shake or two to complement that.