Explaining Different Protein Sources

Explaining Different Protein Sources

Protein supplements have risen to be one of the top selling nutritional supplements in the world. Protein powders used to be reserved for bodybuilders and strength athletes, but like many things that these people have advocated over the years, protein supplements have now been recognised as a great way to keep healthy and supplement you diet with a very high quality, inexpensive, convenient protein source.

When looking to buy a protein supplement you may want to bear in mind that there are a diverse range of protein sources that have been shown to have different effects on the body. Examples of these differing protein sources include whey protein, milk protein, egg white powdered protein and even protein derived from soy!

This article will give an overview of how these different protein sources are made and how they originate. How the protein sources affect the body will also be explained as this can influence your choice of protein supplement depending on your goals.

Before discussing the different types of protein sources available the biological value (BV) of protein must be explained. BV measures how efficiently a protein source is digested and then used in protein synthesis. If all of the protein you digest from a particular source is made available to the body to make different proteins it is incredibly effective and receives a high BV score. However, the less protein from a particular source that can be made available for protein synthesis receives a lower score.

This isn’t the end of the matter however as, getting into more detail protein synthesis levels are not the only factor to take into consideration when taking a protein supplement. As an example whey protein isolate will be compared to micellar casein.

Whey protein isolate has a BV score of about 160 – the highest BV score of any protein source known to man at the time of writing this article! Micellar casein comes in with a score for about 90. Although whey protein isolate has a higher biological score it is digested very quickly and spikes blood plasma amino acid levels very high, very quickly but then levels drop off very quickly too.

Whereas the micellar casein has a lower BV score and therefore doesn’t increase protein synthesis as dramatically however because micellar casein digests slower it actually increases blood plasma amino acids levels for a longer period creating a greater overall net increase in nitrogen retention.

Which one is best for muscle growth or a lean body composition? Like many things in life it isn’t a simple answer and different protein sources will be more beneficial at different times of the day; the list below explains the benefits of different protein sources and the most effective times to take them.

Whey Protein
Let’s get started with the most popular source of protein currently available. Whey protein has risen to the top of the charts in terms of protein sales; it is fantastic value and attains the highest BV rating out of all protein sources. There are three main whey protein powders that are contained in protein supplements.

Whey Protein Isolate
Whey protein isolate is a very pure form of whey protein. Isolate protein supplements undergo several purification processes that filter out virtually all of the fat and carbohydrates and because of this are about 95% pure protein by weight. There are two types of whey protein isolate supplements, categorised by the way they are filtered.

One system uses ion exchange and the other uses filtration (there are many different types of filtration process including micro filtration and ultra filtration). Using a filtration process tends to preserve more bioactive fractions than using an ion-exchange process (bioactive fractions have health benefits).

Benefits
Whey protein isolate is easily digestible, contains very low amounts of lactose and also increases protein synthesis allowing for a large spike in amino acid levels.

Reasons To Choose Another Source
Some bioactive subfractions are lost and also the protein empties from the stomach quickly so amino acid levels drop quickly after ingestion.

Whey Protein Concentrate
Whey protein concentrate is slightly less filtered than whey protein isolates and is usually about 80% protein by weight. Milk is filtered to remove almost all of the unwanted fat and carbohydrates and unlike whey protein isolates still contains many of the bioactive fractions that support immune function.

Benefits
Whey protein concentrate contains more bioactive subfractions than whey protein isolates and is cheaper. Whey protein concentrate also spikes amino acid levels, so is perfect to take post workout.

Reasons To Choose Another Source
A rapid spike in amino acid levels is good post workout when a fast source of amino acids is needed but levels also drop at a fast rate after ingestion. Whey protein concentrate also contains slightly more lactose and may spark small allergic reactions in lactose intolerant individuals.

Hydrolysed Whey Protein
Hydrolysed whey protein is pre-digested in a lab in order for it to be digested at a quicker rate when it enters your body.

Benefits
As the proteins are ‘broken up’ the protein digests very quickly and easily so anyone with a lactose allergy or who may get gas from drinking protein supplements with more lactose will benefit from taking hydrolysed whey protein. Hydrolysed whey protein also causes a large spike in amino acid levels so is perfect to take post workout when a fast acting source of protein is needed.

Reasons To Choose Another Source
Some of the bioactive subfractions are lost in the purification process. Hydrolysed whey protein also clears the stomach quickly so doesn’t feed amino acids to muscle for a prolonged period.

Casein Protein
Probably the second most popular source of protein supplements, casein supplements are gaining popularity as an outright protein source and are used by themselves as a stand alone supplement and in weight gainers mixed with carbohydrates. Casein protein supplements are also derived from milk and are cheaper than whey protein as they are not filtered as extensively but have many benefits that whey protein supplements cannot boast.

Casein protein comes in two forms; calcium caseinate and micellar casein. Micellar casein is produced using a more expensive process that protects its structure more (undenatured).

Benefits
Casein protein digests much slower than whey protein. It actually gels in the stomach and causes a much lower spike in amino acid levels (therefore its BV score is lower) however because of its slow digestion it feeds muscles with a continuous slow source of amino acids of a period of around 4-7 hours. This actually results in less muscle protein breakdown over the 7 hours compared to whey.

Reasons To Choose Another Source
Casein protein supplements digest slowly so they are not a good choice post workout. At this time the body requires a fast acting protein source that feeds amino acids to muscles as fast as possible such as whey protein. Casein protein also is not as bioavailable as whey (hence a lower BV score) and therefore doesn’t increase protein synthesis as much.

Egg Protein Supplements (Egg Albumin)
Egg Albumin is just the posh name for egg whites. Egg protein supplements are a powdered, dried version of egg whites (as this is where all the protein is contained in eggs).

Benefits
Egg protein is a very good source of amino acids and its amino acid structure is very suitable for human consumption. Egg white protein has a BV score of 100. This is because, before the advent of whey protein it was thought that egg whites were the best form of protein for humans (and then whey came along and got a score of 150!).

Reasons To Choose Another Source
Whey protein is more bioavailable than egg protein so egg protein can be used as a source of slow release protein like caseinate.

Soy Protein
The outsider in terms of protein supplements soy protein is not a pure as other forms at about 70% protein by weight. Soy protein is an obvious choice for vegans and has a relatively good amount of amino acids.

Benefits
Great for people who don’t eat animal products
Reasons To Choose Another Source
Overall the other sources mentioned are just better at their specific jobs than soy protein

To Summarise
As you can see there are a few different types of protein supplement available, all with differing cost, purity and effects on the body. The main point to keep in your mind is that no matter what source your protein comes from to take the right amount daily. Weight training individuals require roughly 2g of protein per kg of bodyweight daily, best split between 4-6 servings.

As mentioned previously at different times of the day the speed at which protein digests is an issue. For example in the morning, pre and post workout a fast acting source such as whey can be taken to good effect. At other times such as before bed or between meals a casein supplement would be beneficial. Bear in mind also that many supplements use a blend of all or some of the proteins mentioned for a more far-reaching supplement that can be beneficial for muscle growth.

Whatever supplement you decide on, remember that protein can also be found in many foods including all meat and fish sources and lots of non-animal sources. It is always beneficial to attain protein from different sources to gain the benefits of the different amino acid pools that they contain.

If you are undecided on whether or not to buy a protein supplement just remember that they are cheaper per serving and more convenient than natural sources and can be used at any time of the day to increase your protein intake and give the body a break from eating chicken all the time!