Everything You Wanted To Know About Milk Protein Isolate

According to the DIAA (digestible indispensable amino acid score), milk protein is a higher quality protein than whey protein. But does that necessarily mean it is better to increase lean muscle? This article will answer that question.

When it comes to building muscle mass, an increase in dietary protein intake can accelerate how fast one builds Muscle. Dietary protein comes in the form of foods such as beef, dairy, chicken, fish, eggs, and various vegetable sources. These multiple types of protein possess different qualities to how well they bring the body into a positive nitrogen state. The quality is scientifically measured. Milk protein ranks as one of the highest quality proteins to increase the positive nitrogen levels in the human body. Whey protein ranks below milk protein as in terms of quality. However, whey protein powder is much more popular than milk protein powder amongst sports nutrition consumers. This article will discuss whether milk protein isolate is better than whey protein powder in terms of building lean muscle mass. 

milk protein isolate
Should you use whey protein or milk protein isolate?

What Is Milk Protein Isolate?

Milk protein isolate is a protein powder that comes from dairy cows. It has an off white appearance. When consumed as a powdered drink, it is chalky and has a robust milky mouthfeel and taste. Most people that drink milk protein powder without flavor added to it would be displeased.

Typically a dairy manufacturer will isolate the liquid milk using filtration methods to remove nonprotein components, which results in a liquid that is 90% protein. The manufacturer will then dry the powder using a spray drying method. The result is a protein powder; that is lactose-free and high in protein. Milk protein isolate is not typically instantized like whey protein powder is. Therefore it is free of soy lecithin and sunflower lecithin, which both contain phytosterols. Some nutrition experts feel that this is one advantage milk protein isolate has over whey protein powders

Milk protein isolate consists of whey protein and casein proteins. The ratio is approximately 80% casein and 20% whey. Milk protein isolate is high in BCAA’s, which makes it an excellent protein for sports nutrition and bodybuilding.  

Milk protein isolate is a protein powder that is 90 percent protein or higher. For every 100 grams of milk protein isolate powder, 90 grams of it is actual protein. No protein powder is 100% protein. Meaning you cannot have 100 grams of powder and 100 grams of protein. For example, on the supplement facts panel or the nutrition facts panel, it cannot read: Serving size 25 grams, protein 25 grams. Milk protein isolate is 90% protein. Therefore it would read 25 grams serving size and 22.5 grams of protein. If the protein p[owder is labeled a dietary supplement than it would read: milk protein isolate 25 grams, protein 22.5 grams. This confuses many people reading the label, but milk protein isolate is an ingredient.

Keep in mind that one can find milk protein isolate (MPI) and milk protein concentrate sold as sports nutrition powders. A milk protein concentrate (MPC) will be 80% protein or lower and contain significantly more lactose than milk protein isolate. One should choose milk isolate or concentrate for this reason, as well as it contains about 10% more protein per serving. Milk protein concentrate is less expensive than milk isolate. Therefore some manufacturers will lean towards using a milk protein concentrate to increase their profit margins. Remember, the higher quality powder will be the isolate, not the concentrate. Also, the manufacturers will try to say that milk isolate is subjected to more processing; therefore, it is lower quality. This is entirely false and has never been proven scientifically. Again it is them, just trying to justify using a milk protein concentrate instead of an isolate. 

Scientifically Measuring Protein Quality

Whey protein powder was invented in the early 1990s. Whey protein is a cheese by-product. Cheese manufacturers struggled to get rid of the liquid whey that resulted from manufacturing cheese. But then it was discovered that whey protein had an excellent amino acid profile, exceptionally high in BCAA’s, which are the building blocks of Muscle. The liquid whey was filtered to concentrate and isolate the protein and then dried into a powder. The powder then was flavored into milkshake type drinks. Whey protein has a huge advantage over milk protein powder, and egg white protein powder in that is was very easy to flavor into chocolate, strawberry, and vanilla milk shake type beverage. Finally, this new whey protein powder needed something to convince athletes and bodybuilders to use it in place of their milk and egg protein powder. Therefore to accomplish this, whey protein distributors promoted that whey protein powder was scientifically a higher quality protein over milk and egg. The scientific testing method is called biological value. The biological value test methodology, in layman’s terms, measures the amount of protein from certain foods that can be utilized in protein synthesis. The whey protein manufacturers would promote that whey protein had a biological value (BV) that topped milk and egg protein. Here is a typical chart that whey protein distributors would market to their potential customers.

biological value of protein
Ye Olde Biological Value Chart..outdated and obsolete.

Because of this marketing scheme, and the taste factor, whey protein powder skyrocketed in sales over milk and egg protein powders. Whey protein powder soon became the number one selling protein powder. Interestingly other protein manufacturers took advantage of the biological value testing methodology. One of the protein sources was soy protein isolate. Soy protein isolate manufacturers started marketing that soy protein was just as good as whey because soy’s biological value scored just below whey. Because of this, soy protein isolate became popular, but not too long after, soy protein was discovered to raise estrogen potentially, and then soy protein powder usage became taboo to bodybuilders.  

PDCAA Replaced Biological Value

A few years after this, around the year 2000, a new methodology was introduced, called PDCAA, or Protein Digestibility–Corrected Amino Acid Score. This methodology, in a nutshell, tested the amino acids in the small intestine instead of in the fecal matter that the biological value used. The PDCAA was now the accepted method to determine protein quality. The chart below shows the scores are various protein foods.  

PDCAA chart

Whey Protein distributors and supplement companies were not so quick to use this new protein quality method in their marketing because it ranks several other protein sources just as high as whey protein

DIAA Is Introduced, & Is The Most Up To Date

Then in 2013, the DIAA was introduced replacing the PDCAA. DIAA stand for The Food and Agriculture Association stated that the DIAA was a more accurate method than the PDCAA. And to this day, it remains the methodology to judge protein quality.

Interestingly enough now, milk protein powder is ranked #1 on the DIAA chart.

Let The Debate Begin

Because milk protein powder is at the top of the list for protein quality, does that mean one should abandon their whey protein, casein, and egg white protein powders? In my opinion, no. The study below shows that whey protein works just as well as milk protein at increasing muscle protein synthesis.

milk protein isolate

My recommendation and this has been my recommendation for the last 20 years, is to combine protein sources and use a protein blend. There are several reasons that I recommend combining protein sources. The first reason is the different rates of absorption. Most protein powders that come from various sources are digested at different speeds. Hydrolyzed proteins are digested the fastest (however it depends on the molecular weight average)

Then whey protein, then milk protein, then egg, beef, and casein. Vegetable proteins (not hydrolyzed) are digested at medium speeds, such as rice, pea, and lentil.

The benefit to different rates of absorption is that you are getting amino acids into the bloodstream for a sustained period instead of for a short period. This means that one will be in a positive nitrogen state for more time than a negative one. This, in turn, creates more of an opportunity to increase muscle growth. Remember, the human body continually goes back and forth between positive and negative nitrogen balance. Building Muscle requires a positive nitrogen balance. Muscle wasting is when the body is in a negative nitrogen state. Keeping the body fed with amino acids throughout the day creates this effect.

An abstract published in 2013 proved that a protein blend consisting of whey protein, soy protein, and casein protein powders could increase muscle protein synthesis and were acceptable to use post-training.

Milk Protein Isolate To Improve Lower Quality Proteins

One benefit of milk protein isolate is that if one combines it with a lower quality protein like pea protein isolate or rice protein concentrate, it will improve the overall quality. Therefore unless you are a vegan and want to consume pea and rice, merely adding milk protein isolate will increase post-workout recovery. One exception is hydrolyzed collagen protein powder. Recently there has been a trend in the supplement industry to consume hydrolyzed collagen as a sports nutrition recovery supplement. Unfortunately, this is a scam by the supplement industry. Hydrolyzed collagen is an extremely low-quality protein source. The DIAA of hydrolyzed collagen protein is ZERO. It is zero because it is an incomplete protein. Incomplete proteins cannot be utilized by the human body. In addition, they can lower the quality when combining with other protein sources. If one combines milk protein isolate with hydrolyzed collagen, in my opinion, I think the overall quality will be compromised. Therefore avoid all use of hydrolyzed collagen.   

milk protein isolate
Using high-quality protein, like milk protein powder supplement will give you the best chance to increase muscle mass.

You May Just Need More Protein

In the research study by Hannah M BaileyHans H Stein that was published in October 2019, they stated this….

For example, peas may have a high quantity of protein, but with a DIAAS value of approximately 64, it has a low quality score. In contrast, milk has both a high quantity of protein and high quality of amino acids with a DIAAS of 122. As a consequence, an individual would have to consume more than twice as much pea protein compared with milk protein to meet the human amino acid requirements. 

The Top Brands Selling Milk Protein Powder.

I can only recommend two brands of protein powders that sell milk protein isolate. I searched the internet and found hardly any companies offering 100% milk protein isolate or concentrate.  

The first, and really the ONLY choice is Muscle Shake. It contains milk protein isolate from the Netherlands. It is the only brand that I have found who’s protein comes from grass-fed cows. Not only that but the entire product is in its native state. It contains whey protein isolate, and casein, both in native forms.

milk protein isolate
5 lbs of Muscle Shake

Next is Agropours Bold Protein

Coming in last is Syntha 6, which claims to contain milk protein, but it contains a ton of garbage for flavoring. This product would appeal to the mass market and people that care more about taste than quality.  

How To Use Milk Protein Isolate Protein Powder

Milk protein isolate can be used by itself, but I do not recommend that. Like I mentioned previously in this article, it is always best to combine protein sources. That is what makes Muscle Shake one of the best protein powders in the world. It combines milk protein isolate, whey protein, and casein. However, when my customers ask me which protein powders they should buy, I always recommend they combine Muscle Shake with a good quality hydrolyzed protein like Peptopro, Salmobolic 98, or Hydrolyzed whey protein 520. 1/4 cup of Muscle Shake and 1-2 tablespoons of a hydrolyzed protein is superior protein powder over 99% being sold today. The quality of this powder simply cannot be beaten. Keep in mind that Muscle Shake is sold without flavor, so adding fresh fruit, like a banana and almond milk, will help with the flavor. 

In conclusion, according to the DIAA, milk protein is a higher quality protein than whey. However, that does not necessarily mean that it will build muscle better. The impact that whey protein has on insulin may make it more anabolic than milk. This must be taken into consideration. To maximize the muscle-building potential of protein powders, combine high-quality proteins with carbohydrates, and consume around your workouts. Avoid low-quality proteins, like collagen, and catabolic triggering substances like caffeine. And as always, combining resistance exercise with higher protein intake equates to increase muscle protein synthesis.