Casein expert guide: variety, benefits, dosages

Casein is a calcium-rich, slowly digestible protein source that is naturally anti-catabolic. Casein is and remains a basic supplement for bodybuilders, athletes and fitness enthusiasts!

This guide will teach you the following:

• What casein protein powder is and how it differs from other protein sources like whey protein.
• What the primary benefits of casein supplementation are for those looking to build muscle and/or burn fat.
• The recommended amount of casein and the optimal times to take it

What is casein protein?

If you've read our whey protein guide, then you'll know that whey protein is the term used to describe a group of milk proteins isolated from whey, which is a by-product of cheese production.

Casein is the other predominant form of protein found in milk and makes up about 80% of the protein in cow's milk. Similar to whey protein, casein also contains a variety of bioactive peptides that have additional properties besides their muscle building capacity.

Casein is often misrepresented in the popular media and its nuances are often not addressed. This expert guide will clear up a lot of marketing hype and give you the information you need to know.

We will show what casein exactly is, how it is made and the different forms it comes in. We will also take a look at the most frequently asked questions regarding its use.

Is casein safe and harmless?

Based on what we know right now, which is quite a lot, casein appears to be perfectly safe and harmless for human consumption.

There is this old myth that protein supplements can damage the kidneys. However, this is simply not true. Every single study published to date has shown that high protein intake does not harm your kidneys in any way if you are a normal healthy person. Protein does not change your urine health markers!

If you suffer from kidney disease, it is of course wise to keep your protein intake moderate, but for healthy individuals, even a protein intake of 4 grams per kilogram of body weight per day seems to be fine.

Sadly, the myths about protein supplementation including casein don't stop there. For a while it was believed that casein was linked to cancer, but it turns out that this assumption has nothing to do with reality. Let's take a closer look at this topic.

Does casein cause cancer? (The Chinese study)

As a scientist, one of the worst things I find is when someone misinterprets data and causes a lot of unrest about an issue. The Chinese study has done just that.

The summary of the China study goes like this: "Animal protein caused cancer in mice and consumption of more protein was associated with cancer in humans in China."...Now unfortunately, this is not the truth.

Here's the real story of the China study...

Originally, rats that were poisoned and consumed 20% of their diet in the form of casein developed lesions as part of a study, while rats that consumed only 5% of their diet in the form of casein did not. At this point, let's ignore the fact that rats and mice did not evolve to eat large amounts of casein, fish or the like, and only examine the actual scientific study.

If we look at the actual data from the animal studies (we've read through all these studies and there are a lot of them), they basically show that both fish protein, casein protein, and plant protein have the ability to alter the progression of tumor development in mice exposed to tumor compounds (1-6).

This is kind of like saying "If you go into a nuclear reactor, you'll probably develop tumors and eating a ton of protein will make it worse." To me, the studies done with mice mean nothing to us as humans who don't go into toxic chemical factories or nuclear reactors on a daily basis.

The whole toxin story is a big part of the studies and so you can't begin to say that casein caused cancer in these studies.

If I tried to publish a scientific paper like that, the people who proofread it would laugh at me and then reject my paper.

But it gets worse when you look at the actual data in the human studies, which are completely inconsistent. Casein/animal protein consumption has been associated with a small increase in risk for some types of cancer in SOME provinces of China.

However, it was also associated with a much lower risk of some types of cancer in other provinces of China. Basically, the scientists found no good correlational data and with absolute certainty no causal data.

I think it's safe to say that casein is safe and harmless for human consumption.

Do I suffer from a casein allergy

I do not know. You may or may not suffer from such an allergy. A casein allergy is nothing unusual as it is basically an allergy to milk proteins. If you feel that you are experiencing symptoms of an allergic reaction after consuming milk or casein, then you should consult your doctor.

Some people who suffer from such allergies can even consume hydrolyzed casein without side effects, as it has been broken down into smaller peptides that do not cause the same immunological reactions as the whole proteins.

The benefits of casein protein

Can casein protein be used for weight loss?

Consuming dietary protein in the form of protein supplements is a common aid to a weight loss program. One of the benefits of increasing protein intake is based on protein's ability to keep you fuller for longer on carbohydrates. For many people, a high protein meal can keep you feeling full for much longer than a high carbohydrate meal.

Both whey protein and casein supplements have been studied as weight loss aids. If we look at the research from a weight loss perspective, casein probably has a slight edge over whey protein, albeit indirectly. One potential advantage of casein compared to whey protein is its better satiating effect.

As it is digested more slowly, it often results in longer satiety after a meal. This could help to reduce overall calorie intake and may promote weight loss more than whey protein.

An overview of the benefits of casein

1. Using casein is an excellent way to help you meet your daily protein needs.
2. Casein provides a complete profile of amino acids.
3. Casein can help maintain existing muscle mass during a diet.
4. Casein is an excellent source of protein to promote satiety.
5. The use of casein in baked goods can improve protein content and enhance texture.

How is casein made?

With whey protein, whey is extracted from milk through a filtering process. This results in a liquid whey protein product. The remaining solid part (also known as the insoluble part) is the casein protein.

In the production of casein, whole milk is usually mixed with a chemical - typically chymosin - which causes the milk to curdle and turns the casein into a solid mass.

The casein then passes through a series of microfilters that purify it and concentrate the micellar segments of casein. Micelles are nothing more than arrangements of molecules with the water-soluble (hydrophilic) part of the molecule facing outwards and the non-water-soluble (hydrophobic) part of the molecules facing inwards. This gives the micelles unique digestive properties.

Foods that are rich in casein

You can take casein in the form of protein supplements, but you can also consume substantial amounts of casein through natural foods. The casein content is highest in dairy products such as milk, cheese, quark and yogurt. Casein is also found in some fish such as tuna, albeit in much smaller quantities than in dairy products.

Casein content in milk

Milk is one of the best sources of casein, as around 80% of milk protein is in the form of casein. If you drink 300 ml of milk, which contains about 12 grams of protein, you will get about 9.6 grams of casein. That's quite a lot!

What are casein hydrolysates and what is micellar casein

Micellar casein

Micellar casein is the latest supplement form of casein in which the molecular structure of casein remains intact. This is important as it is then digested in a sequence of enzymatic and non-enzymatic processes in the body, slowing digestion and absorption into the body.

Hydrolyzed casein

Hydrolyzed casein is nothing more than micellar casein that has been broken down into smaller peptides by hydrolyzing the bonds. This is the same process that takes place when whey protein is broken down into smaller peptides using enzymes or acids. If you decide to use hydrolyzed casein for whatever reason, then you should definitely opt for the enzymatically broken down version as the acid will make the end product extremely bitter.

Typically, hydrolyzed casein will be significantly more expensive than micellar casein due to the processing and additional steps involved in its production. Furthermore, hydrolyzed casein doesn't seem to have any magical properties that you won't find in hydrolyzed whey protein. The magic of casein is in the micellar form, which is why I think that if you want something hydrolyzed, you're better off with hydrolyzed whey protein.

What about protein quality?

For the average person, it is very difficult to do the necessary testing to find out what quality a particular casein product is. Most casein products from reputable supplement manufacturers that have a good reputation have a very high quality protein content.

And as with any other food, there can be some dangers with casein if it is poorly processed. However, the potential dangers are so minimal and insignificant that they are more than outweighed by the potential benefits for most people.

How should I consume my casein protein?

Eat it straight from the spoon. No, just kidding, of course. There is no specific way to take casein. It can be enjoyed on its own, in a smoothie, in a bowl of oatmeal or mixed with ice cream or pudding.

Casein should be used as a supplemental protein source and not as the primary protein source of the diet, as it typically does not have the same nutrient density as whole animal proteins when it comes to vitamins and minerals.

When should you consume casein?

Casein can be consumed at any time of the day with any meal. It is slower to digest and provides longer-lasting satiety than whey protein, making it more effective than whey protein as a snack or at other times when you know you won't have a full meal for an extended period of time (e.g. when traveling).

There are also reasons to consume casein a few hours before training to ensure adequate amino acid intake during training. However, there is no study showing that casein is better than whey protein in this regard, although casein may be slightly more effective than whey protein if you consume it a few hours before training.

Casein before bed?

One of the biggest marketing claims about casein is that it is the ultimate protein to consume before bed due to its slow digestion rate. The theory goes like this: eating casein before bed ensures a slow and steady supply of amino acids throughout the night.

If you look at the scientific research, you'll notice a common thread. If you are trying to build muscle, then consuming protein before bed is likely to help you recover better and achieve a higher rate of protein synthesis. If you compare casein and whey protein, casein seems to have a slight advantage, although this advantage doesn't seem to be huge, at least in studies conducted over a short period of time.

So if you're trying to optimize your supplementation as much as possible to get the most out of your training, diet and supplementation, then using casein late at night could have some added benefits.

It's also much better than whey protein for things like cup cakes, protein cookies, protein brownies and other types of protein desserts due to its ability to act as a thickening agent.

Whey protein vs. casein

Whey protein vs. casein
Can stimulate protein synthesis	Can stimulate protein synthesis
Is quickly digestible	Is slowly digestible
Very suitable for use after training: Studies have shown that whey protein is more efficient than casein when it comes to stimulating protein synthesis post-workout	Is very suitable for use a few hours before training and before going to bed, as well as between meals, due to its slowly digestible compounds and its ability to induce long-lasting satiety.
Very suitable for various recipes to increase the protein content of a meal.	Very suitable for different recipes to increase the protein content of a meal and to act as a thickener.
Conclusion: Both whey protein and casein can be added to your supplement program to achieve round-the-clock protein synthesis and help you meet your daily protein needs. They can even be used together to simultaneously reap the benefits of fast-digesting whey protein and slow-digesting casein.

What are the differences between whey protein and casein?

People often make big claims about the differences between whey protein and casein. There are probably over 1000 articles on the internet about this topic. However, you should not fall into the misconception that you should only use whey protein or only casein. An intelligent supplement program can contain both of these types of protein. I would like to take a look at some data to show why this is the case.

A study conducted with 23 subjects showed that whey protein and casein had similar effects on muscle anabolism after exercise (7). Another study showed that whey protein hydrolysate was more efficient at stimulating muscle protein synthesis after exercise than casein (8).

The results of this study were replicated with an older group of subjects and again whey protein outperformed casein in terms of markers of muscle protein build-up.

In a study using labeled isotopes, the scientists were able to show that both whey protein and casein led to similar increases in protein synthesis rates (9).

However, as mentioned above, one of the potential advantages of casein over whey protein is that casein has a better satiating effect. As it is digested more slowly, its consumption is more likely to result in longer-lasting satiety. This could help to reduce overall calorie intake and provide greater weight loss benefits than consuming whey protein (this is speculation on my part).

Additionally, casein consumption before bedtime has been shown to promote recovery (10).

Another non-scientific aspect of casein is that when used in the preparation of foods (e.g. baked goods), it can act as a thickening agent and give baked goods and smoothies a firmer or thicker texture.

Both whey protein and casein therefore have their advantages. If you need a fast-digesting protein, then you should choose whey protein. If you are looking for a protein for the last meal before going to bed or if you have long breaks between meals, then you should opt for casein.

Should I mix whey protein and casein?

This is a brilliant idea...and something I hadn't given much thought to before. Mixing whey protein and casein could be a great way to achieve a fast amino acid intake and also benefit from the long-lasting amino acid intake of the slow-digesting casein.

Something to watch out for is which flavors you combine. (Tip: If you combine chocolate flavor with peanut butter flavor, you will experience a true taste explosion).

Casein FAQ

Does whey protein contain casein?

Whey protein should not contain casein as it is separated from casein during the manufacturing process. It is possible that some casein may be found in whey protein if the manufacturing process was not done correctly, but even in this scenario the amount of casein present would be very small and would not make a significant difference to muscle growth and long term results.

Does casein work?

This is a trick question, but yes, casein works and it works quite well for many different goals. It can be used to meet your daily protein needs. It can be used to increase protein synthesis at night. It has been shown to produce comparable results to whey protein in various studies when it comes to building lean muscle mass.

Another interesting aspect of casein is its ability to act as a thickening agent in food. You can make a kind of protein pudding with casein and use it as a thickening agent in the preparation of baked goods.

Is casein safe for teenagers?

Based on the current state of science (and there is a huge amount of research that has investigated the use of casein in humans), there is no evidence to suggest that casein could be harmful to teenagers. In fact, casein could be beneficial for teenagers as it contains a lot of components that will support growth.

Can casein help you fall asleep?

To my knowledge, there is no useful scientific research to support the idea that casein per se can help you fall asleep. However, it is theoretically possible that protein consumption could help some people fall asleep if the type of protein in question is high in tryptophan, but this is more or less pure speculation.

However, food often increases the activity of the parasympathetic nervous system while reducing the activity of the sympathetic nervous system. This could help with sleep, although this is more the result of food intake in general than casein consumption.

Can I use casein supplements if I suffer from an allergy to milk?

Allergies of this type are primarily an immune reaction to certain proteins. Thus, most people who suffer from a milk allergy are allergic to specific proteins contained in milk. Casein may contain specific proteins that can cause allergic reactions, so it is wise to consult a doctor before using casein.

In general, people who suffer from an allergy to milk are often allergic to casein supplements. If this is the case, then you are probably better off with a plant-based protein that contains a full spectrum of essential amino acids.

Can I use a casein supplement if I am lactose intolerant?

Different people react differently to casein supplements. Casein supplements are often lactose-free or contain only small amounts of lactose. This means that it is unlikely that a lactose-free casein product will cause digestive discomfort after ingestion.

However, if you try a casein product and find that you are sensitive to it, a plant-based product with a full spectrum of essential amino acids would be a viable alternative.

Can women use casein supplements? Is there a specific casein product for women?

There is no scientific evidence or any theoretical reason to suggest that women should not use casein protein. In general, women weigh less than men and therefore have lower protein requirements, but this does not mean that they should not use casein supplements.

Do rice, soy or almonds contain casein protein?

Casein is an animal, milk-based protein. Plant-based proteins do not contain milk-based products, which is why they do not contain casein protein.

How much protein should I aim for per day?

Individual protein needs and target intakes can vary greatly and are often dictated by your goals - there is no one recommendation that applies to everyone, but there are guidelines we can follow. Based on the latest scientific data, daily protein intake should be at least 1.5 grams of protein per kilogram of body weight to optimize lean muscle mass gain.

This figure can rise to 4.5 grams per day. A good range for the vast majority of people is somewhere between 1.5 and 2.5 grams of protein per kilogram of body weight.

Individuals who do more endurance sports (running, cycling, swimming, etc.) can aim for the lower end of the range. Individuals who are primarily focused on building muscle can lean towards the higher end of the spectrum.

I am a vegetarian. Can I use casein supplements?

Casein is made from animal by-products and does not contain animal meat. If you are a lactovegetarian, then you can consume casein. However, if you are a vegan who has chosen not to consume any animal products, then casein is not right for you.

Can I just drink milk instead of buying a casein supplement?

As mentioned above, milk is a rich source of casein and you can indeed get a lot of casein just by drinking milk. However, casein supplements can be more versatile and can also be easier to transport than milk.

Can casein be useful for runners or other endurance athletes?

Of course, casein can be useful for endurance athletes as it can help them meet their protein needs and is an excellent source of protein on the go. When you combine it with whey protein, you get an excellent meal replacement option when you need a high protein meal in a hurry.

References

1. Inhibition of hepatocellular carcinoma development in hepatitis B virus transfected mice by low dietary casein.
2. The sustained development of preneoplastic lesions depends on high protein intake.
3. High protein intake promotes the growth of hepatic preneoplastic foci in Fischer #344 rats: evidence that early remodeled foci retain the potential for future growth.
4. Dietary protein level and aflatoxin B1-induced preneoplastic hepatic lesions in the rat.
5. Effect of dietary intake of fish oil and fish protein on the development of L-azaserine-induced preneoplastic lesions in the rat pancreas.
6. Effect of high and low dietary protein on the dosing and postdosing periods of aflatoxin B1-induced hepatic preneoplastic lesion development in the rat.
7. Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men
8. Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men
9. Whey and casein labeled with l-[1-13C]leucine and muscle protein synthesis: effect of resistance exercise and protein ingestion
10. Physical Activity Performed in the Evening Increases the Overnight Muscle Protein Synthetic Response to Presleep Protein Ingestion in Older Men.

Source: https://www.muscleandstrength.com/expert-guides/casein-protein