Casein: the Slow-Absorbing Protein for Athletes

November 18, 2022

Casein is all the rage. You have probably seen on social networks different influencers from the sports world taking this kind of protein, but what is casein, what is it for, and what are its benefits for athletes? We will cover all this and more,  in the following article.

What is casein and what is it used for?

Casein is a protein found in milk, which represents 80% of the protein value of this food and is responsible for helping the body with calcium absorption.

It is a slow absorption protein compared to whey (the other major protein found in milk) and casein requires 30-40% more time to be absorbed.

Casein has a perfect nutritional composition to stop muscle catabolism (destruction of muscle tissue), which is why it is used in different sports disciplines as a dietary supplement. 

In recent years, casein protein shakes have been on the rise in sports centers because it is a perfect substance to help the body during the night in the process of muscle recovery.

Casein intolerance

Although lactose intolerance and casein intolerance are not technically the same thing (the former is caused by the body's difficulty in digesting lactose and the latter by an abnormal response of the immune system to milk proteins: beta-lactoglobulin and casein), they are very similar.

Casein intolerance, like lactose intolerance, manifests itself through quite specific symptoms: gas, bloating, diarrhea, cramps, abdominal pain, and its medical diagnosis requires a good blood test and probably some other specific medical test. 

However, it should be said that casein intolerance as such, unlike lactose intolerance, appears in the first years of life and is very sporadic in adults.

Lactose intolerance and casein intolerance are not scientifically the same disorder.

In terms of treatment, the main recommendation is the suppression of dairy foods. 

Eliminate dairy products containing cow's protein and try to find alternatives with formulas made, for example, from soy. 

Fortunately, the market offers more and more alternatives for people with food intolerances, so if you detect this alteration, calm down. Everything has a solution.

Benefits of casein

  • Time: Casein is one of the proteins that remain in the body for longer and can provide a slow but steady flow of amino acids into the bloodstream. In addition, we all know that rest is as or more important than the training itself, so ingesting casein during the last hours of the day can be of great help in the process of muscle recovery.

  • Teeth health: Yes, although it may seem silly, it is not. According to a study, casein has properties that prevent enamel erosion. So if the sports benefits seemed little to you, you already have another weighty argument to continue taking casein. 

  • Muscle recovery: Casein arrived mainly in the fitness world for this reason. We are dealing with a protein that promotes muscle recovery and is therefore perfect for strength sports in which we subject the body to high muscle demand. In addition, casein can promote the increase of lean mass and is totally free of fat.

  • Anti-catabolic properties: Casein slows down catabolism, a process in which part of the muscle mass is destroyed. All this occurs thanks to the ability of this protein to prolong protein synthesis over time. In addition, thanks to its slow digestion, casein has a satiating effect on the body.

  • Bone health: Different studies seem to have demonstrated the improvement that casein exerts on bone health. As you can see, the benefits of casein go beyond a muscular issue, and its nutritional contribution is also advisable for elderly people who may have bone problems.

Side effects of casein

Casein is one of the most recommended supplements for those who practice physical exercise. However, this protein has several side effects that should be considered, especially for those who have any type of dairy intolerance:

  • Increased mucus: Different theories associate high mucus with the body's inability to adequately break down the protein bacteria in the milk. This can result in thick, sticky mucus that seems to permanently adhere to the sides of the lungs. This is nothing more than a nuisance and should not be considered a serious problem initially.

  • Kidney damage: Casein has many benefits, but on the other hand, it also has certain drawbacks. In this case, an excess of casein could generate kidney problems.

  • Increased cholesterol: We all know that whole milk has a significant percentage of fat, hence many people opt for semi-skimmed or skimmed milk. With this type of milk, the cholesterol level in the blood is easier to control.

How and when to take casein?

Naturally, foods such as cheese, milk, butter, and many other dairy products contain casein. In addition, even in a very small proportion, all baked or cooked products with a milk base may contain casein. Bechamel sauce, for example, contains casein, although the amount of this substance is practically negligible.    

For this reason, people allergic to casein should avoid this type of dairy product. Products or "milk" derived from coconut, almond, or soy do not contain casein.

Some nutritionists and fitness specialists recommend taking casein naturally or through supplementation because its properties promote muscle growth and recovery. 

In addition, according to experts, casein should be taken before going to bed because its absorption is much slower compared to whey protein. Whey protein is absorbed much faster and is perfect for after training. This is the main reason why in gyms, you see so many people with a shake in their hands. Whey protein and casein are fully compatible, so their intake is not mutually exclusive.

Casein, just as other foods and supplements, should be taken in the right measure, recommended by a nutritionist or a dietician.