Casein

Casein is a complete protein , which contains all the essential amino acids needed for muscle protein synthesis. This slow protein is absorbed over several hours, for a gradual diffusion of amino acids. This property makes casein a very powerful anti-catabolic protein . Consume alone or mix with whey according to your needs!

What is casein?

Casein , derived from the Latin word "caseus" meaning cheese, is a major protein found in cow's milk. It plays a structural role in adding creaminess to milk and is widely used in the cheese industry to add consistency and texture to cheese, yogurt, and other dairy products. It is also used to prevent maderization of white wine (1). Making up about 80% of the protein in whole milk (compared to 20% for whey protein), casein is a rich source of essential amino acids such as serine, lysine, and leucine . It is also consumed as a dietary supplement. Casein is distinguished by its slow digestion , which gradually releases amino acids and peptides over a long period of time. This property makes it a popular choice for taking before bed, as it helps support nighttime anabolism and muscle repair during sleep. More satiating in nature, casein offers a sustained release of nutrients , which are absorbed more quickly. It is not necessarily better or worse than otherprotein powders : casein simply complements the use of whey by providing a longer-lasting source of protein , beneficial for those looking to maximize the anabolic effect of protein throughout the night.

What are the different types of casein?

Calcium caseinate

Calcium caseinate is a form of casein made by adding calcium to acid casein. This process changes the structure of the protein, making it more soluble in water than micellar casein. This improved solubility makes calcium caseinate a popular ingredient in dietary supplements and nutritional products because it mixes easily with liquids . However, due to its processing, calcium caseinate is absorbed slightly more quickly by the body than micellar casein, although it is still relatively slow compared to whey protein.

Micellar casein

Micellar casein is the most natural and least processed form of casein, obtained by gentle filtration of milk that preserves its micelle structure. These micelles are protein aggregates that digest very slowly, releasing amino acids over a long period of time (often up to 7 hours). This is why micellar casein is often consumed before bedtime, to provide a prolonged supply of protein during the night, promoting muscle recovery and preventing catabolism (muscle breakdown).

Athletes: what are the benefits of casein?

Sustained release of amino acids

Casein, especially micellar casein, is digested slowly by the body . After ingestion, it forms a gel in the stomach, which slows down the digestion and absorption of amino acids into the blood. This prolonged release (up to 7 hours as mentioned above) ensures a continuous supply of amino acids . This is ideal for preventing muscle catabolism during periods when no food is consumed, for example during the night.

Nighttime recovery support

The slow release of amino acids during sleep promotes nighttime muscle recovery . While the body is resting, muscles continue to receive the nutrients needed to repair micro-damage caused by training, which can lead to better recovery and greater muscle gains in the long term.

Anti-catabolic effect

Unlike fast-digesting proteins like whey (which rapidly increase blood amino acid levels), casein helps maintain these levels stably over an extended period of time. This anti-catabolic effect is crucial for athletes looking to preserve muscle mass, especially in situations where protein intake is spaced out, such as between meals or during overnight fasting. Casein helps minimize muscle protein breakdown, thereby promoting better maintenance of lean mass.

Increased feeling of satiety

Because of its slow digestion , casein can also contribute to a feeling of prolonged satiety. This can be beneficial for athletes in a weight loss or cutting phase, where appetite management is essential. By delaying the feeling of hunger, casein can help you control your total caloric intake , while providing the protein needed to preserve your muscle mass.

When to take casein?

Before bedtime

One of the most common times to consume casein is right before bed . Due to its slow digestion, casein gradually releases amino acids into the bloodstream over several hours. This mechanism helps support muscle repair and growth throughout the night, preventing muscle catabolism during the overnight fast.

Between meals

Casein can also be taken between meals , especially when there is a long period between main meals. Its satiating effect and prolonged release of amino acids help maintain a constant protein intake , which can be useful for those looking to optimize protein synthesis throughout the day.

After a late workout

If you’re training late at night, casein can be a good choice for a post-workout snack . While whey is often preferred for quick recovery due to its rapid digestion, casein can provide extended protein support throughout the night to maximize muscle recovery.

What should you supplement your casein intake with?

Whey concentrate and whey isolate are fast-digesting proteins , ideal after training to immediately provide amino acids to the muscles. Hydrolyzed whey , which is pre-digested, allows for even faster absorption, making it an excellent choice for ultra-fast recovery after intense effort. Clear whey , light and refreshing, is also quickly digested and is ideal for a post-workout snack. It combines well with casein to ensure continuity in protein intake, from short term with whey to long term with casein. For vegans or those avoiding dairy products, vegan whey offers an effective alternative. It can be used in addition to casein to diversify protein sources and support amino acid intake throughout the day. By combining casein with these different forms of whey, you optimize immediate muscle recovery while ensuring a prolonged protein intake for better muscle growth.

Sources:

(1) https://pubmed.ncbi.nlm.nih.gov/2236098/

(2) https://pubmed.ncbi.nlm.nih.gov/32698256/