Casein: What is it?
Casein is the main protein in cow’s milk. The word casein derives from the Latin word causes – which means cheese. Supplements based on this protein are sold as a way to prevent muscle catabolism, particularly when taken at night before bed. Some even dare to call it the slow protein due to its differences in absorption percentage. Is this true?
Unlike whey protein, casein is absorbed slowly. For this reason, most manufacturers suggest taking this sports supplement at night or during periods of fasting. It is believed that one of the effects of slow protein is to prevent muscle breakdown. However, recent research has confirmed that this is a myth.
Is casein a slow protein?
Studies state that differences in the rate of absorption of milk protein versus other proteins exist. In a study where two groups of people took isolated casein and the other Whey protein, leucine levels were higher and sustained over time¹.
Compared to other supplements such as Whey Protein, the absorption rate of isolated milk protein is lower. However, it is essential to know that these studies confirmed no significant effects on avoiding muscle destruction from taking casein at night.
Effects of isolated milk protein on muscle growth
When it comes to muscle growth, the importance of protein cannot be denied. However, when talking about proteins, it is more important to focus on quality and quantity than on absorption rate. Casein is a relatively complete protein, although there are others of lower price and higher quality, such as egg protein.
There is no evidence that a slow rate of protein absorption is effective in achieving significant results in enhancing muscle growth. Recommendations for taking casein overnight are based primarily on manufacturers’ recommendations.
Aminoácidos BCAA vs caseína vs Whey Protein
The BCAA amino acids are one of the most used in the processes of muscle toning supplements. These types of accessories are leucine and glycine concentrates. Compared to casein, they are more effective in avoiding the muscle destruction processes when running workouts to lose body fat.
Compared to Whey protein, the amino acid content of casein is only 15-30% higher than whey protein. However, the cost of casein is at least 30% higher. In conclusion, it is more effective to take whey protein in bulking processes and bcaa amino acids in toning processes.
How to take casein?
If you still decide to take casein. Manufacturers recommend taking about 5 g of slow protein before bedtime, ideally at night and on an empty stomach. Taking this supplement in combination with a carbohydrate source (which increases its absorption rate) is pointless.
Casein – Contraindications and Side Effects
Casein is considered a safe sports supplement for health. The contraindications of milk protein are for people with a milk allergy, and its most common side effects are digestive disorders, diarrhea, skin rashes, and nausea.
Importantly, milk allergy and lactose intolerance are not the same. Milk allergy refers to the body’s overreaction to milk protein: casein—lactose intolerance to the sugar present: lactose.
Casein, also called slow protein, is the protein found in the highest proportion in milk. There is no solid scientific evidence on the benefits of taking casein for muscle growth. Emphasizing the quantity and quality of protein is more effective than giving importance to its absorption rate. However, slow protein is considered a safe supplement for health, and manufacturers recommend taking it at night.