Casein protein is found in cow's milk, accounting for about 80 % of its total protein content. It is characterised as a slowly digested protein, which means that your body digests and absorbs it at a slower rate than other proteins, for example, whey.
Casein protein derives from cow’s milk and undergoes a process where it is separated from the whey. Following this separation, it can be further refined to create a powdered supplement that has become highly popular in fitness communities.
Foods with casein
Casein protein is most abundant in dairy products, particularly milk and cheese. However, it can also be found in smaller quantities in other dairy-based products such as yoghurt or cream.
Beyond these typical sources, casein also makes its way into many processed foods. These can include certain types of bread, processed meats, and even meal replacement bars or shakes. This is because it is not only a source of protein, but it also has beneficial properties for food production, such as emulsifying and binding capacities.
Casein in milk
As mentioned earlier, casein protein in milk, specifically cow's milk, makes up approximately 80 % of the total protein content. The exact proportion varies depending on the type of milk (skim, low-fat, whole) and the breed of cow it comes from.
- In general, whole milk contains 3.4 grams of protein per 100 grams, equalling 21.8 % of the total energy value.
- Low-fat milk (1.5 % fat) also contains 3.4 grams of protein per 100 grams, but in this case, protein makes up 29 % of the total energy value.
- Skim milk contains 3.5 grams of protein per 100 grams, making up 40.5 % of the total energy value.
Casein in cheese
Cheese is essentially concentrated milk, so it is no surprise that it is a rich source of casein protein as well. The actual content varies significantly depending on the type of cheese, but generally, hard cheeses contain more of it than soft ones.
For instance, cheddar cheese is a hard cheese that contains about 25 grams of protein per 100 grams, most of which is casein. Given the high concentration, cheddar cheese can be an option for those looking to increase their protein and casein intake. Its energy contribution is 26.5 % of the total energy value. However, be mindful of the total energy content of especially full fat cheeses.
Brie is considered a soft cheese, and a 50 % FIDM-variant contains about 19.8 grams of protein per 100 grams. Protein accounts for 24.5 % of the total energy value. Although this is slightly less than what you would find in hard cheese like Cheddar, a considerable proportion of this protein is still casein.
Casein vs whey protein
Though both proteins derive from milk, the difference between whey and casein lies in the digestion time. While casein is slowly digested, whey is digested faster, meaning it is absorbed quickly into the bloodstream.
Whey protein is typically used immediately after a workout due to its quick absorption rate. Casein protein, on the other hand, is often taken before bedtime due to its slow-release properties.
The choice between the two really depends on your specific dietary needs and fitness goals. Some people may prefer one over the other, while many find it beneficial to use both at different times.
What does casein do?
Casein, like all proteins, contributes to the growth and maintenance of muscle mass and normal bones. The slow-release time makes it particularly beneficial for muscle growth and recovery.
If this topic piqued your interest, you should also check out our guide to protein types and high-protein foods to find more information.
