If you’re into strenuous workouts, bodybuilding, weightlifting or work in the dairy industry, you’re probably familiar with casein protein powder. Like whey protein, the supplement is milk-derived. Though percentages may vary, all mammals—including humans, cows, goats, sheep, mice and narwhals—have whey and casein proteins in their milk. Cow’s milk—which humans consume the most—and other mammalian milk contain 80 percent casein protein and 20 percent whey protein (x).
Research History on Milk Protein
Milk history tells us that farmers stored milk in goats’ and sheep’s stomachs for sustenance when they spent time in the fields tending livestock. When they drank it, there was coagulated residue at the bottom and possibly mixed in. Researchers later discovered the solid residue was due to an enzyme from calves’ stomachs. Ancient Egyptians discovered that the proteinaceous substance could also be used as a base for paints and glue (x).
In the 19th century, researchers developed an interest in learning about milk and its proteins. In 1814, Swedish chemist Jon Jacob Berzelius was the first to unravel the casein structure. In 1897, Bavarian chemist Adolf Spitteler discovered he could convert milk into solids with formaldehyde, thanks to his cat. The pet accidently spilled the chemical into his bowl of milk. Spitteler eventually filed a patent for this new, plastic polymer in 1899 and companies began to use it in the manufacture of buttons, buckles, jewelry, pens and paper coatings (x, x, x).
Research History on Protein Supplements
Casein powder didn’t get much consideration as a supplement until the 1950s when companies scrambled to find the perfect supplement for bodybuilders and weightlifters. In the 1960s, nutritionist Irving Johnson, who later changed his name to Rheo H. Blair, began selling an unpleasant-tasting casein-derived protein powder. The quality, taste and texture of supplements didn’t improve until the food industry stepped in.
By the 1990s, research grew more extensive and intensive as regular individuals joined athletes in the desire for optimum health and fitness (x). Today casein is still used in non-edible products such as soaps, insecticides and tooth enamel. It is also used in edible items like food thickeners and binders, coffee creamers and medicines. Research on its benefits as a dietary supplement continues as well.
What Is Casein Protein?
Casein protein is the main ingredient found in cheese. As a matter of fact, the word comes from the Latin word for cheese, “caseus.” Casein is one of the best proteins for supplying us nutrients, including the essential amino acids our bodies cannot produce. It’s usually suspended in coagulated milk as a porous, insoluble micelle (x).
Besides protein, the casein micelle contains phosphorus, enzymes and other constituents. This aids in the coagulation and formation of complex subunits with calcium (x, x). Prior to domestication, cows’ milk contained one kind of casein, A2 beta. About 8,000 years ago, however, a gene-mutation occurred in the Holstein breed, producing an A1 beta casein. As the superior Holsteins mated with other breeds, the mutation spread. Not only were other variants created, but overtime the A1 variant became dominant. Some countries like Africa and Australia only have cows producing the A2 beta casein milk (x).
How Is Casein Protein Made?
Casein protein is made by one of two methods (x):
- Curdling, through the natural fermentation of the milk sugar lactose by adding the bacteria streptococcus lactisi (x)
- Conversion into solids by adding diluted hydrochloric acid or sulfuric acid (x)
- Treating warm milk with an extract of the coagulant protease rennet to depolymerize the phosphoprotein (casein) compounds, so they can recombine with calcium and other molecules to form larger and denser paracaseinate units or clots (x, x)
What Foods Contain Casein Protein?
Casein protein is found in dairy products. Foods with casein tend to have a moderate to high protein content (x). For example:
- Low-fat milk or skim milk
- Ice cream
Casein Protein vs. Whey Protein
So, what is the difference between whey protein and casein protein? Casein and whey have a few similarities. Both are high-quality milk proteins, both contain all the essential amino acids that the human body needs and both are byproducts of cheese-making. The differences have mostly to do with physical characteristics, quantity, process and function.
A few more questions you could have: How long does casein last? How long does whey protein last? How long does casein protein take to digest? Quite simple. Once the casein releases the amino acids into the bloodstream, absorption by muscular tissues is a slow and steady process that usually takes hours (x). Unlike casein, when whey protein enters the bloodstream, it travels to the muscles at a much faster rate (x). Casein is a slow-digesting protein. It clots once it reaches the stomach, causing amino acids to take longer to enter the bloodstream (x).
When it comes to amino acid totals, casein protein has more histidine, methionine and phenylalanine. Whey has more leucine, isoleucine and valine (x). Whey’s immunoglobulins have antimicrobial and antioxidant abilities. Casein’s peptides (short-chained amino acids) boost the immune and digestive systems (x, x).
What Is Casein Protein Powder Used For?
You can use casein protein for (x):
- Faster muscle-building
- Muscle growth
- Muscle recovery after a strenuous workout routine
- Procure healthy bones (because of its calcium component)
- Maintain healthy weight
However, always consult your doctor before taking dietary supplements for safety and to avoid unwanted side effects.
Let’s take a closer look at how muscle building occurs:
The leucine amino acid in casein protein triggers protein synthesis, which then helps build new muscle (x). The slow-release of leucine (and other amino acids) into the bloodstream versus its quick-release in whey protein feeds our muscle fibers at a steadier, more effective pace (x).
Casein protein is anti-catabolic, meaning it has the ability to prevent or delay the breakdown of lean muscle tissue. Bodybuilders and weightlifters may prefer to have an anti-catabolic than a catabolic reaction because the latter breaks down muscle fibers (x). Casein protein may also induce quick muscle recovery (x).
Proteins are the “building blocks” of the body’s cells. These long peptide chains of amino acids provide structure and are involved in all of the body’s chemical reactions (x). But what else can it do? What are some other benefits of casein protein?
We know that casein protein is involved in the building of new muscle tissue, promoting the growth of lean muscle, repairing muscle mass, enhancing physical strength and performance and preventing muscle tissue breakdown. But it has other useful properties thanks to its amino acid makeup (x).
Amino Acid Makeup
Casein contains all nine essential amino acids our bodies cannot make—leucine, isoleucine, lysine, valine, histidine, phenylalanine, methionine, tryptophan and threonine. That’s why it’s considered a complete protein. Cow’s milk casein contains the highest quantity of leucine, valine and lysine (x).
- Leucine and valine aid in the growth and repair of tissues and reduce muscle breakdown.
- Valine helps the nervous system and cognition.
- Lysine combines with vitamin C to form a compound that helps muscle tissue absorb more oxygen and delay fatigue during workouts.
Calcification of the Mammary Gland
When calcium builds up in breast milk ducts, it calcifies. One of two forms of calcification can occur: macro or micro. Macrocalcification occurs in about 50 percent of women past the age of 50. Beside age, buildup could be the result of breast injury, inflammation, cancer or radiation treatment for cancer. Most calcifications, however, are harmless and usually found during routine mammograms (x, x).
When milk is consumed, gastric acid in the stomach coagulates or gels the casein. The process slows amino acid breakdown and digestion. This leads to a constant flow of amino acids into the bloodstream and our cells get to use them more efficiently (x).
Why Take Casein Protein Powder?
If you’re an athlete or health-conscious individual, casein protein may help you accomplish your goals because for one, digestion is slower (x). The flow of amino acids into the bloodstream is slow, continuous, occurs for hours and sets up more efficient use (x). It increases muscle strength and prevents injury (x). If taken at night, as recommended, your muscle mass may even increase while you sleep (x, x).
How to Take Casein Protein Powder
The recommended dosage for casein protein powder as a dietary supplement is 30 g per day. It can vary, depending on the individual. Always consult your doctor before taking dietary supplements. BulkSupplements casein protein powder has been ranked as one of the top 12 casein protein powders of 2020 by Healthline. It has been named the best unflavored casein protein powder for 2020.
When to Take Casein Protein
Studies show that the best time to take casein protein powder supplement is right before bed. The slow release of amino-acids works best on building and healing muscle tissues while you sleep (x). Like all proteins, casein protein is satiating, meaning it has the ability to make you feel full. Its satiety value, however, is greater because it’s a complete protein (x). There are a number of research studies that suggest casein protein has muscle recovery and satiety properties (x). But remember, always consult your doctor before taking any dietary supplements.
Possible Side Effects of Casein Protein Powder
Possible side effects of casein protein include:
- Bloating, nausea and headaches from overconsumption (x)
- Kidney issues, especially if the patient already has kidney disease (x)
- Liver damage, especially in those who currently have liver disease (x)
- Increased risk of endometrial and other types of cancers (x, x)
- Increased risk of childhood diabetes and pancreatic damage (x)
- Viral breakdown of protein leading to excess mucus & congestion of the respiratory system (x)
- Lactose intolerance (x)
Casein Protein Allergies
- Itchy eyes
- Stomach pain
- Respiratory congestion
- Anaphylactic shock (which could be fatal)
Like whey protein, casein protein is derived from milk. It’s a complete protein, so it contains the nine essential amino acids the body needs, but cannot make. Casein is slow-digesting, anti-catabolic, delays protein breakdown in the stomach and provides the body’s muscle tissues with a steady stream of amino acids for recovery after strenuous physical activity. Casein protein also increases muscle growth, strengthens muscle fibers and helps promote overall health and fitness.
Casein protein supplements are generally safe to consume and a good source of daily protein-intake. It works best if consumed before bedtime. Most of its side effects are due to overconsumption or pre-existing conditions. Be sure to consult your health professional before taking any dietary supplements
Disclaimer: These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.