Milk contains a number of specific proteins, primary protein being the casein. Basically, when casein is removed from milk, the protein left in the milk is whey protein. Whey is the watery portion of milk that separates from the curds when making cheese or when making paneer. Whey protein contains all nine essential amino acids and it is also low in lactose content. So it is the ideal source of protein for the young and old, the thin and the fat, as well as for those who are healthy or those who are recuperating from a disease.
Whey Proteins in Milk
Major whey proteins in milk are:
• Beta-lactoglobulin - although no definitive function is attributed to this protein, scientists believe it functions primarily for binding fatty acids and retinol.
• Alpha-lactalbumin - this protein is essential for milk synthesis.
Other whey proteins include :
• Immunoglobulins - these are antibodies especially high in colostrum
• Serum proteins
Whey is a rich source of amino acids leucine, isoleucine and valine. These amino acids help in the process of protein synthesis; consequently, they help in repair and growth of muscle tissue. That’s why whey protein is so popular with bodybuilders and athletes.
Another important amino acid in whey is cysteine. This amino acid helps boost the immune system.
Apart from the above mentioned, whey proteins also have many enzymes, hormones, growth factors, disease resistance factors, and other important components.
Another plus point for whey protein is that our body absorbs more whey protein than most other forms of protein, that is, they have high bioavailability. This is the reason infants and seniors alike can digest this protein easily.
Forms of Whey Protein
There are three forms of whey protein:
• Concentrate - This form of whey protein contains fat, lactose, and proteins in the range of 25 to 89 percent. Therefore, they are digested more slowly.
• Isolate - This form of whey protein contains almost no fat and lactose, and their protein content ranges from 90 to 95 percent. It is a rapidly digestible form of whey protein.
• Hydrolysate - This is the most digestible form of whey protein because hydrolysates are formed by breaking down the amino acids further into peptides. This is the fastest way we can provide our muscles with amino acids.
Whey Protein Benefits
Sat on a tuffet
Eating her curds (casein) and whey …’
This nursery rhyme indicates that over the centuries people have known and accepted the importance of milk components - casein and whey, as part of the healthy diet.
The health benefits of whey protein range from muscle building to reducing obesity to preventing many chronic diseases and disorders.
Increases Life Span
Reduced appetite and impaired nutrient absorption leads to inadequate nourishment in the elderly, which means they don’t get sufficient quality protein. And this is the reason why their muscle mass and bone mass decreases. They have low immunity and their cognitive ability declines. This called frailty syndrome.
Given the fact that intake of insufficient protein increases the risk of mortality in the aged, whey protein could be a possible solution to preventing frailty.
Whey protein contains leucine, isoleucine and valine that help prevent protein breakdown and stimulate protein synthesis.
Improves Gastrointestinal Immunity in Infants
Whey protein infant formula is a good option for babies that cannot be breastfed for some reason. Studies have indicated that whey fed infants (less than 2 weeks old) had richer beneficial gut microbes as compared to those on cow-milk formula. These microbes could possibly provide two important benefits:
• They improved gastrointestinal immunity by reducing colonization of harmful bacteria in the stomach and gut.
• They also decreased the risk of developing atopic disease.
Another study published in the journal Pediatrics indicated that whey formula could reduce infantile colic. Infantile colic is described when an infant cries for 3 hours at least 3 times a week for at least 3 weeks. The study showed that babies given whey formula cried at least one hour less per day as compared with babies given cow’s milk.
Builds Muscle Mass
Body builders and athletes are known to take whey protein shakes or supplements as part of their customized diet. This is because the branched-chain amino acid leucine (as already mentioned earlier) acts as a ‘signaling molecule’ to initiate protein synthesis and improve BMI in those who exercise.
Although studies on effect of whey proteins on muscle size and strength are limited, studies show that men engaged in resistance training improved their strength when they were given whey protein supplementation. For example, a study showed that muscular performance in men improved significantly when they were given 10g of whey protein supplements twice daily for 3 months.
Whey protein isolates are very high in proteins (approximately 95 percent) and contain almost no fat and sugars or lactose. This makes it an ideal food if you want to avoid putting on weight.
Further, scientists believe that whey contains calcium which along with other bioactive components in whey increase breakdown of fat cells and reduce formation of fat cells.
Unfortunately, whey proteins with or without calcium can only prevent obesity but do not really have any impact on those who are already obese or overweight.
Interestingly, new studies on whey protein show that inclusion of whey protein in the diet significantly decreases the incidence of colds and cold-related symptoms.
Researchers from University of Queensland, Australia, suggested a combination of lactoferrin and whey protein Ig fraction (LF /IgF) to be used as preventive supplement for colds.
Reduces Risk of Cardiovascular Disease
High fat diet and the preference for processed foods makes us prone to cardiovascular disease. We know that. We also know that milk must always be a part of a healthy diet.
A study published in the Journal of Dairy Sciences indicated that consuming fermented milk with whey protein concentrate can significantly increase HDL cholesterol, lower triglycerides, and lower systolic blood pressure.
Prevents or Lowers Risk of Diseases / Disorders
Whey proteins contain number of bioactive components that help prevent or lower risk of certain diseases.
For example, whey protein stimulates immunity and detoxifies potential carcinogens, thus preventing cancers.
Similarly, research has shown that whey protein supplementation for 8 weeks had variable effects of hepatitis virus infection.
Glutathione deficiency is one of the problems associated with HIV infection. Research has shown that 2-week oral supplementation of 45g of whey protein daily significantly increased glutathione levels in HIV infected people.
Whey protein increases bone mineral density and thus prevents osteoporosis.
Studies have also shown that whey protein improves cognitive function and coping ability in highly stressed individuals.
Last but not the least, whey protein has a protective effect on stomach lining. Studies have shown that alpha-lactalbumin in whey protein significantly reduces ulcerative lesions.
Side effects of Whey Protein
Whey protein maybe a super food with numerous health benefits but it certainly does have its share of side effects. Moderate amount of whey proteins actually do not show any adverse effects on us but side effects occur when whey protein is consumed in substantial amounts.
If you are allergic to cow milk, you most probably will also be allergic to whey protein.. The allergy is most often caused by beta-lactoglobulin.
Very high doses of whey protein can also cause stomach pains and cramps, reduced appetite, tiredness, headache, and nausea.