Together with casein, whey is the dominant protein found in milk. Whey protein makes up approximately 20%, while the rest is casein.
Whey is typically separated from casein using a series of filters and then purified through an iron exchange process, before drying into a powder. This powder is then used as a dietary supplement.
Whey is classified as a complete protein as it contains all nine essential amino acids. It is also low in lactose. Whey protein offers a range of health benefits and is particularly popular with athletes and body builders for supporting muscle mass.
Different types of whey protein
Whey protein is broken down into three main types that contain a mixture of bovine serum albumin, alpha-lactalbumin, beta-lactoglobulin, and immunoglobins. These include whey protein hydrolysate (WPH), whey protein isolate (WPI), and whey protein concentrate (WPC):
WPC – The protein content of WPC can be variable, ranging from 30% through to 90%. It contains low concentrations of lactose (carbohydrates) and fat.
WPI – More highly processed compared with WPC, this form of whey protein lacks lactose and fat. Protein is typically concentrated at 90%.
WPH – This is the easiest form of whey protein to digest. This is because it has undergone a process called partial hydrolysis which is a prerequisite for the body to effectively absorb the protein. WPH is often used in infant formulas and medical protein supplements because of its reduced allergen risk and easy digestion.
Why is whey protein advantageous for muscle building?
Exercising, especially resistance training, places significant pressure on muscles. During these work outs, the muscles are slightly damaged. This damage occurs at the fibrous level and is a natural process designed to facilitate increased muscle re-growth and greater strength. Following resistance training the body undergoes muscle breakdown and protein synthesis. This period is known as the “anabolic window”. During this time, the body is craving energy to help repair and build muscles. At the same time, the body is highly receptive to protein absorption.
The high protein content of whey and its ease of absorption make it ideal for helping to boost muscle repair and building following exercise. With all essential amino acids available in whey protein, the muscles have everything they need to support healthy development.
Several studies have demonstrated the positive effects of whey protein on muscle building when taken in association with resistance training1, 2. Research shows that supplementation with whey protein during resistance training increases lean tissue mass faster compared with resistance training alone. Furthermore, whey protein supplementation has been shown to significantly decrease body fat and increase strength and lean body mass faster compared with supplementation with casein.
Whey protein is considered ideal for pre-workouts because it gets into the body quickly and can provide an energy boost to support resistance training. Following a workout, whey protein should be taken in conjunction with a carbohydrate. This helps aid recovery and muscle building, plus replenish glycogen and glucose levels.
Other whey protein health benefits
In addition to supporting muscle growth, whey protein has other benefits. It can help with weight loss, and lower cholesterol and blood pressure. Whey protein also supports strong antioxidant activity that boosts immune function and may help to safeguard the body from cancer and other diseases and illnesses.
There is some evidence that regularly taking whey protein may assist with weight loss. In one study, participants that took a specialised whey formula (Prolibra) preserved a higher percentage of lean muscle mass and lost significantly more body fat compared with the control group3.
Prolibra is a whey fraction with a high concentration of milk calcium, bioactive peptides, and leucine. The amino acid leucine is a well-known appetite suppressant. This can help to lower calorie intake and stimulate weight loss.
Another study has found that whey protein can help to reduce ghrelin secretion4. Ghrelin, the “hunger hormone”, is secreted when the stomach is empty and helps to signal the body to eat. In Bowen and colleagues study, obese men who consumed beverages containing whey protein had significantly lower levels of ghrelin for up to four hours. This significantly reduced appetite.
There is a growing body of research that suggests whey protein may have important anti-cancer benefits. Studies show that whey protein can increase glutathione concentration (a powerful antioxidant), plus exhibit antitumor activity 5, 6. Whey protein can have overall health benefits by supporting better immune function.
Lower LDL cholesterol
One study has shown that whey protein may help to lower bad cholesterol levels and better protected the body from heart disease. After 12 weeks of supplementation with either whey protein, casein, or glucose (control), participants receiving whey protein had lower LDL cholesterol7.
People with high blood pressure may benefit from whey protein supplementation. One study has shown that when whey protein is added to beverages it can lower blood pressure in individuals with elevated diastolic and systolic blood pressure8. This may help to reduce the risk of heart attacks or strokes.
Initial research suggests that whey protein may help children suffering from asthma. In this small study, children that received whey protein had higher concentrations of glutathione compared with the control group. As a result, these children exhibited an improved cytokine response in atopic asthma9.
How much whey protein should I take?
Like all supplements, the amount of whey protein you should take depends on several factors including the type of whey protein (WPC, WPI, or WPH), the concentration of the supplement, individual body weight, and the purpose of supplementation.
As a very rough guide, the amount of protein needed daily per pound of body weight is:
- Recreational athletes – 0.5-0.75 grams
- Competitive athletes – 0.6-0.9 grams
- Teenage athletes – 0.8-0.9 grams
- Athletes building muscle mass – 0.7-0.9 grams
It’s always a good idea to consult with a nutritionist or your doctor before starting any supplementation program.
Potential side effects of whey protein supplementation
Generally most people don’t suffer adverse reactions to moderate whey protein supplementation. However, individuals allergic to milk may have a negative reaction to whey.
Excessive consumption of whey protein may cause cramps, stomach pain, nausea, low appetite, headaches, and fatigue.
- “Darren G. Burke, Philip D. Chilibeck, K. Shawn Davison, Darren G. Candow, Jon Farthing, and Truis Smith-Palmer. (2011). The Effect of Whey Protein Supplementation With or Without Creatine Monohydrate Combined With Resistance Training on Lean Tissue Mass and Muscle Strength”. International Journal of Sport Nutrition and Exercise Metabolism. Volume 11, 349-364.” ↩
- “Paul J. Cribb, Andrew D. Williams, Michael F. Carey, and Alan Hayes. (2006). The Effect of Whey Isolate and Resistance Training on Strength, Body Composition, and Plasma Glutamine. International Journal of Sport Nutrition and Exercise Metabolism. Volume 16, 494-509.” ↩
- “Joy L Frestedt, John L Zenk, Michael A Kuskowski, Loren S Ward, Eric D Bastian. (2008) A whey-protein supplement increases fat loss and spares lean muscle in obese subjects: a randomized human clinical study. Nutrition & Metabolism. Volume 5, Issue 8 doi: 10.1186/1743-7075-5-8.” ↩
- “Bowen, J. Noakes, M. and Clifton, P. (2007). Appetite hormones and energy intake in obese men after consumption of fructose, glucose and whey protein beverages. International Journal of Obesity. Volume 31, Issue 11, 1696-703.” ↩
- “Bounous, G. Batist G. Gold, P. (1991). Whey proteins in cancer prevention. Cancer Letters. Volume 57, Issue 2, 91-4.” ↩
- “Bounous, G. (2000). Whey protein concentrate (WPC) and glutathione modulation in cancer treatment. Anticancer Research. Volume 20, Issue 6C, 4785-92.” ↩
- “Pal S, Ellis V, Dhaliwal S. (2010). Effects of whey protein isolate on body composition, lipids, insulin and glucose in overweight and obese individuals. The British Journal of Nutrition. Volume 104, Issue 5, 716-23.” ↩
- “Fluegel, S, Shultz, T., Powers, J., Clark, S. et. al. (2010). Whey beverages decrease blood pressure in prehypertiensive and hypertensive young men and women. International Dairy Journal. Volume 20, Issue 11, 753-60.” ↩
- “Lothian JB, Grey V, Lands LC. (2006). Effect of whey protein to modulate immune response in children with atopic asthma. International Journal of Food Sciences and Nutrition. Volume 57, Issue 3-4, 204-11.” ↩