Whey protein: some facts you need to know

Among the dairy proteins, whey protein has recently received much attention from the scientific community due to its positive effects on health. Whey protein has been associated with increased muscle protein synthesis, satiety, and weight management. This dairy protein is available in several different forms, including whey powder, whey protein concentrates, whey protein isolates, reducedlactose whey, and demineralized whey. Whey protein is a highquality complete protein that is easily digestible. Complete proteins contain all of the essential amino acids that the body requires to build proteins. Essential amino acids are important because they can not be synthesized from the amino acids that are already present in the body and therefore must be consumed in the diet. Whey proteins are also a rich source of branched-chain amino acids (BCAA), which are a subgroup of the essential amino acids. The BCAAs include valine, leucine, and isoleucine, and can be used as an energy source in skeletal muscle and also contribute to the synthesis of new muscle tissue. Among the BCAAs, leucine is unique, as it has been shown to be an independent stimulator of skeletal muscle protein synthesis through the regulation of gene expression The amino acid profile of whey protein in comparison with other protein sources demonstrates why it is a great protein source for individuals to include in their diet. Other protein sources, for example most vegetable proteins, are not complete proteins because they do not contain all of the essential amino acids. In some cases, these foods must be consumed with another protein source in order for an individual to get all of the essential amino acids. The BCAA content of whey protein is greater than other protein sources, with whey protein isolate, egg protein, soy protein isolate, and wheat protein having BCAA contents of 26, 20, and 15% respectively. Leucine content also varies across the different protein sources, with whey protein isolate, egg protein, soy protein isolate, and wheat protein containing 14, 8.5, 8, and 7%, respectively. The high content of BCAAs, and more specifically leucine, supports the inclusion of whey protein in the diet. Consumption of whey protein increases protein synthesis, which over time can lead to the production of new muscle tissue. When routine consumption of whey protein is combined with a long-term resistance-training programme in young adults, an increase in muscle can occur, which may improve body composition. For example, one study found that supplementation with 1.2 g of whey protein per kg of body weight 9g/kg BW) in combination with resistance exercise resulted in a greater increase in lean muscle mass than supplementation with an isocaloric carbohydrate beverage. Current research supports a combination of protein intake and resistance exercise over a carbohydrate beverage and/or resistance exercise for a more effective increase in lean muscle tissue.

Not just for exercisers:

The issue of muscle loss with aging, referred to as sarcopenia, is becoming an important public health concern. Maintenance of muscle mass through increased protein levels in elderly adults could extend functional capacity, independence, and quality of life. Emerging research, particularly in individuals around the age of 40, where the decline in muscle mass becomes more pronounced, show that individuals throughout their lifespan can benefit from a long-term increase in muscle protein synthesis. The concept of satiety, defined as the feeling of fullness after eating, and its implications on weight management have received a lot of attention from the scientific community. It has been postulated that dietary protein may have a positive role in stimulating satiety, and research suggests that protein is more satiating than carbohydrate or fat. Studies have documented this either in the context of a single meal, or the overall diet (i.e. subjective ratings of fullness and free-access feeding energy intake after a test meal). Research on middleaged women who exercised also suggests that higher-protein diets compared with adequate-protein diets with equal amounts of caloric restriction may contribute to weight management by improving the quality of weight loss through preservation of lean body mass and decreasing fat mass. Further, there was a trend for a greater preservation of lean mass with the higher-protein group. This research supports evidence suggesting that protein is more satiating than other macronutrients and that the satiating effects of a longer-term, higher-protein diet may eventually lead to a reduction in body fat, thus playing a role in weight management. Scientists are continually working to investigate additional potential health benefits of whey protein. In addition to improvements in muscle mass
   and body composition, and contributions to satiety, preliminary evidence has also suggested a benefit of whey consumption on blood pressure, immune function, and inflammation. The scientific evidence supporting whey’s role in health is still emerging and will continue to expand. Whey protein concentrate is included in a variety of food and beverage products, including confectionaries, soups, snack foods, clinical nutrition mixtures, and infant formulas. Additionally, whey protein isolates are used in sports beverages and powdered beverages. Although whey protein isolate contains a greater amount of protein (90%) than whey protein concentrate (35-80%), few studies distinguish the health benefits of each form to provide rationale for use of one form over the other. The use of whey protein concentrate instead of whey protein isolate may be due to practically and control of functional properties as a greater amount of whey protein concentrate will be needed to match the amount of protein provided by whey protein isolate.