Peptides and proteins in whey and their benefits for human health

Review Article

Austin J Nutri Food Sci 2014;1(1): 1002.

Peptides and proteins in whey and their benefits for human health

Rie Tsutsumi1* and Yasuo M. Tsutsumi2

1Department of Nutrition, Institute of Health Biosciences, University of Tokushima, Japan

2Department of Anesthesiology, Institute of Health Biosciences, University of Tokushima, Japan

*Corresponding author: : Rie Tsutsumi, Department of Nutrition, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima Japan 770-8503

Received: December 12, 2013; Accepted: December 27, 2013; Published: December 28, 2013


Whey protein is derived from milk or the watery by–product of cheese production and is rapidly digested and absorbed. In addition to vitamin–binding proteins and several enzymes, whey protein contains a number of bioactive components including beta–lactoglobulin, alpha–lactalbumin, serum albumin, immunoglobulin, and lactoferrin. These components demonstrate a range of immune enhancing and antioxidant properties that result in effects on hypertension, cancer, hyperlipidemia, and virus infections. The conversion of the amino acid cysteine to glutathione can partially explain these effects. Further, whey protein is a great source of branched chain amino acids, which are particularly useful for athletes and sarcopenic conditions. In this review, we summarize the characteristics of whey protein and the recent findings regarding the effects of whey protein on specific conditions⁄disorders.

Introduction and Background

Epidemiological studies indicate that the consumption of milk and dairy products contributes to a reduction in the incidence of metabolic diseases [1,2]. Dairy proteins in milk are composed of approximately 80% casein and 20% whey protein. Whey protein is found in the liquid material created as a by–product of cheese production during which the watery portion of milk is separated from the curds. Advances in processing technology have resulted in a number of different finished whey products with varying nutritional profiles.

Whey protein seems to be more effective in physiological systems than casein, as a result of faster digestion and absorption kinetics, in addition to the presence of bioactive components [3]. The molecular structure of casein is easily hydrolyzed by enzymes in the gut and metabolized to simple structures that can be easily utilized by the body. Whey protein is hydrolyzed at a slower rate and maintains its function in the gut; therefore, it is retained in the intestines for a longer period of time. Boirie et al. hypothesized that the absorption rate of dietary amino acids in the gut varies according to the type of ingested dietary protein; as a result, postprandial protein synthesis, breakdown, and deposition are also affected [3]. To determine this, the authors provided a single meal containing 2 intrinsically 13C–leucinelabeled milk proteins, casein and whey proteins, to healthy adults. Whey proteins are considered to be “fast proteins” in that they reach the jejunum quickly after entering the gastrointestinal tract. Once in the small intestine, whey undergoes hydrolysis slowly, enabling greater absorption over the length of the small intestine. The rate of protein digestion and amino acid absorption from the intestines has a major effect on whole body protein anabolism following a single meal, and slow and fast proteins modulate the postprandial metabolic response, a concept that can be applied to wasting situations.

Whey protein is used in a variety of foods, including ice cream, bread, and infant formula. It has also been used to replace fat in a number of products. With its high protein quality score and branched chain amino acid (BCAA) content, whey protein has also long been popular in the exercise industry as a muscle–building supplement [4,5]. In comparison to all other structural animal proteins, whey proteins provide the greatest amount of BCAAs [6], which are hydrolyzed more easily than others, and increase the postprandial plasma BCAA levels within minutes [7,8].

Further, whey protein may act as an appetite suppressant and aid in the control of blood sugar [9,10]. However, research suggests it may have far wider applications as a functional food in the management of conditions such as cancer, hepatitis B, human immunodeficiency virus (HIV) infection, cardiovascular disease, osteoporosis, and even chronic stress [1]. Whey protein might also help prevent some hereditary conditions, such as a predisposition to allergies[11].

More recently, Melnik et al. reported that milk is not just a food but appears to represent a more sophisticated endocrine signaling system that activates mTORC1 via special maternal milk–derived dietary messengers controlled by the mammalian lactation genome. The BCAAs in the milk proteins and exosomal miRs produced by the mammary gland appear to augment mTORC1 signaling for postnatal growth [12].

Whey peptides are powerful isolates of amino acids derived from much longer whole whey protein molecules. These isolated whey peptides provide the following benefits: increased release of insulinlike growth factor, improved overall endocrine hormone response [9,13], increased nitrogen utilization and retention [14,15], increased intracellular glutathione and anti–aging antioxidants [16,17], improved immune function [18,19], improved gastrointestinal health [20,21], and increased rate of muscle growth [22,23]. Here, we summarize the characteristics and clinical indications of whey protein⁄peptide from recently published trials and studies.

Analysis and Interpretation

Biological components

From the standpoint of nutrition and food science, whey proteins, which are rich in essential amino acids, are of a higher biological value than the majority of proteins in the diet. Further, whey protein is the richest natural source of BCAAs and has a high bioactive value. In addition, Aydin recently found that adropin, nesfatin–1, apelin–12, des–acyl ghrelin, and salusins in cheese whey were higher than in the corresponding milk peptides and plasma of dairy cows, with the exception that salusin alpha and acylated ghrelin in milk were the same as that of the corresponding cheese whey concentration and plasma of dairy cows [24].

The nutritional value of proteins is determined by their ability to supply nitrogen through the appropriate balance of essential and non–essential amino acids. The biological value is the ratio of the amount of nitrogen that is consumed to the amount of nitrogen that is absorbed, and this value is 74 for soy protein, 71 for casein, and 104 for whey protein. The protein efficiency ratio indicates the increase in body weight associated with an intake of 1 g protein, and the protein efficiency ratio is 2.0 for soy protein, 2.5 for casein protein, and 3.0 for whey protein. Protein–related nutritional status is assessed using growth in infants and children, while the maintenance of nitrogen balance plays a critical role in adults. The proteins in whey have a variety of roles and immune–related functions, which are discussed further in the following paragraphs (Table 1).

Citation: Tsutsumi R, Tsutsumi YM. Peptides and proteins in whey and their benefits for human health. Austin J Nutri Food Sci 2014;1(1): 1002. ISSN: 2381-8980.