In the health & fitness industry, supplements have become a major part of obtaining optimal health. Everything from vitamins to synthetic hormones have lined the shelves and stocked our cabinets. Each of them has a list of claims that propose to do everything from preventing disease to creating the perfect body. Many of these claims are false, but some of them hold merit. Whey Protein is at the forefront of the supplement market. This product has claimed to improve immune function, athletic performance, reduce stress and improve the quality of life. Of all of the supplements that are available today, whey protein has held up to the scrutiny of western medicine. For these reasons, I feel that it can be a valuable asset in complimentary medicine. Throughout this paper, I will examine the evidence for the claims of whey to improve immune function, performance, and reduce stress to solidify its place in alternative and complimentary medicine.

PHYSICAL PERFORMANCE

            The bulk of the fitness industry has focused its attention on the reduction of obesity and achieving a picture perfect body. One of the biggest and most compelling claims toted by whey protein is its ability to favorably change body composition and improve athletic performance related to the onset of fatigue and force development. Recent research10, 3 has pointed to whey's ability, in conjunction with exercise, to reduce body fat while increasing lean mass. In a double blind placebo controlled study10, two groups were placed on identical training programs while one of the groups was given a whey protein supplement and the other a placebo made of casein protein. Casein is the other major protein found in milk.  The researchers found that the supplemented group saw reductions in body fat, and increases in strength and power, where as the control group saw little to no change in any variable from baseline. In fact, the control group saw a 5% increase in body fat while the supplemented group saw reductions of 4%.  It should be noted that the supplemented group did increase total daily activity by a much greater amount than the control group. This could account for differences in body fat.      

            In more current research, Cribb et. Al. found very similar results. In a randomized double blind placebo controlled study, two groups engaging in the same exercise program were given either a whey protein isolate supplement or a casein supplement as a control. The results were quite shocking. The supplement group gained an average of 5kg of lean muscle tissue as assessed by a DEXA, which can determine differences in tissue types. This means that these increases were not merely "lean mass" but actual increases in muscle fiber weight.  The control group saw meager results in comparison with an average increase of 1 kg in muscle weight. Cribb et al. also similar results to that of Lands et al. pertaining to changes in body fat. The supplemented group lost on average 1.5kg of fat mass while the control group experienced a small increase of .2kg in fat mass. The differences in gains in strength were as equally shocking.  Because of the nature of the program (maximal strength training), both groups increased their strength significantly. However, the supplemented group averaged 55kg greater in the barbell back squat, 64kg in the barbell bench press and 29kg greater in the cable pull down 1 repetition maximums. It is important to note that these studies used experienced resistance training individuals and not the previously sedentary.  These studies are landmark studies because they are among the only that compare different types of protein from the same whole food source and show their differing effects. They are also among the only studies to test only the protein with out other supplements included. Many others combine creatine monohydrate, which in itself will increase lean mass, strength and power outputs making them unsuitable for comparison. These confounding factors make available research limited, but what we do have is very compelling. All accounts point to improvements in physical performance and positive changes in body composition.

MODE OF ACTION

            Researchers have been intrigued by the differencing results from this different protein and have established a generally accepted answer as to why. Although casein and whey are derived from milk, they have very different chemical structures. Casein is very large and takes hours to digest4, 11. On the other hand, the protein molecules in whey do not even require gastric digestion8. They are dumped into the blood stream as they are presented to the stomach. This causes a very rapid increase in amino acid concentration in the blood. It is this rapid increase that stimulates protein synthesis4, which is one of the governing processes of muscle growth.  More muscle mass leads to greater strength. These two things would explain why the whey supplemented groups experience greater results than their control counter parts.

STRESS

            Another draw of staying fit through exercise is its ability to reduce stress. In fact, exercise has been shown to be as effective as certain medications in terms of reducing stress.  A second claim of whey protein is that it has the ability to reduce stress or improve ones mood. Recent research has confirmed this very claim¹². Serotonin is a chemical in the brain that is used to identify ones ability to adapt to stress. People who can produce more serotonin can cope better in stressful situations and display a better mood than people with lower levels of serotonin. The amino acid Tryptophan is the limiting factor in serotonin production. Whey protein possesses a very high concentration of this amino acid. Markus et al. found that people who had a poor ability to cope with stress were given this type of dairy protein; they saw marked increases in serotonin and cortisol levels. Subjects also reported a much better mood state when placed under high stress situations.

            This is important to note because previous reports found that diets that were high in carbohydrate and lower in protein resulted in a greater increase in serotonin19, 20. However, these reports did not use a whey based protein. As stated in the mode of action, whey floods the system with amino acids in a very short time. The research on serotonin suggests that a 25%-50% 12, 19, 20 increase in Tryptophan levels is required to see an increase in serotonin. This is not possible with casein or whole food because of their slow digestion kinetics. Based on the results, the researchers concluded that even better results could be seen if the whey protein was of better quality and possessed even higher tryptophan levels (i.e. an isolated vs. a concentrated protein). One draw back of this study is that results were seen in people who had high stress levels. Although this may seem good, one would have to question if it were the supplement or a placebo effect of some kind. If it were the cause of the stress reduction, even people with low stress levels should see some reductions.