Whey Protein supplement health benefit and side effects - soy versus whey, which one is better? by Ray Sahelian, M.D.
March 15 2019

Whey is a protein found in milk and has been promoted as having a number of health benefits. Milk has two proteins: Casein (approximately 80%) and whey protein (approximately 20%). Whey protein is used as a supplement in those interested in body building. A high protein intake can help many people restrict food intake since protein has satiating effects. Whey protein is used by those interested in exercise performance and enhancement. See amino acid list and articles relating to individual amino acids.

Availability as a supplement in health food stores
Whey protein is often processed to become either a concentrate, an isolate, or a hydrolysate. They are sold in several forms, including powder of shakes. Each person has a different optimum dosage depending on age, size, activity level, athlete or non athlete, etc.

Concentrates have a lower level of fat and cholesterol but, in general, have higher levels of bioactive compounds, and carbohydrates in the form of lactose — they are 309%–90% protein by weight.

Isolates are processed to remove the fat, and lactose, but are usually lower in bioactivated compounds as well — they are often more than 90% protein by weight.

Hydrolysates are whey proteins that are partially hydrolyzed for easier metabolizing. They may be less allergenic.

Whey protein has been touted as potentially being helpful in a number of medical conditions as listed in the studies below. Whey protein may be helpful in blood sugar control. Whey protein could also improve muscle mass and be used together with creatine for bodybuilding. Whey has antioxidant, antihypertensive, antitumor, hypolipidemic, antiviral, and antibacterial properties. The amino acid cysteine in whey converts into glutathione, a strong intracellular antioxidant. Whey has been tested as a treatment or supportive agent for cancer, HIV, hepatitis B, cardiovascular disease, and osteoporosis. It may also be helpful in immune function disorders.

Q. If a person is considered intolerant of lactalbumin, can they still drink whey protein isolate?
   A. Whey protein isolate does have lactalbumin, one of the proteins of milk (casein 3%, lactalbumin 0.5%, lactoglobulin 0.25%). Not precipitated from acid solution as is casein, whey contains lactalbumin and lactoglobulin, which are precipitated by heat and can be used to make whey.

Whey Protein Supplement and Muscle Mass
The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training.
J Strength Cond Res. 2006. Center for Exercise, Nutrition and Preventive Health Research, Department of Health, Baylor University, Waco, TX, USA.
The purpose of this study was to examine the effects of whey protein supplementation on body composition, muscular strength, muscular endurance, and anaerobic capacity during 10 weeks of resistance training. In this study, the combination of whey and casein protein promoted the greatest increases in fat-free mass after 10 weeks of heavy resistance training. Athletes, coaches, and nutritionists can use these findings to increase fat-free mass and to improve body composition during resistance training.

For people with type 2 diabetes, adding whey to high-carbohydrate meals stimulates insulin release and reduces spikes in blood glucose levels after meals.

Med Sci Sports Exerc. Feb 5 2014. Whey Protein Improves Exercise Performance and Biochemical Profiles in Trained Mice.

Immune system
Whey has a number of compounds that have an influence on the immune system. These include, including lactoferrin, beta-lactoglobulin, alpha-lactalbumin, glycomacropeptide, and immunoglobulins.

Rhuematoid arthritis
Q. Long time fan! you have great info, which is why I'm reaching out to you. I have rheumatoid arthritis, to which I'm on a biologic, Humira, switching to Enbrel soon. I've been a life long bodybuilder/weightlifter and trying to find data, good/bad on whey protein an its interaction with RA. I'm an critical care RN, almost NP so I have a good medical background but little data on the subject.
   A. As of 2019 I have not seen studies regarding the role of whey protein in RA.

Use by teenagers
Hi, i'm sixteen years old, and i'm into weight-training. Only recently, I was considering taking whey protein, in the form of powder shake, but I am a bit concerned over any possible health risks or side-affects, with special consideration to my age. I've also heard that it can damage the liver, but not really sure if it's true. I would really appreciate it if you could help me out here, by giving any advice or anything at all that may be useful.
   As long as it is used in small amounts with frequents breaks, it should be safe to use.

Soy protein versus whey protein supplement
Soy protein and whey protein are equally beneficial in promoting muscle protein synthesis. Researchers at Indiana University's School of Medicine in Evansville compared the early response of skeletal muscle protein synthesis and translation initiation following the ingestion of different protein sources after endurance exercise in rats. The animals were subjected to 120 minutes of treadmill exercise and then fed a carbohydrate-only, carbohydrate and whey protein, or carbohydrate and soy protein meal. Soy and whey proteins were equally effective at promoting general protein synthesis in the rats' skeletal muscle, and markedly inferior synthesis was associated with the carbohydrate-only meal.

Whey Protein Research
Whey protein supplementation and resistance training to enhance muscle growth in young and older adults.
Asia Pac J Clin Nutr. 2005.
A major cause of age-related disabilities is progressive loss of skeletal muscle mass (sarcopenia). Protein ingestion and strength exercise have both been reported to increase protein synthesis through signalling cascades resulting in ribosomal activation via activating key components of the translation initiation complex. Skeletal muscle biopsy samples were taken from the thigh (vastus lateralis) from young and older men, after a single bout of exercise (untrained) and again following 12 weeks supervised resistance training with repeated whey protein isolate (25 g) or placebo supplementation. Whey protein isolate supplementation significantly increased eccentric strength after training (25% greater than placebo) in young, but not in older adults. Older participants consuming the whey protein isolate supplement demonstrated greater phosphorylation of the translational factor p70-S6K1 after 12 weeks training (2.9 fold increase, when compared to the placebo group. This effect was not observed in the younger groups. Following exercise training older adults consuming whey protein isolate resulted in a 17.3 fold increase in Pax7 gene (marker of satellite cell activation) compared to a 2.6 fold increase in the placebo group post training. Only a small increase in Pax7 gene expression was observed in the young groups, with a 2.6 fold increase in the whey protein isolate group and 1.9 fold increase in the placebo group. Conclusions - These findings provide molecular evidence of enhanced activation of translation initiation with combining whey protein isolate intake and chronic resistance training in older participants. There were no beneficial actions of whey protein isolate on p70-S6K1 activation in young male subjects.

Effect of whey on blood glucose and insulin responses to composite breakfast and lunch meals in type 2 diabetic subjects
American Journal of Clinical Nutrition, July 2005
The aim of this study was to evaluate whether supplementation of meals with a high glycemic index (GI) with whey proteins may increase insulin secretion and improve blood glucose control in type 2 diabetic subjects. Results: The insulin responses were higher after both breakfast (31%) and lunch (57%) when whey was included in the meal than when whey was not included. After lunch, the blood glucose response was significantly reduced after whey ingestion. Postprandial GIP responses were higher after whey ingestion, whereas no differences were found in GLP-1 between the reference and test meals. Conclusions: The addition of whey protein to meals with rapidly digested and absorbed carbohydrates stimulates insulin release and reduces postprandial blood glucose excursion after a lunch meal consisting of mashed potatoes and meatballs in type 2 diabetic subjects.

Dietary whey protein modulates liver glycogen level and glycoregulatory enzyme activities in exercise-trained rats.
Exp Biol Med (Maywood). 2005 Jan.
This study compared the effects of dietary whey protein with dietary casein or soy protein on glycogen storage and glycoregulatory enzyme activities in the liver of sedentary and exercise-trained rats. Male Sprague-Dawley rats (ca. 130 g) were divided into one sedentary and three exercise-trained groups, with eight animals in each group. Casein was provided as the source of dietary protein in the sedentary group while the exercise-trained groups were fed casein, whey, or soy protein. Rats in the exercise-trained groups ran for 30 mins/day, 4 days/week on a motor-driven treadmill. In the exercise-trained rats, animals fed whey protein had higher liver glycogen content than animals in the other two diet groups. Our results demonstrate that the whey protein diet in exercise-trained rats results in significantly higher levels of liver glycogen, because of the combined effects of regulation of rate limiting glycolytic and gluconeogenic enzyme activities and activation of glycogenesis from alanine via alanine amino-transferase.

Soy versus whey protein bars: Effects on exercise training impact on lean body mass and antioxidant status.
Nutr J. 2004 December.
Although soy protein may have many health benefits derived from its associated antioxidants, many male exercisers avoid soy protein. This is due partly to a popular, but untested notion that in males, soy is inferior to whey in promoting muscle weight gain. This study provided a direct comparison between a soy product and a whey product.  Lean body mass gain was examined in males from a university weight training class given daily servings of micronutrient-fortified protein bars containing soy or whey protein (33 g protein/day, 9 weeks, n = 9 for each protein treatment group). Training used workouts with fairly low repetition numbers per set. A control group from the class did the training, but did not consume either type protein bar. Both the soy and whey treatment groups showed a gain in lean body mass, but the training-only group did not. The whey and training only groups, but not the soy group, showed a potentially deleterious post-training effect on two antioxidant-related related parameters. Soy and whey protein bar products both promoted exercise training-induced lean body mass gain, but the soy had the added benefit of preserving two aspects of antioxidant function.

Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise.
Med Sci Sports Exerc. 2004. Tipton KD, Elliott TA, Cree MG, Wolf SE, Sanford AP, Wolfe RR. Metabolism Unit, Shriners Hospitals for Children and Department of Surgery, The University of Texas Medical Branch, Galveston, TX
Determination of the anabolic response to exercise and nutrition is important for individuals who may benefit from increased muscle mass. Intake of free amino acids after resistance exercise stimulates net muscle protein synthesis. The response of muscle protein balance to intact protein ingestion after exercise has not been studied. This study was designed to examine the acute response of muscle protein balance to ingestion of two different intact proteins after resistance exercise. Healthy volunteers were randomly assigned to one of three groups. Each group consumed one of three drinks: placebo (PL; N = 7), 20 g of casein (CS; N = 7), or whey proteins (WH; N = 9). Volunteers consumed the drink 1 h after the conclusion of a leg extension exercise bout. Acute ingestion of both whey protein and casein after exercise resulted in similar increases in muscle protein net balance, resulting in net muscle protein synthesis despite different patterns of blood amino acid responses.

Improved glutathione status in young adult patients with cystic fibrosis supplemented with whey protein.
J Cystic Fibrosis. 2003.
The lung disease of cystic fibrosis is associated with a chronic inflammatory reaction and an over abundance of oxidants relative to antioxidants. Glutathione functions as a major frontline defense against the build-up of oxidants in the lung. This increased demand for glutathione (GSH) in cystic fibrosis may be limiting if nutritional status is compromised. We sought to increase glutathione levels in stable patients with cystic fibrosis by supplementation with a whey-based protein.  Twenty-one patients who were in stable condition were randomly assigned to take a whey protein isolate (Immunocal, 10 g twice a day) or casein placebo for 3 months. Peripheral lymphocyte GSH was used as a marker of lung GSH. Values were compared with nutritional status and lung parameters. At baseline there were no significant differences in age, height, weight, percent ideal body weight or percent body fat. Lymphocyte GSH was similar in the two groups. After supplementation, we observed a 46.6% increase from baseline in the lymphocyte GSH levels in the supplemented group. No other changes were observed. The results show that dietary supplementation with a whey-based product can increase glutathione levels in cystic fibrosis. This nutritional approach may be useful in maintaining optimal levels of GSH and counteract the deleterious effects of oxidative stress in the lung in cystic fibrosis.

Side effects of whey protein
Those who have an allergy to milk protein could potentially have an allergy to whey protein. For instance, children could have dermatitis or eczema. Excessive amounts of whey protein could place stress on the liver and kidneys. You can reduce or avoid the whey protein side effects by limiting your intake or a whey protein supplement.

Combining with other supplements
Fish oil and krill oil supplement capsules can be safely taken up to five a day.

Email questions
If an infant is allergic to cow milk, which of the two soy protein or whey protein be okay to use?
   Either soy protein or an extensively hydrolyzed whey protein would be acceptable depending on how the infant is tolerating either formula. Perhaps it is a good idea to use both.

Q. I have seen where you've spoken of the benefits of whey and soy proteins, but what can you say of casein protein? I gather it is a slow-absorbing protein, which it is said is ideal for "slow-release" availability of amino acids over a period of time, say overnight, and there are many bodybuilding powders with this "slow-release technology" that employ casein protein for this very reason. Other than that, I gather casein is a fairly good, complete source of protein -I know it's harder to mix out though! So I was just wondering what you say of casein's bodybuilding benefits, and of its general health benefits? How does it compare to whey for example, other than being more slowly absorbed (and less easily mixed)?
   A. I really don't know much about casein protein and how different it would be than whey protein or soy in terms of its influence on bodybuilding. I am not an expert in athletic enhancement. However, my impression would be that it is best to use various different proteins as opposed to exclusively just one. The body likes to have a variety of exposures, and sometimes repels or dislikes being given a high amount of the same thing all the time. So, you could consider mixing different protein powders.

Q. What do you think of meal replacement with whey protein drink ?
  A. Please see this web page meal replacement for information.

I have a friend who is interested in a nutrition product that has whey protein in it, instead of meat proteins. Since she is "allergic to milk," i.e. lactose intolerant, can she consume whey protein? In your article on natural options for ulcer relief, you list there are many herbs, nutrients, and plant products that have been found to play a role in protecting or helping to heal stomach and peptic ulcers, including whey. However, at the end of the whey article, there is a comment that some who have an allergy to milk protein could potentially have an allergy to whey protein. So, nutritionally, I? confused. Is whey ok for someone who is lactose intolerant? Can you elaborate?
   A person can have lactose intolerance, meaning difficulty in digesting lactose, a sugar. A person can also be allergic to casein, one of the proteins in milk. Whey is another protein found in milk. Lactose, the sugar, is different than casein or whey, which are proteins. A whey protein supplement, depending on the product and how it is isolated, probably has some lactose, but not a large amount. Therefore ingesting a small amount of a whey protein supplement should not cause major problems unless a person is severely lactose intolerant. Purchase a whey protein product that says whey protein isolate as opposed to whey protein concentrate since whey protein concentrate would likely have a higher amount of lactose than whey protein isolate.

I am wondering if a low or no-lactose whey protein isolate product can still cause excess mucus production and if soy protein is better in this regard? I am currently trying to isolate what may be causing this in my diet, so wondering how you feel about whey versus soy protein in general for dietary purposes and also with regards to mucus production.
   I think casein in milk may be more of a problem than whey protein in terms of mucus production but I am not fully certain of this. I prefer to alternate different protein powders rather than using the same one all the time. Another option is fish protein powder.

I read with interest your Q & A on glutathione. You refer to a clinical study on cystic fibrosis patients using a whey protein to increase intracellular glutathione. I believe the whey protein used in that study is known as Immunocal and is available as a supplement. There are several completed clinical studies which have been peer reviewed and published in medical journals on Immunocal which has been shown to raise intracellular glutathione levels. Since you show a keen interest in finding a supplement that has been scientifically documented to raise glutathione., Immunocal is your answer.
   It does appear that there have been several studies published with Immunocal whey protein supplement.

I take approximately 40 grams of MRM Whey Protein (no artificial flavors or sweeteners) every morning with unsweetened Almond Milk. However, I only have one kidney (one is hypoplastic). Is this amount of Protein dangerous to my one very healthy kidney? For a condition (Protein Urea due to one Kidney) I take 10mg of Lisinopril daily. According to my Nephrologist, this amount shouldn’t cause any excess protein in my urine but would welcome your thoughts? Can Whey Protein cause excess mucus (clear) in the nose Only, not throat)? I have to clear my nose several (maybe 20x’s or more a day, more so during my workouts).
    I have not seen research regarding the role of whey protein supplement use and nose congestion, but one way to tell is to stop the product for a couple of weeks to see if the condition improves. Since I don't know your full laboratory history of test results and have not done a medical exam on you, I can't comment on whether the amount of the supplement you are taking is excessive and don't wish to say anything that conflicts with the advice of your doctor who knows your medical history much better than I do.

I am a prediabetic, and much interested in nutrition and supplements to improve my condition. Recently I tested the effect of whey on blood glucose, and found that 1/2 to 1 oz of pure whey concentrate or isolate (no sugar added) raised blood glucose from 120s to 150s.This is not what I expected from an essentially pure protein, and seems to run counter to findings that whey lowers glycemic response of high carbohydrate meals. Do you have an explanation for my results? I would like to consume whey for its benefits, but fear its tendency to raise blood sugar to undesirable levels.
   We are not sure why this is happening to you.