When most people think about whey protein, they think about building muscle. Protein shakes at the gym. Meal replacement drinks in lieu of real food.
The six-meal-and-three-snack-a-day bro who keeps a whey shake on his bedside table to maintain those 2 AM gains.
The up-at-dawn-to-beat-rush-hour woman who drinks a shake in the car in lieu of a pastry.
As most people see it, whey protein’s just for people who want more protein in their diets, people who don’t have the time to cook, or people who hate to cook and also need more protein. It’s for weight lifters and athletes. It’s a “poor replacement” for real food. It’s a compromise when life happens. If you can cook and eat real food regularly, the popular story goes, you don’t need whey protein. Just eat real food—right?
But there’s actually much more to whey than just building muscle.
What is Whey Protein?
Whey is a protein-packed byproduct of cheese production. It’s that pseudo-clear liquid remaining after milk has been curdled and strained. Cheese makers used to toss it aside as waste material, turn it into ricotta cheese, or feed it to livestock until food scientists started to understand its value as a protein supplement for humans.
Today, we know that whey protein is the single best supplementary source of complete essential amino acids. It contains all the essential amino acids we need to promote muscle protein synthesis and muscle growth. is far more than a byproduct of cheese-making. It’s also more than just a single protein. Instead, it houses an impressive array of components with a wide variety of biological effects: beta-lactoglobulin, alpha-lactalbumin, lactoferrin, and immunoglobulins.
Promotes glutathione synthesis and reduces allergic disease incidence.
Improves retinol/vitamin A absorption and uptake.1
Those are just a few of the components found in that undigested whey powder sitting in your pantry. Once the whey hits your GI tract, it forms even more bioactive peptides with their own unique effects. Some improve blood lipids, lower blood pressure, or act as opioid receptor agonists (if you’ve ever seen a milk-drunk baby bliss out after nursing, his opioid receptors are likely being severely agonized by bioactive whey peptides). Others induce satiety and improve metabolic health biomarkers.
Is Whey Protein Good for You?
Yes. Whey protein can help you gain muscle and improve many health conditions, like obesity, diabetes, fatty liver, and more.
Muscle: Regardless of your age, gender, or when you take it, combining whey protein with strength training consistently produces better results and larger muscles.5 It isn’t necessary to gain muscle and build strength if you’re eating enough protein through food, but whey protein certainly helps you add high-quality animal protein to your diet.
Obesity: Whey tends to reduce fasting insulin levels in the obese and overweight (but not healthy prepubertal boys, who could use the growth promotion), increase satiety, reduce food intake, and improve resting energy expenditure.678910 If you’re trying to lose weight or prevent obesity, increasing the amount of energy you burn at rest and decreasing the amount you consume—by manipulation of satiety and fat-burning hormones—are indispensable effects.
Diabetes: Eaten before a meal, whey reduces the glucose spike from the subsequent meal in non-diabetics and type 2 diabetics alike. It achieves this by “spiking” insulin, but transiently; the insulin area under the curve improves even as the immediate insulin response increases.111213 Plus, as seen above, fasting insulin tends to lower in people consuming whey protein.
Fatty liver: In obese women, a whey supplement reduces liver fat (and as a nice side effect increases lean mass a bit).14 Fatty liver patients also benefit from whey, enjoying improvements in glutathione status, liver steatosis, and antioxidant capacity.15 Rats who supplement with whey see reduced fat synthesis in the liver and increased fatty acid oxidation in the skeletal muscle.16
Stress: In “high-stress” subjects, a whey protein shake improved cognitive function and performance by increasing serotonin levels.17 The same shake had no effect on “low-stress” subjects. And dietary whey also lowers oxidative brain stress, at least in mice.18
Cancer: Both the lactoferrin found in whey and the glutathione synthesis whey promotes may have anti-cancer effects. Lactoferrin shows potential to prevent cancer that has yet to occur and induce cell death in existing cancer cells.1920 In a recent human study, oral lactoferrin suppressed the formation of colonic polyps.21 And in animal cancer studies and human cancer case studies, whey protein has been shown to increase glutathione (“foremost among the cellular protective mechanisms”) and have anti-tumor effects.22 Whey protein can also help cancer patients stave off muscle loss and maintain strength.23
HIV: HIV is characterized by a drastic reduction in glutathione levels. And even if whey doesn’t always increase body weight in HIV patients, it does improve CD4 (a type of white blood cell) count, lower the number of co-infections, and persistently increase glutathione status.242526
Heart disease: A review of the effect of whey on major cardiometabolic risk factors found that whey protein improves the lipid profile, reduces hypertension, improves vascular function, and increases insulin sensitivity and glucose tolerance.27 Whey peptides that form during digestion actually act as ACE-inhibitors, reducing blood pressure similarly to pharmaceuticals without the side effects.28
Sarcopenia: Muscle wasting, whether cancer-related or a product of age and inactivity, is a huge threat to one’s health and happiness. Studies show that whey protein is the most effective protein supplement for countering sarcopenia, especially compared to soy.2930 A buddy of mine can attest to this; a couple months back, his grandmother hadn’t eaten for a few days, was suffering from diarrhea, mental confusion, and basically appeared to be on her deathbed. He started making her whey protein-based milk shakes and the recovery was rapid. She grew alert, active, and regained her appetite and control of her bowels. She’s not out of the woods, but at least her remaining days will be much better than the direction they were heading.
Gastrointestinal disorders: Contrary to concerns about dairy and gut health, whey can actually improve gut health and gut barrier function, even in patients with gastrointestinal disorders. In human Crohn’s disease patients, a whey protein supplement reduces leaky gut.31 In rodent models of inflammatory bowel disease, whey protein reduce gut inflammation and restore mucin (the stuff used to build up the gut barrier) synthesis.32
Is whey protein dairy?
Whey comes from milk products, so yes, whey protein is dairy. it’s a major bioactive component of dairy. And, as with other forms of dairy, we have to consider the issue of dairy intolerances and allergies. Dairy just doesn’t work for everyone, whether it’s the lactose or the proteins.
Lactose intolerant. Lactose intolerance is a sensitivity to a form of sugar in dairy products.
Casein sensitive. Casein sensitivity is an intolerance of one of the proteins in dairy products
Luckily, most people can tolerate whey without issue. You’re far more likely to be allergic, sensitive, or intolerant to lactose or casein than to whey. And whey may even be downright anti-allergenic, as whey-based formulas have shown efficacy in the prevention of allergic diseases like asthma and eczema in susceptible children and infants.3334
The exception to this may lie in geography and ethnicity: In East Asian countries like Taiwan, whey sensitivity appears to be more common than casein sensitivity. In western regions like the United States and Europe, casein intolerance is far more common than whey.35 However, that’s just one study in people with atopic dermatitis. It might not apply to everyone.
I’ve found that most people with “dairy intolerance” can usually handle whey protein isolate, which has little to no lactose and almost zero casein.
Why eat whey protein when we could just eat yogurt, cheese, or drink milk?
In most mammalian milk, casein protein predominates and whey is a minor fraction of the total protein content. Cow, goat, horse, sheep—very high in casein, low in whey. But in human breastmilk, this ratio flips. As much as 80% of the total protein in human breastmilk is whey protein, where it plays important roles in immune system regulation and programming, cellular growth and differentiation, and overall physical and mental development. Infants raised on formula higher in casein end up with less lean mass and more fat mass than infants raised on formula higher in whey (and closer to the composition of breastmilk).36
You could make the argument that whey protein is one of the most ancestrally consistent dairy foods a person can eat.
Overall, whey protein is much more than just a protein supplement. It builds muscle, improves glucose control, regulates immune function, lowers stress, and confers a ton of beneficial effects on people who consume it. Real food is the foundation for a healthy diet. But whey protein is much more than a muscle-builder and meal replacer. I’d argue that it deserves a spot on the “supplemental foods” list alongside egg yolks, liver, fatty fish, and all the other foods that are powerful and vital in small doses.
I feel comfortable recommending its use for almost everyone, given that it’s one of the best-studied and oldest dietary supplements around.
Let’s hear from you guys. Do you take whey? If so, what kind and why? How have you benefited?
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.