Little Miss Muffet
Sat on a tuffet,
Eating her curds and whey…
The popular “Little Miss Muffet” nursery rhyme, which first appeared in print in the early 19th century, demonstrates how long whey protein has been part of a healthy diet. Indeed, whey protein is one of the most well-known, ubiquitous dietary supplements.
How can something seemingly so healthy possibly be harmful? Could whey protein be bad for you?
What is Whey Protein?
The two major components of (cow’s) milk protein are whey, which is rapidly digested, and casein (also known as “curds”), which is digested much more slowly. Whey makes up 20% of the proteins in milk and is the liquid portion of milk. It is separated from the curd, which comprises the remaining 80% during the cheese-making process. Whey contains 5 major proteins (including β-lactoglobulin, α-lactalbumin, and glycomacropeptide) and hundreds of low-abundance proteins (including lactoferrin).
When it comes to protein quality, the protein digestibility amino acid score (PDCAAS) and digestible indispensable amino acid score (DIAAS) are the two most widely accepted measures. Regardless of which scale you refer to, whey is often crowned king, setting the bar with the highest scores.
While particularly popular among athletes and bodybuilders, whey protein is an excellent source of protein for individuals of all ages, as it can provide tremendous support to anyone who values a healthy lifestyle.
Is Whey Protein Good For You?
Whey Protein Benefits
1. Muscle Recovery, Growth, and Strength
Two primary factors governing muscle recovery and growth are muscle protein synthesis (MPS), or the rate the body rebuilds muscle, and muscle protein breakdown (MPB), or the rate the body breaks down muscle. Whey protein is an abundant source of essential amino acids (particularly leucine), the “building blocks” of muscle. It’s rapidly digested, making it an excellent protein source for increasing MPS and regulating muscle mass.
When whey protein is consumed after resistance training, there is a synergistic effect on MPS along with a complete abolishment of MPB, which leads to muscle gain over time. A good rule of thumb is to consume 20 – 25 grams of whey protein within a couple hours before and/or after exercise.
2. Appetite Control
Consumption of whey protein can have a powerful effect on appetite, which can help control cravings and food intake. While it’s commonly accepted that protein in general increases satiety, some research suggests whey may have specific advantages. For instance, whey protein has been shown to decrease hunger to a greater extent than other sources of protein (such as soy, tuna, turkey, and eggs). Whey (perhaps through glycomacropeptide) consumption leads to an increase in hormones like GLP-1, GIP, and CCK, which suppress appetite and promote satiety, and a decrease in levels of the “hunger hormone” ghrelin.
3. Body Composition and Weight Management
In general, high-protein, reduced-calorie diets promote healthy weight management, and compared to normal-protein diets, they tend to accelerate fat loss, help maintain calorie-burning lean muscle mass, and prevent weight regain.
While most people focus on weight loss, fat loss combined with muscle gain/maintenance (improved body composition) is ideal, as it is key to achieving a lean, toned appearance and promoting long-term weight maintenance. Because muscle is metabolically active, a loss of muscle mass—from dieting or being sedentary—is a major risk factor for weight regain. This is not only because of the impact on metabolic rate, but also because the body compensates by driving overeating—a phenomenon referred to as “collateral fattening.”
4. Healthy Aging
As we get older, we tend to experience a slow and inevitable decline in muscle mass along with significant reductions in strength. This can have tremendous consequences, adversely affecting mobility and physical function, leading to a greater incidence of falls, contributing to several age-related health conditions, reducing independence, and overall decreasing quality of life.
Certainly, a sedentary lifestyle (“use it or lose it”) plays a substantial role. Yet inadequate consumption of protein can accelerate age-related muscle loss. Conversely, regular resistance training combined with adequate protein intake can help limit muscle loss and promote healthy aging.
5. Immune Support
Compared to other protein sources, whey protein is unique in its ability to optimize immune function. On one hand, whey protein can boost levels of glutathione, commonly referred to as the body’s “master antioxidant.” Glutathione supports immunity by replenishing the body’s primary defense system. It is also a natural detoxifier, helping to eliminate potentially harmful toxins.
Whey is also rich in the amino acid glutamine, which is required for optimal immune system function. Whey protein also contains immunoglobulins and lactoferrin, which are established immune-enhancing constituents.
6. Carbohydrate Management
Numerous studies have shown that high-protein diets lead to significant improvements in glycemic (the effect of food on blood sugar levels) control and metabolic function in as little as 5 weeks. In particular, the addition of whey protein to a carbohydrate-containing meal has been shown to significantly reduce the glycemic response. This acute improvement in metabolic function seems to be related to whey’s influence on insulin (more on that below).
7. Cardiovascular Health
Generally speaking, research suggests that milk consumption and intake of dairy proteins are associated with reduced blood pressure. Of course, maintaining healthy blood pressure is imperative for cardiovascular health. β-Lactoglobulin, the most abundant protein in whey, inhibits angiotensin-I-converting enzyme (ACE), which in turn has a beneficial effect on blood pressure. Whey protein may also support healthy levels of blood cholesterol and triglycerides, suggesting additional heart health benefits.
The Drawbacks of Whey Protein?
With all those benefits in mind, how could there possibly be a “dark side” to whey protein? That’s a good question; let’s explore!
1. Digestion and Absorption I
As mentioned above, whey is considered a “fast” digesting protein. The maximum absorption rate has been shown to be about 8 – 10 grams per hour. Due to its rapid transit time through the small intestine, which is reported to be about 90 minutes, absorption of whey may be limited to 15 grams, with anything above that being potentially “wasted.”
Editor’s Note: 9 Proteins That Expand Your Waist
2. Digestion and Absorption II
A fast-digesting protein like whey is indeed desirable at certain times, such as before and after exercise. However, there may be times (such as before bed) when a slow-digesting protein like casein may be optimal. Additionally, a combination of fast- and slow-digesting proteins may be ideal during the day when a more consistent, sustained release of amino acids would be preferred.
Believe it or not, whey protein has been shown to be more insulinogenic (that is, stimulates the production of insulin) than white bread. Because of the connection between poor insulin sensitivity and obesity, many view this as bad.
Indeed, high levels of insulin as a result of poor carbohydrate management seem to be a serious health issue. However, this logic applied to whey is faulty. In fact, the insulinotropic effects of whey protein may have important benefits in improving carbohydrate tolerance and metabolic function.
4. Artificial Sweeteners
Besides intake of dairy products, whey protein is most commonly consumed as a dietary supplement. Along these lines, it’s important to review product labels to verify that the whey protein does not contain ingredients that may be potentially hazardous to your health.
One striking example is artificial sweeteners, which may have negative effects on gut health, metabolic function, cognitive function, weight management, and redox status (oxidative stress).
The processing methods for whey can have a significant impact on the overall quality, digestibility, and bioavailability of the proteins. Many whey proteins are manufactured using high-heat and chemical processing, which can damage the delicate proteins and selectively reduce the beneficial bioactives, such as lactoferrin and immunoglobulins, which provide numerous health benefits. A better idea is to choose a whey protein that is carefully processed at cold temperatures.
6. Hormones and Antibiotics
Bovine somatotropin (BST) is a hormone naturally produced in the brains of dairy cows. A genetically engineered recombinant version of BST (rBST or rBGH) is injected into some cows to boost milk production. Unfortunately, cows treated with rBST are at a greater risk for infection, reduced fertility, and disability. The increased risk for infection leads to increased use of antibiotics, which can contaminate milk and lead to the development of antibiotic-resistant bacteria in humans. Make sure you find a whey protein free from rBST and rBGH.
7. Animal Cruelty
Remember, whey comes from milk, which comes from cows. While it’s beyond the scope of this article to talk morals and ethics of animal welfare, my personal recommendation is to only choose whey protein that comes from happy, healthy, humanely treated cows.
So, is Whey Protein Good For You?
Whey protein is lauded for its benefits—and rightly so. While it’s a stretch to say everyone needs to include whey protein, it’s perhaps more absurd to say whey protein is “bad” for you. However, not all whey protein supplements are the same, and there are important considerations when choosing a whey supplement and how you use it as part of an overall healthy lifestyle.
The Problem with Most Protein Supplements: