Whey Protein pros and cons

In this Article (Index)

• What is a Protein?
• The importance of Protein
• Recommended Dietary Allowances for Protein
• Protein sources and supplementation
• Whey Protein
• Whey Varieties
• Health Claims regarding Whey Protein
• High-protein intake
• Older Adults
• Protein Intake for healthy exercising adults
• Risks and Side Effects of a High-Protein diet
• Risk of kidney stones
• Risk of Chronic kidney disease (CKD)
• The Source of the Protein is important
• Liver risks
• Protein Quality
• Conclusions

What is a Protein?

A protein is an essential nutrient (like fats and carbohydrates); proteins are organic molecules made up of chains consisting of different amino acids (these in turn are small molecules that contain carboxylic and amino functional groups).

There are thousands of different proteins and they are an important component of your body and its organs.

The body synthesizes its own proteins using the ones it ingests when you eat. Your body breaks down the proteins in food into their component amino acid molecules, and then reassembles these amino acids into new proteins. It does so by joining them up in sequences set down by your DNA.

There are some 20 different types of amino acids of which eight are essential in your diet because your body can't make them. You must get them from what you eat.

There are animal proteins and plant-based proteins. Some foods contain more protein than others. Milk, beef, fish, seafood, legumes, cereals are all good sources of protein.

It is important (especially for those following vegan or vegetarian diets) to eat a diet with the correct "mix" of plant proteins, that contain these essential amino acids.

The importance of Protein

Aminoacides are used by the cells to produce metabolites that have are critical for life, making protein undernutrition a life-threatening condition.

Lack of protein can cause anemia, physical weakness, stunted growth, edema, cardiovascular and neurological issues, and lower the body's defenses impairing its immunity. (8)

To ensure a correct intake of protein, recommended dietary allowances have been defined.

Recommended Dietary Allowances for Protein

The Recommended Dietary Allowance of protein in the U.S. for a healthy adult with minimal physical activity was set at 0.8 g protein per kg body weight per day. (10)

This translates as 0.28 oz per 22 lb of body weight per day.
A person weighing 175 lb (80 kg) would need to ingest 175 * 0.28 &frasl ;22 = 2.2 oz (64 g) of protein daily.

The National Academies of Sciences didn't set any upper limits.

there was insufficient data to provide dose-response relationships to establish a Tolerable Upper Intake Level (UL) for total protein or for any of the amino acids. However, the absence of a UL means that caution is warranted in using any single amino acid at levels significantly above that normally found in food. National Academies of Sciences (10)

However individuals engaging in moderate to intense physical activity or those keen on building physical strength and muscle will consume more than 0.8 g per kg per day; and there are also special groups who may need additional protein intake. We will look into this and the risk-benefits in another section.

Protein sources and supplementation

A healthy balanced diet should cover the RDA of 0.8 g per kg per day needed by a healthy adult.

• 8 g - in one cup of non-fat milk.
• 6 g - in one large hard boiled egg.
• 4 g - in one half cup of white rice.
• 6 g - in cottage cheese (1.8 oz - 50 g).
• 4 g - in one medium potato (7 oz - 200 g)
• 28 g - in ground beef (3.5 oz - 100 g).
• 3 g - in a regular lettuce (2 oz), tomato (one medium), onion (1/2) salad.
• 5 g - in one half cup of rolled oats.

These foods would cover the RDA of a 175 lb (80 kg) adult.
Dairy, eggs and animal sources are protein dense. But legumes, vegetables, fruit, and grain also provide protein with the added advantage of fiber and plant-based biocompounds.

But those intent on building muscle, who would ingest up to two and a half times this RDA and therefore, they'd have to eat a larger amount of food to be able to cover their needs.

This isn't practical, and that is why supplements were developed: they offer a concentrated protein without the other elements (carbs and fats) found in food. Adding 40 g of protein on top of the RDA using a 90% grade of whey protein means ingesting the equivalent of 3 tablespoons of protein powder into a couple of glasses of water or milk.

But, once again, is it safe to ingest more protein than the recommended dietary allowance?

Whey Protein

Milk contains two proteins, of which 80% is casein and the remaining 20% is whey.

Whey Protein is sold as a supplement. It a mixture of proteins obtained from whey, a liquid by-product obtained from milk during the production of cheese. Therefore, it is an animal protein.

During cheese manufacture, milk is coagulated by adding an acid or rennet, and forms curds, a semi-solid product that is then strained and made into cheese. Curds contain fats, carbohydrates and mostly casein, a milk protein.
The residue is a pale yellowish liquid that contains roughly 93.2% water, and about 5% lactose, 0.9% proteins, and around 0.9% fat, plus minerals and vitamins.

Therefore you obtain less than 1 gram of protein per 100 g of liquid whey.
This liquid whey protein is a mixture of roughly 48-58% β-lactoglobulin, 13-19% α-lactalbumin (this protein is a strong source of branched amino acids, cysteine, and tryptophan residues) and, 12-20% serum albumin (a type of globular protein), 12-20% caseinomacropeptide, also called glycomacropeptide also makes up the third largest component but is not a protein it is a glycosylated peptide (peptide = short chain of aminoacids; glycosylated = a sugar has been attached to a peptide chain). The minor components are immunoglobulins (IGs or antibodies)and several minor whey proteins.They are all water soluble. (6)

The whey is then pasteurized to eliminate unwanted microorganisms and processed to extract the protein.
It is then concentrated, eliminating the other components and converted into powder in a spray dryer.

Whey Varieties

There are four types of whey in the market:

• Whey Protein Concentrates (WPC). The whey is dried removing most of the liquid, and the final product contains between 20% and 80% protein, fats and lactose (milk sugar). The concentration is done usingr microporous membranes that allow small molecules like lactose, mineral salts, and water to pass through, while the larger ones such as proteins, fat globules and suspended solids, are retained and concentrated.
• Whey Protein Isolates (WPI). The lactose and residual fat is removed leaving a product that is roughly 90% protein, 5% water and 5% ash.
• Whey Protein Hydrolysates (WPH). This whey is hydrolized, meaning that the long chain proteins have been cut up into smaller peptides using enzymes. This makes it easier for the body to absorb them. They are used in hypoallergenic baby milk formulas as they tend to be less allergenic than longer protein chains.
• Native whey. The protein is extracted directly from the milk using an ultrafiltration process at a temperatures lower than 50°F (10°C), the protein is undenatured by this process and does not contain the glycomacropeptide, which forms during the curdling process.

Health Claims regarding Whey Protein

In 2010, the European Food Safety Authority found that the following health claims regarding whey protein were not backed by scientific proof: "whey protein and increase in satiety leading to a reduction in energy intake", "contribution to the maintenance or achievement of a normal bodyweight", "growth or maintenance of muscle mass", "increase in lean body mass during energy restriction and resistance training", "reduction of body fat mass during energy restriction and resistance training", "increase in muscle strength", "increase in endurance capacity during the subsequent exercise bout after strenuous exercise", "skeletal muscle tissue repair", and "faster recovery from muscle fatigue after exercise." (7)

High-protein intake: Some special cases

We have mentioned further up that the U.S. authorities defined an RDA for moderately active adults, and set it at 0.8 g per kg of body weight per day (0.8 g/kg/day). They didn't define values for exercising or physically active people, and didn't have data to define an upper limit for protein intake.

Older Adults

However, older people (65 years of age, or older) lose muscle mass at a rate of 0.5 to 1% per year from the age of 50 onwards, and a higher dietary protein intake could help slow down this muscle aging proces. This has been evaluated by differnt organizations (the International PROT-AGE Study Group (11) and the European Society for Clinical Nutrition and Metabolism (ESPEN) (12) who concluded that the RDA should be increased for these groups:(13)

1. For healthy older people: at least 1.0 to 1.2 g/kg/day
2. For older people who are malnourished or at risk of malnutrition because due to acute or chronic illness: 1.2 to 1.5 g/kg/day. With even higher intake for individuals with severe illness or injury.
3. Olderpeople should engage in daily physical activity or exercise (resistance training, aerobic exercise) for as long as possible.

The caution that older people with severe kidney disease are an exception to this rule; and may need to limit protein intake.

Protein Intake for healthy exercising adults

The International Society of Sports Nutrition (ISSN) has also noted that the RDA is not adequate for people who exercise. (9)

The ISSN says that the 0.8 g/kg/day covers the needs of roughly all healthy Americans aged 19 and older (97.5%) and is only appropriate for non-exercising individuals.

They argue that an active person requires more protein than a sedentary one, because (1) oxidation of proteins and aminoacids during exercise (your body burns them to provide energy for the workout) consumes them, and (2) exercise induced muscle damage requires protein to repair the tissue.
They propose protein intakes of 1.4 to 2.0 g/kg/day. for healthy exercising adults.
They say that if this protein intake is "part of a balanced, nutrient-dense diet...[it will not be] detrimental to kidney function or bone metabolism in healthy, active persons."

They add that protein or amino acid supplements are practical and stress that "appropriately timed protein intake is an important component of an overall exercise training program, essential for proper recovery, immune function, and the growth and maintenance of lean body mass."
The ISSN recommends the following intakes:

1. 1.0 to 1.6 g/kg/day for endurance exercise.
2. 1.6 to 2.0 g/kg/day for strength/power exercise.

Risks and Side Effects of a High-Protein diet

A high intake of protein may cause health problems. The ISSN states that healthy, exercising individuals ingesting protein above the RDA will not suffer from health problems, "individuals with mild renal insufficiency need to closely monitor their protein intake as observational data from epidemiological studies provide evidence that dietary protein intake may be related to the progression of renal disease." (9)

They also note that a high-protein intake could cause osteopenia (low bone mineral densitiy) due to the leaching of calcium from the bones, which could, in the future cause osteoporosis (brittle and weak bones). (9)

Protein and the Kidneys

Studies have shown that healty active subjects ingesting protein according to the recommended dietary allowance are not at risk of kidney disease. However, those who are sedentary, or have kidney issues should not adopt a high-protein diet.

There is also evidence that a high-protein diet based on animal sourced protein could strain the kidneys more than seafood or plant-based protein.

Risk of kidney stones

Studies have shown that animal protein increases the excretion of oxalate, a compound that can combine with calcium to form kidney stones. Research (1) found that 10 healthy adults following a low carbohydrate, high protein diet (similar to a Ketogenic Diet; learn more about the Negative Aspects of a Ketogenic Diet) for two weeks, followed by a restricted carbs diet for four weeks increased acid excretion through the kidneys by up to 90% in some of the subjects. Their "urinary calcium levels also rose sharply" showing that these diets may also increase the risk of bone loss due to calcium leaching.

Similar outcomes were found in another paper (2) that stressed that "For patients with or at high risk for kidney disease, the ketogenic diet may further tilt the risk/benefit ratio unfavorably by producing kidney-specific risks."

These results were also echoed by a Vasconcelos, Bachur and Aragao (3) who reported that "chronic and without professional guidance use of whey protein supplementation may cause some adverse effects specially on kidney... function."

Risk of Chronic kidney disease (CKD)

Another study analized bodybuilders; they don't only consume protein, but also use androgenic steroids, high doses of vitamins A, D and E as well as misuse of diuretics. Their study found that "there is little evidence that high-protein diets and moderate creatine supplementation pose risks to individuals with normal kidney function though long-term high protein intake in those with underlying impairment of kidney function is inadvisable". (4)

The Source of the Protein is important

A metanalysis that reviewed studies involving over 148,000 participants (5) found that a "lower CKD risk [was] significantly associated higher-level dietary total, plant, or animal protein (especially for fish and seafood) intake."

This finding seems to contradict the conclusions of the studies mentioned further up. The authors, however recommend interpreting this finding with caution. They point out the following:

• "Previous studies revealed that high-level of red meat and processed meat intake significantly increased the incidence of CKD."
• There is strong evidence that plant-protein promotes kidney health. This study found that a high-level intake of plant protein lowered the risk of CKD by 23%.
• Experiments with mice show that a diet rich in animal protein causes more inflammation in comparison to those fed with plant protein.
• Diets high in plant protein and low in animal protein contain higher levels of some amino acids (glutamic acid, cystine, proline, phenylalanine, and serine) which alters the nitrogen and acid loads on the kidneys.
• Plant based protein is rich in dietary fiber, impacting on the gut microbiome and lowering inflammation and "reducing the occurrence of CKD."
• This study found that fish and seafood protein lowered the risk of CKD by 16% and it has an inverse correlation (the more seafood and fish protein ingested, the lower the risk of CKD)
• Two of the studies analyzed by the authors were from Korea and Japan, where the main animal protein source is fish and seafood (not beef or pork). When they removed the data of these two studies the benefits of animal protein became non-significant.

The authors suggest that the effect of seafood protein is due to the long-chain n-3 polyunsaturated fatty acids (LCPUFAs) found in fish and seafood.

Other studies report the same effect (2): the Atherosclerosis Risk in Communities Study showed that those eating most red/processed meat had a higher risk of CKD than those eating the least.
These studies also showed that "substituting one serving of red meat with a plant-based protein such as legumes was associated with a 31%–62.4% reduced risk of CKD." (2)

Liver

Vasconcelos et al. also pointed out that liver function was also altered, being the liver (together with the kidneys) the main organs affected by "the chronic and abusive use of whey protein." Adding that this was aggravated for those who had a sedentary lifestyle.

They also found that some studies linked whey protein to aggravation of aggression, presence of acne, and modification of the microbiota." (3)

Protein Quality

The quality of the protein influences how easily the body can digests it. The Food and Agriculture Organization (FAO) defined the protein digestibility corrected amino acid score or PDCAAS to measure how different protein is absorbed by the body. The table below gives some examples. The higher the score, the more digestible is the food. (14)

The ISSN reports that "Milk-derived casein, egg white powder, and soy protein isolate are also classified as high quality protein sources," with 100 points on the scale. (9)

The International Society of Sport Nutrition recommends consuming the protein within the time frame of their exercise session, including before, during and after.

Closing Comments

It seems clear that the RDA for protein is adequate for healthy sedentary adults, but for those who are over 65 years old, and those who exercise intensly, a higher intake of protein is necessary.
There are certain health risks linked to a high-protein diet, but healthy people don't seem to be affected by them.

The intake of protein through a balanced diet, using plant-based or seafood/fish is healthier than one based only on animal protein. Whey protein supplements are a sensible way to increase protein intake.