Whey protein is one the most well-known supplements on the planet.
However, there are some concerns about its safety despite the many health benefits.
Some people claim too much whey protein can cause damage to the liver and kidneys, and even osteoporosis.
This article presents an evidence-based overview of side effects and safety concerns associated with whey protein.
Whey protein is a well-known dietary and fitness supplement.
It is made from whey which is the liquid that separates milk during cheese-making. The whey protein is then processed into powder form by spray drying.
There are three types of whey proteins. They are all processed differently (1).
* Whey protein concentrate contains approximately 70-80% protein. This is the most popular type of whey protein. It contains more milk fat, lactose and minerals than other types.
* Whey protein isolate: At least 90% of the protein is contained. It is more refined, has less lactose, and fat, and also has fewer beneficial minerals.
* Whey protein hydrolysate – This form is pre-digested and allows your body to absorb it quicker.
Whey protein is a popular option for athletes, fitness enthusiasts, and anyone looking to gain muscle or lose weight.
It can be used to recover from exercise, increase muscle strength, and lose weight.
Whey protein is a complete protein source, which means it contains all essential amino acids. Essential amino acids cannot be made by the body, so it is important to consume enough.
Mixing whey protein with water or another liquid can make it easy to consume.
Some people are worried about its safety, despite its many health benefits.
Whey protein is safe and convenient for most people.
Summary: Whey Protein is safe. It can help you gain muscle, strength, and lose weight.
The majority of side effects associated with whey protein are related to digestion.
People with problems digesting whey protein may experience symptoms like bloating, gas and stomach cramps, as well as diarrhea ((5)).
Most side effects of lactose intolerance are caused by this.
Whey protein is primarily made up of lactose. Lactose-intolerant people don’t produce enough lactase to help your body digest lactose (5).
Furthermore, lactose intolerance can be extremely common and affects up to 75% worldwide.
Switch to whey protein isolate powder if you are lactose intolerant.
Whey protein isolate has a more refined taste and contains a lower amount of fats and lactose than the concentrate. Whey protein isolate is safe for people with lactose intolerance (7).
You can also try non-dairy protein powders like soy, pea or egg, rice, or hemp protein.
> Summary: People with lactose intolerance may experience uncomfortable symptoms when consuming whey protein. You can switch to non-dairy protein powders or whey isolate powder if you have uncomfortable symptoms.
People with a cow’s milk allergy might be allergic to whey protein because it comes from cow’s dairy.
However, adults with cow’s-milk allergies are rare. As many as 90% of those suffering from them outgrow them before the age of three ((8)).
A cow’s milk allergy can cause hives, rashes and facial swelling. It may also lead to swelling of the throat, tongue, throat, and nose.
Anaphylaxis can be triggered by a milk allergy in cows. This is a life-threatening allergic reaction.
It is important to remember that although a cow’s-milk allergy is uncommon in adults, it can have serious consequences.
A whey protein allergy should not be confused for lactose intolerance.
Allergies are caused by the body’s immune response to a particular protein. An enzyme deficiency is what causes intolerance, but it does not affect the immune system (10)
You can avoid cow’s milk protein allergies by using a non-dairy protein powder such as soy or pea, egg, rice, or hemp protein.
It’s best to consult your doctor if you aren’t sure if your symptoms are caused by an allergy or intolerance.
Summary: People who are allergic to cow’s milk might also be allergic to whey proteins. However, adults with cow’s milk allergies are rare.
Whey protein does not cause constipation.
A lactose intolerance can cause constipation in some people (11-12).
Constipation can be caused by a preference for whey protein over fruits and vegetables, especially if the diet is low in carbs.
Vegetables and fruits are great sources of fiber. This helps to form stool and encourages regular bowel movements (13).
You might feel constipated if you take whey protein. A soluble fiber supplement is also an option.
Whey protein can also be a bad choice if you are trying to replace whole foods with it.
Whole foods, particularly fruits and vegetables, have a lot of nutrients and are rich in minerals that can be beneficial for your health.
It is important to eat a balanced diet even though you are taking whey protein.
Summary: Whey protein can increase constipation risk and lead to nutrient deficiencies. These effects can be countered by eating a balanced diet.
Consuming high-protein meals can increase the pressure in the kidneys, causing them to filter more blood (14-15).
This does not mean that high-protein meals are bad for the kidneys.
Studies show that this is a normal bodily response, and not a cause of concern (16-17).
There is also no evidence to suggest that excessive protein can cause kidney damage in healthy individuals (16, 18).
A detailed review of 74 studies examining the effects of protein on the kidneys concluded that healthy individuals should not be restricted in their intake (18).
However, evidence suggests that high-protein diets can be dangerous for those with kidney disease.
Research shows that high-protein diets in people with kidney disease can further damage their kidneys (19, 20, 21).
You should consult your doctor if you have a kidney condition.
> Summary: There is no evidence to suggest that excessive protein can cause kidney damage in healthy individuals. People with a kidney condition or other health concerns should consult their doctor to determine if whey protein is appropriate for them.
There is no evidence that excessive protein can cause liver damage in healthy individuals (21).
The liver actually needs protein to repair itself, convert fats into lipoproteins, molecules that help remove excess fats, and to make sure it stays healthy (21).
A study of 11 obese women found that 60g of a whey-protein supplement reduced liver fat by around 21% in just four weeks.
It also reduced blood triglycerides approximately 15% and cholesterol about 7% (22).
One case report suggested that liver damage could have occurred in a 27-year-old male who took whey protein supplements (23).
He was also taking several other supplements. Doctors weren’t sure if he was taking any anabolic steroids (24).
This single case is not enough evidence to prove that whey proteins can cause liver damage, considering that there are thousands of people who consume whey protein every day without any liver problems.
However, people with cirrhosis (25, 26, a chronic liver disease) may be more sensitive to high levels of protein.
The liver is responsible for detoxifying harmful substances in the blood, such as ammonia (27).
The liver is unable to function properly in cirrhosis. A high intake of protein may lead to an increase in blood ammonia, which can cause brain damage (26, 28, 29).
Before you start taking whey protein if you have liver disease.
> Summary: In healthy individuals, there is no evidence that excessive protein can cause liver damage. People with liver disease should consult their doctor to determine if whey protein is safe.
There has been some debate about the relationship between protein intakes and bone health.
Some worry that too much protein could cause calcium to leach from bones, increasing the risk for osteoporosis (29). This is a condition characterized by porous and hollow bones.
This idea was inspired by earlier studies which showed that a higher intake of protein made urine more acidic (31, 32).
The body would then release calcium from its bones in order to buffer the acidic effects and neutralize them (31).
Newer research however has shown that calcium absorption is an effective way to counter calcium loss (32, 33).
Scientists found no evidence that too much protein is bad for bones health in 36 studies.
They concluded that more protein is actually good for bone health (34).
Numerous studies have also shown that older people who are more susceptible to osteoporosis should consume more protein to maintain strong bones (35 and 36).
> Summary: Whey protein does not cause osteoporosis. Whey protein may actually help to prevent this condition.
Whey protein can be eaten by most people and is safe.
Commonly, 1-2 scoops (25-50g) is the recommended daily intake. However, it is highly recommended to follow the instructions on the packaging.
It is unlikely that you will get more benefits if your current intake of protein is sufficient.
You may experience bloating, nausea, cramps, or diarrhea if you take whey proteins.
You can also try non-dairy protein powders like soy, egg, rice, or hemp.
> Summary: A daily intake of whey protein should be between 1-2 scoops (25-50g). You can try non-dairy or whey protein alternatives if you have digestive problems.
Whey protein can be taken safely by many people without any side effects.
It can cause diarrhea in people with lactose intolerance and may also be harmful to those who are allergic to cow’s dairy products.
Side effects may occur if you take non-dairy or whey protein isolate.
Whey protein is a great supplement, even with these exceptions. There are many studies that support its benefits in weight loss, strength, muscle building, and recovery.
