The side effects of whey and protein powders are the talk of the town. According to some, they are dangerous for numerous organs, including the kidneys. However, this belief is based on a misconception.
Scientific research tends to prove that a protein-rich diet increases kidney activity. However, these studies do not indicate that whey and protein powders promote kidney problems.
Kidney disease is often multifactorial. Within reasonable limits and in the right doses, eating a higher protein diet is not harmful to the kidneys.
That said, doctors rightly advise against taking these protein supplements for people with kidney disease. In the case of severe kidney disease, consuming protein powders can worsen symptoms and accelerate disease progression.
Hence the need to take care with diet. People in this situation are well advised to consult a doctor before embarking on any kind of diet, especially if the liver is also previously affected. In such cases, the entire diet must be monitored.
How do protein powders affect the kidneys?
Many researchers have studied the effects of protein on the kidneys. In 19231 and again in 19312, scientists discovered that the urine of people on a high-protein diet had high levels of urea and creatinine.
Urea is a substance released by the body when proteins are used. It is essential for proper management of the body's nitrogenous waste.
Creatinine is produced by the breakdown of creatine. Supplementation as part of a training program, or heavy consumption of red meat, leads to an increase in creatinine production, which ends up in the urine.
A study has shown that this increase in urea and creatinine levels is linked to increased blood flow to the kidneys. This phenomenon is not only caused by protein consumption. Physical activity also stimulates intra-renal blood flow, to the point of increasing " glomerular filtration rate " or GFR. This corresponds to the volume of liquid that the kidneys filter in one unit of time.
These findings demonstrate that a protein-rich diet increases kidney activity. However, there is no evidence that protein subsequently increases the risk of kidney disease.
Can whey and protein "strain" your kidneys?

So here's the question to answer: can relatively high DFR over a long period of time ultimately lead to kidney problems? Against all odds, it would appear not. High DFR does not go hand in hand with kidney problems.
In women, for example, pregnancy is accompanied by a 60% increase inDFR3. Yet pregnant women do not develop minor disorders or serious illnesses before, during or after pregnancy.
The same is true of people who have lost one of their kidneys following surgery! Despite a high DFR, they do not develop serious illnesses or long-term renalfailure4.
Under these conditions, a high DFR does not lead to kidney problems under normal conditions. Whey is therefore not harmful to your kidneys. A conclusion confirmed by two clinical studies5-6.
Can I take whey without worrying about my kidneys?
So we've once again dispelled a common misconception about protein powders. After all, whey isn't dangerous for your kidneys, since a well-dosed high-protein diet isn't. But this statement should be taken with a grain of salt. However, this statement should be taken with a grain of salt. In fact, protein used in excess in the presence of kidney disease can be an aggravating factor.
A high-protein diet accelerates the progression of pre-existing kidney disease. This phenomenon is therefore only observed in people already suffering from this type of condition. This is why whey and protein powders are not recommended for people suffering from kidney and/or liver failure.
For the sake of good health, athletes and body-builders with any doubts can always undergo a medical check-up before starting supplementation. The results will confirm that whey or any other protein powder is safe to consume.
As a general rule, young, healthy people need not fear kidney problems. They should, however, take care not to exceed recommended doses.
Remember that athletes wishing to maintain their muscle mass should consume between 1.3 and 1.6 g/kg/d of protein. On the other hand, protein intake should be close to 2 g/kg/d if you want to promote mass gain.
It is not necessary to exceed 2g/kg/d of protein. Excess protein will be burned by the body and may lead to acidification. This will unnecessarily increase renal workload, as well as the excretion of waste products such as urea.

Medical update on kidney failure
There are two forms of renal failure: chronic renal failure (CRF) and acute renal failure (ARF). The former is a slowly progressing disease leading to the irreversible destruction of the kidneys. The second form is induced by intoxication, haemorrhage or infection. In the latter case, the disease is reversible with appropriate management, and is characterized by a very low recurrence rate.
Recent research has shown that these conditions are linked to genetic predisposition. Biomarkers can now be used to identify people at risk, so that they can be treated at an early stage. That said, hypertension and diabetes are considered the main co-morbidities associated with CKD.
The hyperglycemia associated with diabetes accelerates the destruction of small blood vessels in the kidneys. Hypertensives also suffer from poor vascularization, which progressively impairs kidney function. In this sense, the medical profession does not attribute these diseases to an excessively protein-rich diet.
However, the consumption of animal proteins should be monitored in people at risk of developing kidney failure. Vegetables should be preferred to meat and fish. Hence the need for a medical check-up. If you suffer from diabetes or hypertension, you should also take the time to consult a doctor before starting supplementation.
However, a 2009 study7 showed that whey is safe for people with type II diabetes. Quite the contrary! Under the right conditions of use, this dietary supplement proves useful for regulating blood sugar levels over the long term.
In hypertensive individuals, a 20194 study showed that taking protein powder had no impact on blood pressure. So for those of you who think that proteins can cause heart problems, rest assured that supplementation does not expose you to any cardiovascular problems.
In any case, we encourage you to consult a doctor before starting whey if you have a particular health problem.
Does whey have any side effects?
At this stage, it would appear that whey represents no health hazard. Science supports the view that a well-dosed high-protein diet cannot be considered a cause of kidney damage.
Furthermore, whey is not inadvisable for people with high blood pressure or diabetes. Are we to understand that this dietary supplement is totally safe, whatever its form?
Well, no! In fact, commercially available whey contains more than just whey protein. The finished product also often contains additives designed to improve its taste for consumers. However, studies carried out over the last few years have not confirmed the safety of these components.
Scientists even warn athletes about certain additives, such as sucralose9. This widely-used sweetener gives a sweet taste to sugar-free protein powders. This molecule is said to disrupt the brain by habituating it to very sweet tastes, without having the appropriate insulin response.
This will ultimately lead consumers to eat more sugar in their overall diet. At the same time, sucralose promotes certain disorders such as diabetes, and disrupts intestinal flora.
Lecithin is also a widely-used additive, now implicated in chronic inflammatory bowel disease. We take a closer look at the importance of lecithin-free whey.
Whey also contains many other additives with unknown effects. As a result, this product can present a variety of side effects, depending on the brand.
How can I take whey without worrying about my health?

As you can see, the most important thing is to choose a good quality whey. We can only recommend a whey without additives. Choose your whey according to its composition, and avoid products with a long list of ingredients or additives. Learn how to store your whey properly, so that you can enjoy all its benefits after opening.
Those suffering from lactose intolerance will need to be much more vigilant. Although this supplement is in principle lactose-free, some of them may still contain significant quantities.
For the more sensitive, native whey isolate may be a far more interesting option. In the case of whey isolate, the milk is further filtered to remove virtually all lactose, resulting in a whey with a protein concentration of over 75%.
Always choose a dietary supplement produced in France. French legislation guarantees maximum traceability of ingredients, so there are no nasty surprises. What's more, if you opt for wheys produced in short circuits, in direct contact with local producers, this choice limits the ecological impact of production. Choosing a whey produced thousands of kilometers away means releasing a huge amount of CO2 into the atmosphere to transport the product.
Finally, it's important to remember that protein powders should only be consumed as part of a sports routine. Without sporting activity or a varied, balanced diet, these dietary supplements may even, paradoxically, encourage weight gain (fat). It's worth remembering that excess weight is at the root of many health problems, from cardiovascular disease to diabetes.
Once again, we encourage you to consult a dietician or nutritionist to set up an appropriate nutrition program. The advice of this specialist will be essential for all those suffering from a chronic disease, in addition to the recommendations of your doctor.
To find out more about the dangers of dietary supplements, see our various reports on the subject:
- Does whey protein = danger?
- Are BCAAs harmful to the kidneys?
- Can a teenager take whey?
- What are the dangers of casein?