Chronic renal failure – also known as renal insufficiency – ends with dialysis. With the right diet, you can not only prevent kidney disease. Nutrition can also be used therapeutically and support the healing process.
A healthy diet prevents chronic kidney disease
Chronic kidney disease (also called chronic kidney failure or renal insufficiency) refers to a disease in which the kidneys continuously lose their ability to function over months or years. Pollutants and metabolic waste products are less and less able to be filtered out of the blood. In the final stages, patients must therefore take regular dialysis treatment or hope for a kidney transplant.
Life expectancy decreases with the disease since patients suffer more frequently from infectious diseases (e.g. pneumonia) and cardiovascular diseases (high blood pressure up to strokes) than people with healthy kidneys. High blood pressure occurs in renal failure because the diseased kidneys release a blood pressure-increasing hormone so that they can have better blood flow through the higher blood pressure and thus be able to function better. High blood pressure is not only a consequence of kidney disease, but it is also an important contributory cause.
In one study, scientists from the University of Virginia School of Medicine found that patients with chronic kidney failure eat fewer fruits and vegetables than people who don’t have the disease (6). It could be that low fruit and vegetable consumption is also a consequence of chronic kidney disease. However, previous studies have indicated that a healthy diet can protect against chronic kidney disease, such as a study published in the Clinical Journal of the American Society of Nephrology shows. Considering the 500 million people affected (worldwide), a healthy diet could not only massively reduce the suffering of the individual and his family, but also the costs of the health systems ( 1 ).
The risk of chronic kidney disease decreases by 30 percent
For the review, researchers from the medical faculty of Bond University in Queensland/Australia analyzed all relevant studies (which had been published up to February 2019) with a total of over 630,000 participants. The participants in the 18 studies received scientific support for an average of 10.4 years.
It was found that those who had a healthy diet could prevent chronic kidney disease. The risk of becoming a victim of such a disease fell by 30 percent. “Healthy eating” here means eating that meets the following criteria:
- A lot of fruits and vegetables
- Plenty of nuts and legumes
- Whole grain products
- Little animal products, fish and low-fat dairy products
- Little red meat and few processed meat products
- Little salt
- Rarely or never sugar-sweetened beverages
A healthy diet prevents those diseases that lead to kidney damage
“Our results support existing evidence for the benefits of a healthy diet – such as the Mediterranean diet, the DASH diet or even a diet according to official guidelines,” said study author Dr. Jaimon Kelly. After all, it is known that a healthy diet can be used very well to prevent many chronic diseases, e.g. for the prevention of type 2 diabetes, cardiovascular diseases (e.g. high blood pressure, arteriosclerosis), dementia and cancer.
Since type 2 diabetes and high blood pressure are among the most important diseases that lead to chronic kidney disease in the first place, a healthy diet can be used twice to prevent diabetes and high blood pressure and thus automatically kidney disease.
Eating healthy also promotes the healing of these diseases!
But if you already have type 2 diabetes and high blood pressure, you can also achieve a lot with a healthy diet. In many cases, type 2 diabetes is even curable if you make your lifestyle and diet healthier – and blood pressure usually levels off again if you eat and live healthily.
But even the progression of chronic kidney disease that already exists can be significantly slowed down if you change your diet afterward ( 3 ). Exactly what the diet should look like depends on the severity of the disease.
The right nutrition for the kidneys
If dialysis is not yet required, the diet can usually be switched to the diet described here without any problems, as this automatically also takes into account the basic rules of a diet that is healthy for the kidneys. These rules are:
- Not too much protein, but not too little either (stay below 1.3 g, preferably between 0.8 and 1 g protein per kilogram of body weight)
- Not too much salt, it’s best to stay at 5 to 6 g per day, taking into account the high salt content of many ready-made products (salty snacks, sausage, cheese, baked goods, ready-made soups, etc.), which means that it is better to avoid them as much as possible and its meals prepared from fresh ingredients and seasoned with little salt.
- Sick kidneys can no longer excrete phosphates as well. Rising phosphate levels, however, increase the risk of bone disease and calcification of the vessels with subsequent cardiovascular events. Since phosphates are found in protein-rich foods in particular and also in many ready-made products (in many types of sausage and cheese, baked goods with baking powder, soft drinks, etc.), limiting phosphate consumption is not a problem, especially with a healthy, low-protein diet.
- Plenty of salads, vegetables, fruit and herbs: These foods are high in potassium – and kidney patients in particular are often advised to eat a low-potassium diet. So what to do?
Potassium in Kidney Disease: Yes or No?
Anyone who has already been diagnosed with “chronic kidney disease” usually receives a doctor’s recommendation to consume less potassium (maximum 1500-2000 mg). However, fruits and vegetables are the foods with the highest potassium content. As mentioned above, kidney patients are particularly susceptible to cardiovascular diseases. The heart and circulatory system, however, absolutely need sufficient potassium. If you eat low in potassium, the risk of secondary diseases increases ( 7 ).
In a review from 2020, 9 studies on this topic were evaluated. It was shown that a high-potassium diet (more than 2500 mg potassium per day) in renal insufficiency (stage 1 and 2) slowed the progression of the disease and that at the same time a low-potassium diet promoted the disease. So if you have kidney failure in the early stages, you should never eat low in potassium.
The diet only has to be low in potassium if high potassium values are actually measured, which is usually only the case in the final stage or when dialysis is required. Healthy foods rich in potassium, such as herbs, vegetables and salads, do not have to be avoided, as was often claimed in the past. On the contrary.
Eating vegetables and fruit can correct metabolic acidosis as well as giving sodium bicarbonate. In metabolic acidosis, the kidneys are no longer able to excrete the acids produced during metabolism, which contributes to an even more rapid loss of kidney function.
Kidney specialist Dr. Julia J. Scialla from the University of Virginia points out that doctors should not scare kidney patients in particular by warning them about foods rich in potassium. Of course, fruit and vegetables not only contain potassium, but also vitamins, fiber and antioxidant and anti-inflammatory phytochemicals, which those affected are now missing and further weaken their health.
Prevent kidney disease with a healthy diet
“With the help of our study, we could now develop prevention programs for chronic kidney disease,” hopes Dr. Kelly. Because – as explained above – a healthy diet can not only prevent kidney disease but also slow down its progression if it already exists.
To do this, however, it would first be necessary to train doctors in nutrition so that patients can be given appropriate advice right from the start, because medical studies hardly cover the area of nutrition at all, so it is better to become active yourself and take responsibility for a healthy diet and lifestyle or start looking for a doctor with expertise in the field of nutritional medicine.