Sipping a soft drink in the spring sunshine – a wonderful feeling after a long walk. But drinking sweet lemonades shouldn’t become a habit. As a study by Yonsei University and Kwandong Catholic University (both South Korea) has now shown, regular consumption of soft drinks can have health consequences for the kidneys.
South Korean researchers are studying the effects of soft drinks
As part of their study, the researchers led by Ga Young Heo analyzed the data from 127,830 people who were deposited in the UK Biobank. The study participants had filled out a questionnaire about their eating and drinking behavior at least once. They should also answer the question “How many glasses, cans or packets with a volume of 250 milliliters did you consume yesterday of sugar-sweetened, artificially sweetened drinks or natural juices?”
On average, the scientists observed the test subjects over a period of ten years. Meanwhile, 4,459 of them had developed chronic kidney disease.
After the evaluation, the researchers came to the following conclusion:
The study participants who consumed more than 250 milliliters of sugar-sweetened or artificially sweetened drinks daily had a higher riskto suffer from chronic kidney disease. The scientists calculated the so-called hazard ratio (HR). This describes the probability with which an event will occur in a subject during the observed period. If it is above 1, the risk is increased. As a result, study participants were more susceptible to chronic kidney disease.
Specifically:
Subjects who consumed more than one glass (250 milliliters) of one daily had the greatest risk artificially sweetened drink (HR 1.26), even when consuming up to 250 milliliters the risk was already slightly increased (HR 1.10). The second highest risk was for people who consumed more than 250 milliliters daily sugar-sweetened drinks consumed (HR 1:19). The subjects who drank more than 250 milliliters of natural juice daily had no increased risk of chronic kidney disease (HR 0.99).
High consumption of sugary drinks can damage kidneys
Why sugar and artificially sweetened drinks can cause kidney disease? For one thing, sugar-sweetened drinks are high glycemic, meaning they increase blood sugar and insulin levels. High glycemic levels may further promote diabetes-related metabolic changes such as glucose interolency as well as insulin resistance and ultimately weight gain. The high sugar content can also greatly increase the flow rate of filtered fluid through the kidneys, thereby accelerating the decline in kidney function.
In addition, sugar-sweetened and artificially sweetened drinks are high in phosphoric acid, which is also a risk factor for chronic kidney disease.
“Light” or “Zero” – Soft drinks with sugar substitutes are even more harmful to kidney health
Since sugary drinks have a bad reputation, many people turn to artificially sweetened drinks as an alternative, which often have “light” or “zero” added to their names. However, these drinks have no advantage over high-sugar drinks when it comes to preventing kidney disease, the study says.
“In fact, consumption of artificially sweetened beverages is associated with a higher risk of developing chronic kidney disease, and body mass index has an indirect effect on the association between consumption of artificially sweetened beverages and chronic kidney disease,” the researchers write in of the study. But even regardless of calorie intake, long-term consumption of artificial sweeteners can increase the accumulation of adipose tissue and lead to weight gain.
Soft drinks with sweeteners can change the composition and function of the intestinal flora
A possible explanation for this is that artificially sweetened drinks change the composition and function of the intestinal flora. They could also ensure that the feeling of satiety decreases and the preference for sweetness increases. This can generally influence your own diet. It is also suspected that long-term consumption of the sweetener aspartame contained in diet drinks increases the production of free radicals in the kidneys and thus harms them.
While consuming natural juices did not increase the risk of chronic kidney disease, the researchers still advised people who are prone to it to avoid excessive consumption. Due to the high sugar content, natural juices can increase the risk of various metabolic diseases, which in turn can promote kidney diseases.
If you replace a can of soft drink a day with natural juices, the risk of chronic kidney disease decreases
At the same time, the scientists found that natural juices can reduce the risk of chronic kidney disease – if they are consumed as a replacement for sugary and artificially sweetened drinks. This is because natural juices also contain nutrients such as vitamin C and potassium, which can lower blood pressure and relieve inflammatory processes.
The effect was strongest when the test subjects gave up one serving (i.e. 250 milliliters) of artificially sweetened drinks per day and instead drank the same amount of natural juice. Then the risk decreased by 9.9 percent. Water as a substitute reduced the risk by 8.6 percent.
Scientists admit weaknesses in the study
However, the researchers also pointed out the weaknesses of their own study. In particular, the questionnaire on eating and drinking behavior over the past 24 hours is prone to errors. It could be that the study participants forgot certain information or incorrectly classified the types of drinks specified. In addition, it is not possible to determine habits and changes in eating and drinking with a 24-hour questionnaire. Nevertheless, if the test subjects had answered several questionnaires, similar results would have emerged.
The scientists’ final conclusion: “The results suggest that healthy beverage consumption habits could play an important role in preventing chronic kidney disease.”
How to protect your kidneys
Aside from consuming soft drinks in moderation, there are other ways you can protect your kidneys. In an interview with FOCUS online, Werner Riegel, Chairman of the German Kidney Foundation, gives eight tips:
Check your blood pressure regularly. Check your blood sugar levels. Go for a check-up. Stop smoking. Prevent kidney stones and urinary tract infections. Take in little salt and phosphate. Get enough exercise. Eat little meat