A 10-year clinical trial has shown that consuming certain fruits and vegetables can help people with chronic kidney disease (CKD) reduce hospital visits associated with excess acid in the body. The results were presented at the American Society of Nephrology (ASN) Kidney Week, held in Denver from 22 to 25 October.
The study involved 108 adults with stage 3 chronic kidney disease and metabolic acidosis, a condition in which too much acid builds up in the body. Researchers divided the participants into three groups of 36 people each. One group consumed fruits and vegetables that improved the reduction of acid levels, a second group took sodium bicarbonate, while the third group received standard medical care. Both the fruit and vegetable diet and the sodium bicarbonate treatment were designed to reduce the acid level in the diet by 50 per cent. Participants were followed for 10 years.
Scientists recorded 115 hospital admissions and 166 emergency department visits across all three groups, and 34 participants required dialysis during the study. Sodium bicarbonate is often used to keep excess acid under control in patients with kidney disease. The study suggests that certain fruits and vegetables offer another successful way to manage this condition, with the potential benefit of fewer hospital visits. The results highlighted the importance of diet in keeping kidney disease under control as effectively as possible.
The fruits and vegetables in question have a low potassium content and high levels of fibre and antioxidants, which are key to reducing metabolic acidosis, or acid build-up. These include blueberries, strawberries, raspberries and cranberries, which have an extremely low potassium and phosphorus content and strong anti-inflammatory effects, as well as apples and pears, which contain fibre. Citrus fruits are recommended in moderate quantities, while pineapple and grapes are excellent options with low potassium levels.
Experts recommend low-potassium vegetables such as brassicas, including cauliflower, broccoli and cabbage, as well as root and bulb vegetables like carrots, onions and radishes. They also suggest cucumbers and courgettes, which have a high water content and low mineral content, making filtration easier. Patients with chronic kidney disease should consult their doctors before making significant dietary changes, as certain fruits and vegetables contain high levels of potassium, which can be dangerous for people whose kidneys cannot effectively excrete it from the body.
CKD is a permanent and progressive damage to the structure and function of the kidneys that lasts for more than three months. The most common causes of damage to kidney blood vessels are diabetes and high blood pressure, while other causes include genetic diseases, chronic inflammation, obesity and long-term use of certain medications.
Nimrit Goraya, one of the study's authors, said: "These findings support the assessment of dietary interventions in chronic kidney disease not only at the individual level, but also at the population level, as the cumulative clinical and economic benefits can be very significant. They also highlight the potential value of investing in fruits and vegetables as a treatment strategy that contributes to quality of life, especially when a favourable clinical outcome can be achieved without increasing total costs."
