A compound found in citrus fruit can dissolve calcium oxalate crystals, which form the most common kind of human kidney stone, according to research at the University of Houston.
The researchers say that the study could lead to the first significant new treatment of kidney stones for 30 years.
Kidney stones are small, hard mineral deposits that affect about one in 10 people. The reported incidence rate is rising.
The study, published in the online edition of Nature, provides the first evidence that the compound hydroxycitrate is an effective inhibitor of calcium oxalate crystal growth and that, under certain conditions, it can dissolve these crystals.
Hydroxycitrate, found in the Asian garcinia cambogia fruit, was tested on seven volunteers who took the supplement for three days, which allowed the researchers to establish the compound is excreted through urine, which is required for the treatment to work.
The researchers used atomic force microscopy, or AFM, to look at the interactions between kidney stones and HCA under realistic conditions. The images showed the crystals shrinking when exposed to specific concentrations of HCA.
Jeffrey Rimer, the study’s lead author, said that although the research establishes the groundwork for an effective drug, questions still remain. Additional human trials to establish the long-term safety and dosage are needed.
‘But our initial findings are very promising. If it works in vivo, similar to our trials in the laboratory, HCA has the potential to reduce the incidence rate of people with chronic kidney stone disease.’
About 15 per cent of men and five per cent of women in Britain develop a kidney stone at some time in their lives, most commonly between the ages of 20 and 40, and my patients who suffer from them tell me they cause the most excruciating pain they have ever experienced as they are being passed from the kidney into the bladder. They recur in at least half of all sufferers so anything that can help reduce this risk is always worth a look.
Kidney stones are often built around calcium oxalate crystals, and this research suggests that hydroxycitrate (HCA), a compound found in citrus fruit, could slow or even dissolve the formation of these crystals.
However, this research was only done in people taking HCA supplements over a three-day period, and at best the conclusion is ‘promising’. Further studies will now undoubtedly follow but they need to be bigger and over a far longer time period.
Research score: 2/5