The discovery of a natural fruit extract capable of dissolving calcium oxalate crystals, the most common component of human kidney stones, could be the first advance in the treatment of kidney stones in 30 years. Kidney stones are small, hard mineral deposits that form inside the kidneys, affecting up to 12 percent of men and seven percent of women. High blood pressure, diabetes and obesity can increase the risk, and the reported incidence is on the rise. Preventive treatment for kidney stones has not changed much over the last three decades.
Doctors recommend that patients who are at risk of developing stones drink plenty of water and avoid foods rich in oxalate, such as rhubarb, okra, spinach and almonds. They often prescribe taking citrate (CA), in the form of potassium citrate, a supplement that can slow crystal growth, but some people are unable to tolerate the side effects. Now researchers have found that the compound hydroxycitrate (HCA), a derivative of citric acid found in a variety of tropical plants, is an effective inhibitor of calcium oxalate crystal growth and that, under certain conditions, it is actually able to dissolve these crystals.
The head-to-head studies of CA and HCA determined that while both compounds inhibit the growth of calcium oxalate crystals, HCA was more potent and displayed unique qualities that are advantageous for the development of new therapies. Researchers recorded the calcium oxalate crystals actually shrinking, rather than just inhibiting growth, when exposed to specific concentrations of HCA. In human trials it was also shown that HCA is subsequently excreted through urine, a requirement for the supplement to work as a treatment.
However, the study authors caution that long-term safety, dosage and additional human trails are needed, before the supplement can be recommended as a treatment for people with chronic kidney stone conditions.