Citrus fruit ‘cure’ for painful kidney stones

‘Compound found in plant ‘dissolves crystal deposits’

Painful kidney stones could be dissolved by a natural citrus fruit extract, suggests new research.

The study showed that the compound – hydroxycitrate (HCA) – is able to inhibit the growth of kidney stones – and even dissolve the crystals.

The discovery marks the first advance in kidney stones treatment in more than three decades.

Kidney stones are small, hard mineral deposits that build up inside the kidneys, affecting around 12 per cent of men and seven per cent of women.

They are composed predominantly of calcium oxalate crystals and are more prevalent in those with high blood-pressure, diabetes or obesity – and are on the rise.

But the researchers found HCA was effective in slowing the build-up of calcium oxalate under certain conditions.

HCA is naturally found in the Garcinia Cambogia fruit, used widely in south east Asia.

The study, published online by the journal Nature, revealed ‘very promising’ results in a study of people who took HCA supplements over a three-day period.

Preventative treatment for kidney stones has barely changed in the last 30 years.

Doctors advise patients to drink plenty of water and avoid oxalate-rich food, such as rhubarb and almonds.

They often prescribe the supplement potassium citrate, which can slow crystal growth – but some people cannot tolerate the side-effects.

Collaborator John Asplin, a nephrologist at Litholink Corporation, a private hospital for people with kidney problems, suggested HCA as a possible treatment.

Citrate and HCA are chemically similar, and both are available as a supplement.

Lead author Dr. Jeffrey Rimer, of the University of Houston, said: “HCA shows promise as a potential therapy to prevent kidney stones – HCA may be preferred as a therapy over potassium citrate.”

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.

But it turned out that it was correct. Once the team confirmed that it was possible to dissolve crystals in supersaturated solutions, they then looked at reasons to explain why.

They discovered that HCA formed a stronger bond with that crystal surfaces, leading to the crystals being broken down.

HCA was also tested in human subjects, as seven people took the supplement for three days, allowing researchers to determine that HCA is excreted through urine, a requirement for the supplement to work as a treatment.

While the researchers established the groundwork to design an effective drug, questions remain – long-term safety, dosage and additional human trials are needed.

“But our initial findings are very promising,” they said.

“If it works in vivo (in real life), similar to our trials in the laboratory, HCA has the potential to reduce the incidence rate of people with chronic kidney stone disease.”