Doctors who removed 420 kidney stones from a man in Dongyang, Zhejiang Province are blaming the condition on his love of local tofu, local media reported Friday.

The man surnamed He recently underwent two hours of surgery at the Dongyang People's Hospital to extract the densely-packed stones and over 100 calculus particles from his left kidney.

A CT scan during a visit to the hospital late last month for abdominal pain revealed his kidney was filled with 420 stones.

However it was when He explained his daily diet of gypsum tofu, a local food with a high concentration of Calcium sulfate, that doctors believed they found their culprit.

"Soy products, especially gypsum tofu, are very high in calcium, the excess of which cannot be excreted from body without a sufficient intake of water," said Wei Yubin, a doctor at the hospital.

According to He's medical records dating 20 years ago, doctors found about 10 stones in He's kidney and uterer. He had opted to forego surgery to remove the stones.

Qianjiang Evening News