After controlling for various factors, the team found that drinking two or more colas a day — whether artificially sweetened or regular — was linked to a twofold risk of chronic kidney disease.

The empty house, in a middle-class corner of southern California, is two storeys high and boasts a three-car garage. Roses bloom around a kidney-shaped swimming pool, which is green with algae.

In 2006, these elderly patients had a 7.3 percent chance of getting a kidney transplant within three years of their first treatment for kidney failure. That rate was two times higher than in 1995.