A Mediterranean diet rich in fruits and vegetables -- already known to protect against heart disease -- also appears to help ward off diabetes, Spanish researchers said on Friday.

The study published in the British Medical Journal showed that people who stuck closely to the diet were 83 percent less likely to develop type 2 diabetes than those who did not.

"The new thing is that we have been able to assess adherence to a Med diet and the incidence of diabetes in people who were initially healthy," said Miguel Martinez-Gonzalez, an epidemiologist at the University of Navarra in Spain, who led the study. "We didn't expect such a high reduction."