The research, by scientists at the University of Oxford's Nuffield Department of Population Health (NDPH) and several Chinese public health bodies, looked at the effects of fruit consumption in over half a million people in ten different areas of China.
They found that those who regularly ate fruit were 12% less likely to fall victim to diabetes than those who rarely or never ate fresh fruit.
Among those already suffering from the disease, those who ate fresh fruit more than three days a week had a 17% lower relative risk of dying from any cause, and a 13-28% lower risk of developing diabetes-related complications, than those who ate fruit less than once a week.
Previously, some have believed that diabetics' consumption of fresh fruit should be restricted as it contains high levels of sugar.
Study author Dr Huaidong Du of NDPH said: "This is the first large prospective cohort study demonstrating clear beneficial associations of fresh fruit consumption with both development and progression of diabetes taking into account the potential impacts from a range of other socioeconomic and lifestyle factors."
Diabetes affects more than 400 million people globally, a quarter of them in China, where fresh fruit consumption is lower than in the West.
The authors describe the new findings as "important for health promotion", since there has so far been limited evidence linking fruit consumption to diabetes prevention.
The results are published in PLOS Medicine.