The findings indicate that a drug known as metformin, used to control glucose levels in the body and already known to exhibit anticancer properties, could offer prognostic and prophylactic benefits to people without diabetes.
Scientists from Cardiff University set out to compare the survival of diabetes patients prescribed with metformin with patients prescribed with another common diabetes drug called sulphonylurea.
The life expectancy of these cohorts was also compared against non-diabetics who were matched based on criteria that included age, gender, same general practice, smoking status and clinical status.
"Patients treated with metformin had a small but statistically significant improvement in survival compared with the cohort of non-diabetics, whereas those treated with sulphonylureas had a consistently reduced survival compared with non-diabetic patients," said lead author Professor Craig Currie from Cardiff University's School of Medicine.
"This was true even without any clever statistical manipulation.
"Surprisingly, the findings indicate that this cheap and widely prescribed diabetic drug may have beneficial effects not only on patients with diabetes but also for people without, and interestingly, people with type 1 diabetes," said Currie.
"Metformin has been shown to have anti-cancer and anti-cardiovascular disease benefits. It can also reduce pre-diabetics' chances of developing the disease by a third.
"This does not mean that people with type 2 diabetes get off Scott free. Their disease will progress and they will be typically switched to more aggressive treatments.
"People lose on average around eight years from their life expectancy after developing diabetes. The best way to avoid the condition altogether is by keeping moderately lean and taking some regular light exercise," Currie said.
The study was published in the journal Diabetes, Obesity and Metabolism.