Many research studies have shown that lifestyle interventions, such as exercise programmes or weight loss, in people with impaired glucose tolerance (those at high risk of diabetes) can prevent progression to overt type 2 diabetes. However, until now, there has been a lack of high quality, randomized controlled trial evidence to prove that lifestyle interventions prevent deaths from cardiovascular disease, such as heart attacks and stroke, in these people.The risk of death from all-causes and cardiovascular diseases among people with type 2 diabetes is more than twice that of people of a similar age without diabetes. Logically, if lifestyle interventions reduce the risk of diabetes they should also reduce the excess risk of death, particularly from cardiovascular disease. However, without proof that lifestyle interventions will lead long-term health benefits such as reducing death rates in high-risk people, it is difficult for doctors to recommend it to their patients as an effective preventive therapy. In new research published in The Lancet Diabetes & Endocrinology journal, Professor Guangwei Li of the China-Japan Friendship Hospital, Beijing, China, and colleagues, present the results from the 23-year follow up of the Da Qing Diabetes Prevention Study, a randomized controlled trial, which showed that people in China with impaired glucose tolerance randomized to lifestyle interventions had significantly reduced death rates from cardiovascular disease and all-causes, compared to those patients randomized to the control arm. The investigators enrolled 438 patients assigned to intervention clinics, and 138 patients were assigned to control clinics. The study intervention lasted for 6 years, and patients were then followed up for 23 years. At the end of the follow up period, cumulative incidence of death from cardiovascular disease was 11·9% in the lifestyle intervention group, versus 19·6% in the control group, and death from all causes was 28·1% in the lifestyle group versus 38·4% in the control group. The difference between groups for both outcomes was statistically significant. Professor Nick Wareham of Cambridge University, UK, and author of a linked Comment on the study, describes the results as "a real breakthrough, showing that lifestyle intervention can reduce the risk of long-term cardiovascular consequences of diabetes."