People enrolled in the study on diabetes prevention in China followed a diet and exercise program for six years, then were followed by researchers for another 23 years.
Over that time, there was a significant reduction in their risk of death from cardiovascular diseases -- such as coronary heart disease and stroke -- and death from other causes, the researchers found.
"This reduction in mortality appears to be due in part to the delay in the onset of diabetes resulting from the lifestyle interventions," said lead researcher Dr. Guangwei Li, of the department of endocrinology at the China-Japan Friendship Hospital, in Beijing.
For the study, Li's group randomly assigned 438 patients to the diet and exercise program, and another 138 patients to maintain their regular lifestyle.
Diets were designed to produce weight loss in obese or overweight participants, and to reduce carbs and alcohol intake in people of normal weight, the study authors explained.
The exercise segment of the program focused on increasing how much physical activity participants did during their leisure time.
After more than two decades of follow-up, the incidence of death from cardiovascular disease among those in the diet and exercise program was about 12 percent, compared with nearly 20 percent among those who did not change their lifestyles, the study found.
Moreover, the incidence of death from any cause was about 28 percent among those in the lifestyle-change group versus over 38 percent among the others, the researchers added.
Previous research has shown that for people with type 2 diabetes, the risk of dying from heart conditions and stroke is more than twice that of people without diabetes, Li noted.
"These [new] findings provide yet further justification to implement lifestyle interventions in people with high blood sugar, as clinical and public health measures to control the long-term consequences of diabetes," Li said.
The report was published April 3 in the online edition of The Lancet Diabetes & Endocrinology.
Dr. David Katz, director of the Yale University Prevention Research Center, said that "lifestyle is the best medicine has been established by an impressively consistent array of research findings spanning populations and decades."
Careful attention to eating well, being active, controlling weight and avoiding tobacco has been shown to reduce the lifetime risk of all major chronic disease by 80 percent, he said.
"This study shows first, that an intervention focused particularly on diabetes prevention has generalized benefits," Katz said. "This is not very surprising, since the causal and protective factors for all of the prevalent chronic diseases are interrelated. The same diet and activity pattern that helps prevent diabetes does the same for cardiovascular disease," he added.
"Second, and more surprising, this study suggests that a robust lifestyle intervention program of sufficient duration is a gift that keeps on giving, conferring benefit for years after it concludes," Katz said. "This offers important promise with regard to the cost-effectiveness of such interventions."
To learn more about type 2 diabetes, visit the American Diabetes Association.