We’ve known this for over 20 years
Type 2 diabetes is a huge and growing health problem globally, not just in the US. A 2001 study by Finish researchers asked whether diabetes could be prevented in high-risk persons using interventions designed to encourage a healthy lifestyle. Five hundred twenty-two overweight men and women with an average age of 55 years were randomly assigned to either the intervention group or the control (usual care) group. Each person in the intervention group received individualized counseling aimed at reducing weight, reducing intake of fat and saturated fat, increasing intake of fiber, and increasing the amount of physical activity. Supervised, individually tailored programs were offered to persons in the intervention group. These subjects were asked to meet five goals: 1) reduce weight by 5 percent, 2) reduce fat intake to less than 30 percent of total calories, 3) reduce saturated fat to less than 10 percent of total calories, 4) increase fiber intake to at least 15 grams per day, and 5) exercise at least four hours per week.
Subjects in the intervention group reported significant changes in their food intake: less fat, saturated fat, sugar and salt, and increased vegetables. The cumulative risk of diabetes for the intervention group over the six years of the trial was 58 percent lower than that of the control group. But here’s the stunning news: None of the 64 participants who achieved four or five of the study goals became diabetic. Not one. This randomized controlled trial demonstrated that diabetes is preventable in overweight, older adults who Eat Better and Keep Moving.
What about Chinese with impaired glucose tolerance?
The Chinese Da Qing Diabetes Prevention Study began in 1986 in 33 community clinics with 577 participants with an average of 45 years who had impaired glucose tolerance. Participants were randomized into one of four groups: 1) better diet, 2) increased physical activity, 3) both better diet and increased physical activity, and 4) control. After 6 years when the active intervention study ended and compared to the control group, participants in three intervention groups combined had 51 percent lower risk of developing diabetes. After an additional 14 years, during which no intervention occurred, participants in the three intervention groups combined had 43 percent lower risk of developing diabetes compared to the control group participants. Thus, the positive effect of the 6-year active intervention persisted for 14 more years.
What about Japanese with impaired glucose tolerance?
Research shows that lifestyle modification can prevent type 2 diabetes in patients with impaired glucose tolerance. Would an intensive lifestyle modification program prevent the development of type 2 diabetes in patients with impaired fasting glucose levels (100-125 mg/dL)? Japanese researchers randomized 614 patients with an average age of 49 years in the Zensharen Study for the Prevention of Lifestyle Diseases into one of two groups: 1) frequent intervention (FINT), and 2) control. Participants in FINT received individual instruction and follow-up support sessions from hospital and clinic medical staff at least 9 times over 36 months, with additional sessions if requested. Participants in the control group received only four sessions over 36 months. Both FINT and control group sessions were designed to achieve weight loss of 5 percent and increase physical activity.
After adjusting for confounders, participants in the FINT group had a significant 44 percent lower risk of developing type 2 diabetes after 36 months compared to participants in the control group. For participants with baseline HbA1c levels of more than 5.6 percent, those in the FINT group had significant 76 percent lower risk of developing type 2 diabetes compared to participants in the control group. Japanese persons with impaired fasting glucose can avoid type 2 diabetes. An intensive lifestyle intervention could be even more beneficial for patients with worse blood sugar status.
The Diabetes Prevention Program Outcomes Study
Effective prevention is needed to counter the worldwide epidemic of type 2 diabetes. A team of researchers investigated the long-term, beneficial effects of lifestyle intervention and metformin (a drug used to manage type 2 diabetes) on diabetes prevention, shown during the 3-year Diabetes Prevention Program (DPP). The DPP (1996–2001) was a randomized trial comparing an intensive lifestyle intervention or metformin (or a placebo) in a cohort at very high risk of developing diabetes. In 2002, 2,766 participants (88 percent) of the surviving DPP cohort members were followed in the DPP Outcomes Study until 2014. During DPPOS, the original lifestyle intervention group was offered healthy lifestyle reinforcement semi-annually and the metformin group received metformin.
During a mean follow-up of 15 years, diabetes incidence was reduced by 27 percent in the lifestyle intervention group and by 18 percent in the metformin group compared with the placebo group. At year 15, the cumulative incidences of diabetes were 5 percent in the lifestyle group, 56 percent in the metformin group, and 62 percent in the placebo group. Lifestyle intervention or metformin significantly reduced diabetes development over 15 years. Plus, those who did not develop diabetes had a lower prevalence of microvascular complications (such as amputations) than those who did develop diabetes. This result supports the importance of diabetes prevention.
What do type 2 diabetes experts say?
Five type 2 diabetes researchers recently reviewed points of agreement and controversy regarding prevention and treatment of type 2 diabetes. The centrality of nutrition to prevent type 2 diabetes is clear. Yet the medical system is not organized to give sufficient attention to patient nutrition and follow-up, especially in less developed countries. Evidence supports diets high in vegetables, fruits, whole grains, legumes, nuts, and dairy products. Experts generally believe that the Mediterranean dietary pattern, particularly with its emphasis on olive oil as the main source of fat, helps people avoid type 2 diabetes. Foods to avoid generally include processed red meat, refined grains, and sugars. The ideal macronutrient composition to reduce risk of developing type 2 diabetes remains controversial in part due to varying definitions of ‘healthy’ proportions of carbohydrate, protein, and fat. However, carbohydrate quality is increasingly regarded as important as the quantity of carbohydrate in a healthy diet.
A team of researchers summarized the available evidence that lifestyle changes can prevent diabetes in order to update the European Association for the Study of Diabetes clinical practice guidelines. The systematic review and meta-analysis included 7 randomized controlled trials. The trials offered a limited subset of lifestyle changes, namely better diet and increased physical activity. Overall, high-quality evidence showed that a better diet or increased physical activity reduced the risk of developing diabetes by 47 percent compared to the controls. Furthermore, the reduction in diabetes risk extended beyond the end of the active interventions, albeit with declining effectiveness over time. This finding suggests that diabetes prevention is not a ‘one-off’ proposition. Rather, preventing diabetes requires the sustained, long-term adoption of a healthy lifestyle, in particular a better diet and increased physical activity. Embracing additional healthy lifestyle choices, such as Sleep More and Better, Defuse Chronic Stress, and Live with Purpose would likely reduce the risk of diabetes even further and also reduce the risk of other chronic diseases.
What to do?
Type 2 diabetes is a huge, growing problem globally and in the US. Plus, complications of diabetes, including poor eyesight, kidney failure, and amputations, can imperil your quality of life. But here’s the great news: You can prevent type 2 diabetes by embracing healthy lifestyle choices, particularly Eat Better and Keep Moving. Why not start today by making one healthful change in your daily life?
