Low-fat diets and half an hour of exercise each day slash the risk of developing diabetes by 58 percent among people at high risk, according to a nationwide study. The research also shows that, as an alternative, a drug used to treat diabetes reduces the risk of the disease by 31 percent.
All 3,234 participants in the trial were overweight and had trouble controlling concentrations of sugar in their blood. This condition often leads to type II, or adult-onset, diabetes. The researchers offered one-third of the volunteers regular, individualized counseling about diet and exercise, as well as cooking and gym classes. Another third took the diabetes drug metformin, and the remaining third took dummy pills. Doctors also provided general information on diet and exercise to the metformin and dummy-pill groups. People in the lifestyle-change group lost, on average, about 15 pounds over 3 years of the study.
Each year, 11 percent of participants taking the dummy pills developed diabetes. In contrast, annually 7.8 percent of those taking metformin and just 4.8 percent of those getting counseling and classes developed diabetes. Because of these striking results, the National Institutes of Health in Bethesda, Md., stopped its study a year early and announced the findings this month.
“Diabetes is not inevitable,” says Robert E. Ratner of the MedStar Research Institute in Washington, D.C., one of the lead investigators. “Lifestyle modification is achievable and changes health outcomes . . . . Those individuals who can’t sustain lifestyle modifications now have a choice [in metformin] that is significantly better than nothing.”
The study doesn’t prove that these interventions will permanently prevent diabetes, says Ratner, but even delaying the onset of the disease could stave off many cases of painful and costly complications like blindness and kidney failure. About 10 million people in the United States have blood concentrations of sugar as high as those of the participants in this study.
The researchers plan to study whether metformin and counseling combined are even more effective than either alone. They’ll also continue to follow people in the current study to see whether the treatments lower their incidence of heart disease.