A major report on diabetes prevention suggests that healthy eating and regular exercise are much more effective at combating the disease than popular drug metformin.
Researchers studied 3,232 non-diabetic men and women with an average age of 51 years. All the participants were overweight and had significantly elevated blood sugar levels both after fasting and two hours following ingestion of a high sugar solution.
The subjects were randomly assigned to a placebo or control group, a group given 850mg of metformin twice daily or to a lifestyle intervention programme.
The study, published in the New England Journal of Medicine, revealed that a change in lifestyle for those at risk from diabetes helped cut that risk by 58 per cent compared to the control group.
Metformin, which is produced by pharmaceutical giant Bristol-Myers Squibb under the brand names Glucophage or Glucovance , was also shown to reduce the risk of diabetes, but only by 31 per cent. Dr William Knowler of the National Institute of Diabetes and Digestive and Kidney Diseases who led the research team said that the dietary and lifestyle changes did not need to be drastic to be effective in reducing diabetes risk.
He said that two-and-a-half hours of brisk walking each week and a seven per cent weight loss would produce significant benefits.
Dr Knowler's team did not say that that metformin was ineffectual at staving off diabetes - in fact they said it was a highly effective measure - but simply that "the lifestyle intervention was particularly effective". Dr Knowler also said it was unclear whether a combination of the lifestyle change and metformin would have produced even more positive results.
The researchers calculated that for every seven people at risk from diabetes who change their lifestyle, or every 14 people who regularly take metformin, one case of diabetes would be prevented every three years.
While the group taking more exercise suffered from a selection of related aches and pains, the metformin group reported slightly more serious side effects. Some 78 per cent of the volunteers in the drug group reported problems with diarrhoea, flatulence, nausea or vomiting, compared with just 31 per cent in the control group. Only 13 per cent of those in the lifestyle change group showed the same symptoms.