Can diet alone control type 2 diabetes? No evidence yet

July 16, 2008

Despite strong evidence that type 2 diabetes can be prevented or at least delayed by a combination of lifestyle changes and good dietary advice, a team of Cochrane Researchers found that there is no indication whether dietary advice alone can prevent the disease.

Type 2 diabetes is very common and the number of people affected is increasing. The disease is linked to obesity, with 80% of individuals who develop the disease being obese. Therefore as the incidence of obesity rises around the world, so too does the incidence of type 2 diabetes. The World Health Organization (WHO) estimates that more than 180 million people worldwide have diabetes. It claims that this number is likely to more than double by 2030.

When a team of Cochrane Researchers set out to see if dietary advice alone could help a person with type 2 diabetes, they were only able to identify two trials that together involved just 358 people.

"Considering the importance of this disorder, we were disappointed to find such a small amount of relevant data," says lead researcher Lucie Nield, who works in Centre for Food, Physical Activity & Obesity, University of Teesside, Middlesbrough.

The two studies did, however, indicate that dietary advice alone could play an important role. One study randomly assigned people to either a control group or a dietary advice group. After six years 67.7% of people in the control group had diabetes, compared with only 43.8% in the advice group. This was a 33% reduction. In another study 12 months of dietary advice led to significant reductions in many diabetes related factors, such as insulin resistance, fasting C-peptide, fasting proinsulin, fasting blood glucose, fasting triglycerides, and fasting cholesterol and PAI-1.

"These two studies give grounds for believing that dietary advice alone could play an important role in reducing type 2 diabetes, but we do need more well-designed, long-term studies before we can work out the best advice to give," says Nield.

Source: Wiley