Can diet and exercise intervention prevent type 2 diabetes in individuals with a high genetic risk?

Previous studies have shown clear benefits of lifestyle intervention for the prevention of type 2 diabetes. Since then advances in gene technology have allowed researchers to identify more than 500 genetic variants that predispose individuals to type 2 diabetes. However, lifestyle factors are also important determinants of increased risk of developing type 2 diabetes. Whether type 2 diabetes can be prevented by lifestyle changes among individuals carrying numerous genetic variants that predispose them to type 2 diabetes however is not known. To clarify this, a new study from the University of Eastern Finland is the first to show that a healthy diet and regular exercise reduce the risk of type 2 diabetes even in individuals with a high genetic risk.¹

The T2D-GENE trial was a three-year lifestyle intervention that involved 973 men with the Metabolic Syndrome, aged 50–75 years, body mass index ≥25 kg/m², fasting plasma glucose 5.6–6.9 mmol/L and haemoglobin A1c < 48 mmol/mol. Genetic risk was determined based on 76 gene variants known to predispose to type 2 diabetes. There were 2 intervention groups, a low (n = 315) and high genetic risk for Type 2 Diabetes (n = 313), and the remaining participants served as a control group. Men in the intervention group were provided with a 3-year group-based intervention with access to a web portal focused on healthy diet and physical activity. The corresponding population-based control groups have low (n = 196) and high (n = 149) genetic risk for Type 2 Diabetes and received general health advice similar to the intervention group.

Men participating in the lifestyle intervention increased their intake of dietary fibre, improved the quality of fats in their diet and increased their consumption of vegetables, fruits and berries.

The intervention significantly lowered the risk of Type 2 Diabetes among the participants with a high genetic risk for T2D by 70%, whereas in the low genetic risk group the effect was not significant. The intervention effect was not significantly different between the high and low genetic risk groups (p = .135). The intervention significantly prevent the worsening of glucose levels and decreased weight both in the low and high genetic risk groups.

The study therefore was the first to show that individuals with a high genetic risk for T2D benefitted from a simple group-based intervention programme focusing on healthy diet and physical activity.