Healthy Lifestyle Can Delay Type 2 Diabetes Despite Genetic Risk

Genetics exert a powerful influence on the development of type 2 diabetes, although genes do not dictate every aspect of life.

New research indicates, for the first time, that people with a genetic predisposition to diabetes may still delay the condition by making appropriate lifestyle choices.

Type 2 diabetes, genetic risk and lifestyle changes

A 3-year intervention in Finland has found that a nutritious diet and regular physical activity can reduce the chance of type 2 diabetes developing in men with a high genetic risk.

The programme enabled participants to manage their blood sugar levels and lose weight. These benefits also applied to men considered to have low genetic risk factors for diabetes.

"These findings encourage everyone to make lifestyle changes that promote health. Furthermore, they demonstrate the effectiveness of group- and internet-based lifestyle guidance, which saves healthcare resources," says clinical nutritionist Maria Lankinen of the University of Eastern Finland.

This is not the first research to show that lifestyle interventions can lower the prevalence of type 2 diabetes.

More recently, a year-long diabetes programme in England showed that completely changing a person's everyday diet can place 32 percent of type 2 diabetes patients into remission, so they no longer require medication.

However, the latest research helps to clarify the respective contributions of genes and environment to the development of diabetes.

Finnish intervention study and participants

Researchers from the University of Eastern Finland and Kuopio University Hospital recruited more than 600 male participants aged over 50 for the intervention study.

Participants attended group sessions covering the value of a healthy diet and physical activity. Clinical nutritionists also provided personalised nutritional feedback, while participants received diet and exercise guidance for the next three years. During this period, they underwent an oral glucose tolerance test and a physical examination on two occasions.

Roughly half of those receiving the intervention had a high genetic risk for type 2 diabetes, with the remaining half having low genetic risk. Risk was calculated using a total of 76 gene variants known to raise the likelihood of type 2 diabetes.

A control group of 345 male participants did not receive the intervention. Of this group, 149 people had high genetic risk and 196 had low genetic risk.

Benefits for men at high and low genetic risk

Among participants with high genetic risk, those who completed the 3-year intervention were 6 percent less likely to subsequently develop type 2 diabetes than their counterparts with high genetic risk in the control group.

For intervention participants with low genetic risk, there was no significant difference compared with control-group participants at low genetic risk. Nevertheless, they experienced weight loss and metabolic improvements comparable to those seen in the high-risk intervention group.

For example, blood sugar control generally deteriorates as a person gets older, yet these harmful changes were significantly less pronounced in the intervention group than in the control group.

This indicates that people with low genetic risk can benefit from lifestyle changes as well.

Further research involving larger and more diverse cohorts is required to confirm the effect, but the researchers say the trial demonstrates that type 2 diabetes can be "prevented or delayed" through an accessible approach.

Prioritising a healthy diet and physical activity among middle-aged and older men, particularly those with a high genetic risk for type 2 diabetes, may offer a practical and cost-effective means of reducing the incidence of this very common metabolic disease.

"Therefore," the team from Finland concludes, "our results suggest that all individuals at risk of type 2 diabetes should be encouraged to make lifestyle changes regardless of genetic risk."

The study was published in the Journal of Clinical Endocrinology & Metabolism.