Genetics play a very strong role in the development of type 2 diabetes, but genes don't determine everything in life.
A new study suggests for the first time that even those who are genetically predisposed to diabetes can hold off the disease with the right lifestyle choices.
A 3-year 'intervention' in Finland has now shown that a healthy diet and regular exercise can lower the likelihood of men developing type 2 diabetes who have 'high genetic risk'.
The program helped patients to balance their blood sugar and to lose weight, and this was true even for those deemed 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 isn't the first study to show that lifestyle interventions can reduce the prevalence of type 2 diabetes.
Just recently, a year-long diabetes program in England found that a total overhaul of a person's daily diet can put 32 percent of type 2 diabetes patients into remission, meaning they no longer need to be on medication.
This newest study does, however, help disentangle the roles that genes and the environment can play in the onset of diabetes.
Researchers at the University of Eastern Finland and Kuopio University Hospital in Finland included more than 600 male participants over the age of 50 in the intervention study.
These participants underwent group sessions on the importance of a healthy diet and physical activity. They were also given individual nutritional feedback by clinical nutritionists, and given a dietary and exercise guide for the following three years. An oral glucose tolerance test and a physical were performed twice during that time.
About half of the group included in the intervention had a high genetic risk for type 2 diabetes and the other half had a low genetic risk. This was scored on a sum of 76 gene variants known to increase the risk of type 2 diabetes.
A group of 345 male participants who did not undergo the intervention were included as a control group. This control group included 149 people with high genetic risk and 196 people with low genetic risk.
Compared to those with high genetic risk in the control group, those with high genetic risk who took part in the 3-year intervention were 6 percent less likely to go on to develop type 2 diabetes.
Those in the intervention group who had a low genetic risk did not show a significant difference to those with a low genetic risk in the control group, but they still showed weight loss and metabolic benefits on par with the high-risk intervention group.
As a person ages, for instance, their blood sugar control tends to worsen, but these adverse effects were significantly smaller in the intervention group compared to the control group.
This suggests that participants with a low genetic risk also benefit from the lifestyle changes.
More studies are needed to confirm this effect in larger and more diverse cohorts, but researchers argue this trial shows that type 2 diabetes can be "prevented or delayed" with an accessible approach.
Focusing on healthy diet and physical activity in middle-aged and elderly men, especially for those with a high genetic risk for type 2 diabetes, could be a cost-effective and practical way to reduce the occurrence of this highly 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.