Over half of Type 2 diabetes cases could be preventable, UMass Amherst-led study suggests
A new study led by researchers at the University of Massachusetts Amherst suggests that even people with a high genetic risk for Type 2 diabetes can substantially reduce their chances of developing the disease by adopting healthier lifestyles-and that more than half of cases might be preventable.
Published in the journal Diabetes, the study analyzed data from more than 332,000 adults in the U.K. and found that lifestyle factors such as body weight, physical activity, smoking and diet play a powerful role in shaping diabetes risk, regardless of genetic predisposition.
“Even if you have a strong family history or high genetic risk, it’s not a foregone conclusion that you’ll develop Type 2 diabetes,” says senior author Cassandra Spracklen, associate professor of epidemiology at UMass Amherst. “Healthier lifestyle choices will mitigate your risk-even if you’ve lost the genetic lottery.”
The study examined how genetic risk, which was calculated using 783 known diabetes-related genetic variants, interacts with lifestyle behaviors. Participants were followed for a median of nearly 14 years, during which 4% developed Type 2 diabetes.
Both genetic risk and lifestyle independently can increase the likelihood of developing the disease. But lifestyle had the stronger effect. Individuals with the least healthy lifestyles were nearly seven times more likely to develop diabetes than those with the healthiest habits, compared to a 2.6-fold increased risk for those with the largest genetic risk for Type 2 diabetes versus those with the lowest genetic risk.
“As these findings show, while genetic predisposition plays an important role, lifestyle choices have a substantially larger impact on diabetes risk,” adds Chi “Josh” Zhao, a doctoral student in epidemiology at UMass Amherst and first author of the study. “Encouragingly, this means that individuals can meaningfully reduce their risk through healthier behaviors, regardless of their genetic background.”
When looking at the combined effect of lifestyle choices and genetics, across all levels of genetic risk, people who maintained healthier lifestyles consistently had lower rates of diabetes than those with poorer habits.
In fact, the analysis suggests that more than 55% of new Type 2 diabetes cases could theoretically be prevented if people with less healthy lifestyles improved those behaviors.
Researchers classified lifestyle using four factors based on American Heart Association guidelines: smoking status, body mass index (BMI), physical activity and diet. People with at least three healthy factors were categorized as having a healthy lifestyle.
Among those factors, BMI had the strongest association with diabetes risk, followed by smoking and physical activity. Diet still mattered, but had the smallest independent effect in this analysis.
The results were consistent across men and women and across multiple ancestry groups, suggesting the findings are broadly applicable.
Participants ranged in age from 40 to 69 at enrollment, and the study tracked their health outcomes for up to two decades using the UK Biobank, a large-scale biomedical database.
The research adds to growing evidence that while genetics contribute to disease risk, modifiable behaviors play a critical role.
“You cannot change your genetics,” Spracklen notes. “But even making improvements as an adult-not necessarily perfect changes, but better ones-can still reduce risk.”
She adds that delaying the onset of diabetes, even if it is not fully prevented, could reduce long-term complications associated with the disease.
Reference:
Chi Zhao, Konstantinos Hatzikotoulas, Raji Balasubramanian, Elizabeth Bertone-Johnson, Na Cai, Lianyun Huang, Alicia Huerta-Chagoya, Margaret Janiczek, Chaoran Ma, Ravi Mandla, Amanda Paluch, Nigel W. Rayner, Lorraine Southam, Susan R. Sturgeon, Ken Suzuki, Henry J. Taylor, Nicole Vankim, Xianyong Yin, Chi Hyun Lee, Francis Collins, Cassandra N. Spracklen; Associations of Combined Genetic and Lifestyle Risks With Incident Type 2 Diabetes in the UK Biobank. Diabetes 20 April 2026; 75 (5): 860–866.
