Family history can make type 2 diabetes feel almost inevitable. A new study suggests the story may be more hopeful, but not as simple as “just make better choices.”
Researchers led by the University of Massachusetts Amherst found that healthier lifestyle patterns were linked to lower type 2 diabetes risk, even among people with higher genetic risk for the disease. The study, published in Diabetes, analyzed data from more than 332,000 adults in the UK Biobank and followed them for a median of nearly 14 years.
The researchers estimated genetic risk using 783 known diabetes-related genetic variants. They also created a lifestyle score based on four factors: smoking status, BMI, physical activity and diet. Participants with at least three healthy factors were classified as having a healthy lifestyle.
During the follow-up period, about 4% of participants developed type 2 diabetes. Both genetic risk and lifestyle patterns were linked to diabetes risk, but lifestyle showed the stronger association. People with the least healthy lifestyles were nearly seven times more likely to develop type 2 diabetes than those with the healthiest lifestyles, while those with the highest genetic risk had about 2.6 times the risk of those with the lowest genetic risk, according to the university release and study abstract.
“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,” said Cassandra Spracklen, senior author of the study and associate professor of epidemiology at UMass Amherst. “Healthier lifestyle choices will mitigate your risk — even if you’ve lost the genetic lottery.”
That message is important because genetic risk can feel discouraging. If a parent, grandparent or sibling has type 2 diabetes, it can be easy to assume the same diagnosis is only a matter of time. This study adds to evidence that risk is shaped by both inherited biology and modifiable factors.
But the word “lifestyle” needs some care. In this study, lifestyle included diet, physical activity and smoking status, but it also included BMI. BMI is a body-size measure, not a daily behavior. It can reflect many influences, including genetics, medications, health conditions, income, stress, sleep, food access, work schedules and neighborhood environment.
That means the findings should not be used to blame people for developing type 2 diabetes. Instead, they point to a broader idea: patterns that support metabolic health may lower risk, even when inherited risk is higher.
The study found that across all genetic risk groups, people with healthier lifestyle profiles had lower rates of type 2 diabetes than people with less healthy profiles. The researchers also estimated that more than 55% of new type 2 diabetes cases could theoretically be prevented if people with less healthy lifestyles improved those factors.
That estimate is a population-level calculation. It does not mean every individual case can be prevented, and it does not mean everyone has equal ability to change the conditions that shape health. Food prices, safe places to exercise, time, caregiving demands, medical care and chronic stress can all affect whether healthy changes are realistic.
The study’s diet measure also deserves context. Among the four lifestyle factors, BMI had the strongest association with diabetes risk, followed by smoking and physical activity. Diet still mattered, but it had the smallest independent association in this analysis.
That does not mean diet is unimportant. Diet can affect blood sugar, weight, insulin sensitivity and overall metabolic health. But it does mean that type 2 diabetes risk is not explained by diet alone.
The study has several strengths. It included a large number of participants, used genetic data and followed people over time. The results were also consistent across men and women and across multiple ancestry groups, according to UMass Amherst.
Still, this was an observational study. It can show that healthier lifestyle patterns were linked to lower diabetes risk, but it cannot prove that changing any one factor would prevent diabetes for a specific person. The UK Biobank also includes volunteers who may differ from the general population in ways that affect health risk.
The practical takeaway is not that genes do not matter. They do. But they are not the whole story.
“You cannot change your genetics,” Spracklen said. “But even making improvements as an adult — not necessarily perfect changes, but better ones — can still reduce risk.”
For people worried about type 2 diabetes, that may be the most useful part of the study. Prevention does not have to mean perfection. It may mean working with a health care provider to understand personal risk, checking blood sugar when appropriate, building meals around more fiber-rich foods, finding realistic ways to move more, getting support to stop smoking or making small changes that can be sustained over time.
Delaying type 2 diabetes can also matter. Even when the disease is not fully prevented, later onset may reduce the years a person lives with elevated blood sugar and the complications that can follow.
Genetics may load the dice, but this study suggests they do not make the outcome automatic.
The study was supported by the American Diabetes Association, the National Institutes of Health and the Commonwealth of Massachusetts.