Developing type 2 diabetes can be a result of both genetics and lifestyle factors. While it is true that having a family history of diabetes increases a person’s diabetes risk,1 it has remained unclear whether positive lifestyle practices can truly “override” these chances. 

Now, a new study shows that a low-quality diet is linked to an increased risk, regardless of a person’s genetic risk.

Although there is data that suggests following a healthy diet and lifestyle is linked to a reduced type 2 diabetes risk, regardless of genetic risk factors, various limitations have made it difficult to definitively determine whether these interventions can truly impact diabetes risk.2

“Previous studies have shown that both genes and diet are associated with the risk of diabetes,” Jordi Merino, PhD, a research associate in the diabetes unit and center for genomic medicine, Massachusetts General Hospital and lead study author, told Verywell. “An intriguing and unanswered question was whether there is a synergic effect between genetic risk and diet.”

She explains that learning whether both factors play into each other would allow for specific dietary recommendations according to individual genetic susceptibility.

To determine whether genetic risk and diet quality impact the development of diabetes, researchers at Massachusetts General Hospital in Boston evaluated data from over 35,000 men and women in the United States.

The data used included available genetic data of those who were free from a diagnosis of diabetes, cardiovascular disease, or cancer at the beginning of data collection. The results were published in PLOS Medicine.

“Our findings provide new evidence on the lack of synergic effects, suggesting that everyone benefits from a healthy diet, regardless of their genetic susceptibility,” Merino explained.

Specifically, the results of this study suggested that, regardless of genetic risk, a low-quality diet was associated with a 30% increased risk of type 2 diabetes. The researchers documented “a risk gradient with increasing genetic risk and low diet quality, which suggests that individuals at increased genetic risk for diabetes might need to incorporate other lifestyle components in addition to a healthy diet to mitigate their inherited risk,” Merino added.

Ultimately, she suggested that these results “are essential to understanding why people develop diabetes and support evidence-based prevention strategies for type 2 diabetes.”

“While these results are compelling and they do add to the body of knowledge available to help people reduce their diabetes risk, it is important to remember that correlation does not necessarily mean causation,” Elizabeth Shaw, MS, RDN, a California-based registered dietitian and the owner of Shaw Simple Swaps, told Verywell. “It’s also important to remember there’s always room for error when self-reported dietary recalls are used as the base for these types of studies.”

However, Shaw does share that “these findings coincide with what many registered dietitian nutritionists, myself included, have been promoting for some time. Plus, these results deliver important information for providers to consider as a treatment for the primary prevention of type 2 diabetes.”

Emphasizing Diet Quality to Reduce Diabetes Risk

The authors of the study emphasize the importance of following a healthy, good quality diet.

According to the authors, what was considered to be high quality aligned with dietary practices found on the Alternate Healthy Eating Index. This score is based on 11 foods and nutrients, emphasizing a higher intake of fruits, whole grains, vegetables (excluding potatoes), nuts and legumes, polyunsaturated fatty acids, and long-chain fatty acids found in foods like fish and walnuts.

Other factors include a moderate intake of alcohol, and a lower intake of red and processed meats, sugar-sweetened drinks and fruit juice, sodium, and trans-fat. Stronger scores on this index appeared to result in reduced diabetes risk.

The Dietary Approaches to Stop Hypertension (DASH) score was used as another measure of diet quality, which includes information from eight foods and nutrients that have been shown to support healthy blood pressure. This includes a higher intake of fruits, whole grains, vegetables, nuts and legumes, and low-fat dairy products.

“It’s important to remember that high quality doesn’t mean expensive food or a restrictive lifestyle,” Mary Ellen Phipps, MPH, RDN, LD, a Texas-based registered dietitian and author of “The Easy Diabetes Desserts Cookbook,” told Verywell. “It means eating balanced meals filled with protein, fiber, and plant-based fats.”

Past data shows that following a Mediterranean-style, vegetarian, and a plant-based dietary pattern may result in reduced diabetes risk as well.3

“There is no one-size-fits-all diet that will reduce the risk of developing diabetes in all people,” Shaw shared. “Leaning on a registered dietitian to obtain an individualized nutrition plan should be explored if a person wants to eat in a way that can reduce their diabetes risk, regardless of their genetic predisposition.”