In a study of more than 500 000 Americans, those who ate a healthy diet reduced their risk for pancreatic cancer by 15%.
The diet used in the study followed federal dietary guidelines from 2005 and recommended eating a variety of nutritional foods and limiting saturated and trans fats, cholesterol, added sugars, salt and alcohol.
"Maintaining a healthful diet has many potential health benefits," said lead researcher Hannah Arem, from the division of cancer epidemiology and genetics at the US National Cancer Institute.
"Our study specifically suggests that individuals who reported dietary intakes in adherence with the federal dietary guidelines had a lower risk of pancreatic cancer," she said.
Arem said this finding shows only an association, and does not prove that eating a healthy diet prevented pancreatic cancer.
"The study was conducted in an observational cohort, meaning that we cannot draw conclusions about cause and effect," she said.
Arem also admitted that other things might explain the findings. "While we tested the influence of other characteristics and behaviours including education, smoking history, physical activity and vitamin use, in addition to other factors, the finding could be due to healthful behaviours other than diet that we did not query about on the questionnaire," she said.
The report was published in the 15 August issue of the Journal of the National Cancer Institute.
Elusive risk factors
"Identifying dietary risk factors for pancreatic cancer has been elusive," said Marji McCullough, strategic director of nutritional epidemiology at the American Cancer Society. "But following dietary patterns like these may not only reduce the risk of this fatal disease, but a host of other diseases."
McCullough added that it is important to focus on eating an overall healthful diet and not on a single nutrient, supplement or specific food in hopes of preventing cancer or any other disease.
"The effect of eating a variety of fruits, vegetables and whole grains, and limiting sugar, unhealthy fats and alcohol, is greater than the sum of its parts when it comes to lowering the risk of chronic disease," she said.
Pancreatic cancer is usually fatal and its incidence has been increasing, McCullough added. "It's very important to identify ways to prevent pancreatic cancer," she said.
Besides diet, there are other modifiable risk factors that increase the odds of pancreatic cancer, including obesity, type 2 diabetes, smoking and excessive alcohol consumption, McCullough said.
Another expert, Samantha Heller, senior clinical nutritionist at NYU Langone Medical Center in New York City, said that "by engaging in a healthy lifestyle, you can help block the cascade of ill health effects that is associated with poor food and lifestyle choices such as smoking and being sedentary."
"The body's physiology is complex and highly integrated, so we want to keep the entire organism healthy rather than focusing on trying to avoid one singular disease," Heller said.
For the study, Arem's group assessed the eating habits of more than 500 000 people, aged 50 to 71, who took part in the US National Institutes of Health/AARP Diet and Health Study.
They compared pancreatic cancer rates among those who were best at following the dietary guidelines with those who didn't adhere to the diet. In all, there were more than 2 300 cases of pancreatic cancer.
The researchers found that those who followed the diet lowered their chances of pancreatic cancer by 15%, compared with those who didn't.
The association was stronger in men who were overweight or obese, compared with normal-weight men, the researchers said. There was, however, no difference between normal-weight and overweight or obese women.
For more on pancreatic cancer, visit the American Cancer Society.