Diet quality linked to pancreatic cancer risk

In a large new study of older Americans, researchers find that people with the healthiest eating habits are about 15 percent less likely to develop pancreatic cancer than those with the poorest diets.

In the analysis of data on more than 500,000 Americans over age 50, men in particular, especially those who were overweight or obese, appeared to benefit most from a high quality diet.

"It is important to note that our findings are based on overall diet and not individual foods. A combination of many foods contributed to the observed association between greater compliance with the Dietary Guidelines and lower risk of pancreatic cancer," lead author Hannah Arem of the National Cancer Institute in Bethesda, Maryland, told Reuters Health in an email.

Though pancreatic cancer is rare - about 1.5 percent of Americans will develop the disease during their lifetimes - it is one of the most aggressive and lethal cancers. Only about six percent of people with pancreatic cancer are still alive five years after diagnosis, according to Arem.

Past studies looking at the relationship between diet and risk for pancreatic cancer have tended to focus on individual foods and found few connections, according to her team's report, published in the Journal of the National Cancer Institute.

To examine links between overall diet and cancer risk, Arem and her colleagues used the government-designed Healthy Eating Index published in 2005 (HEI-2005) as a basis for rating the overall quality of people's diets.

They applied those criteria to responses from 537,218 men and women who were part of the American Association for Retired Persons Diet and Health Study. Between 1995 and 1996, participants filled out diet questionnaires about how often they ate items on a list of 124 foods.

Arem's team then divided participants into five groups based on how closely their diets met HEI-2005 recommendations for consuming healthy foods such as fruits, vegetables and whole grains and limiting unhealthy ones, like red meat and junk foods.

Scores on the index range from 0 (no guidelines met) to 100 (all guidelines met), with high scores indicating the healthiest eating patterns.

Using state cancer registries and Social Security Administration data, the researchers followed participants for about 10 years and found that 2,383 people developed pancreatic cancer.

About 22 percent of the pancreatic cancer cases were among people with the lowest HEI-2005 scores, while 19 percent were in people with the highest scores. Overall, that translates to a 15 percent lower risk among those with the healthiest diets.

Among men who were overweight or obese, however, those with healthy eating scores in the top-fifth group were 28 percent less likely than their counterparts in the bottom-fifth to develop pancreatic cancer. The same effect was not seen among overweight women.