"The results suggest that carcinogenic substances related to meat preparation, rather than their inherent fat or cholesterol content, might be responsible for the association," said Ute Nöthlings, DrPH, MSE, the study's lead investigator from the Cancer Research Center at the University of Hawaii in Honolulu.
Meat consumption has been linked to pancreatic cancer in several case-control studies in the past, but the results have been inconsistent and data from prospective studies has been lacking.
For this study, researchers from the Cancer Research Center and USC examined the relationship of diet to pancreatic cancer among 190,545 men and women of African-American, Japanese-American, Caucasian, Latino and Native Hawaiian origin who were part of the Multiethnic Cohort Study in Hawaii and Los Angeles. An average follow-up of seven years yielded 482 incident cases of pancreatic cancer.
The researchers found that the heavy consumption of processed meats resulted in the highest risk for pancreatic cancer, after adjusting for age, smoking status, history of diabetes, familial history of pancreatic cancer and ethnicity. Those who consumed the greatest amount of processed meats had a 67 percent increase in risk over those participants with the lowest intake of this food category. A diet rich in pork and red meat also increased pancreatic cancer risk by about 50 percent, compared to their counterparts who ate less meat.
Consumption of poultry, fish, dairy products and eggs showed no link to pancreatic cancer risk, nor did overall intake of total fat, saturated fat, or cholesterol.
"An analysis of fat and saturated fat intakes showed a significant increase in risk for fats from meat, but not from dairy products, indicating that fat and saturated fat are not likely to contribute to the underlying carcinogenic mechanism," said Nöthlings.
In particular, the scientists suggest that chemical reactions that occur during the preparation of processed meats might be responsible for the association. Such reactions can yield carcinogens including heterocyclic amines or polycyclic aromatic hydrocarbons.
"Our study is the largest of its kind to demonstrate a link between high consumption of processed meats over long periods of time and pancreatic cancer," said Nöthlings. "The sample size allowed us to obtain statistically significant risk-estimates that support this hypothesis."
Founded in 1907, the American Association for Cancer Research is a professional society of more than 24,000 laboratory, translational, and clinical scientists engaged in all areas of cancer research in the United States and in more than 60 other countries. AACR's mission is to accelerate the prevention and cure of cancer through research, education, communication, and advocacy. Its principal activities include the publication of five major peer-reviewed scientific journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Epidemiology, Biomarkers & Prevention. AACR's Annual Meetings attract more than 15,000 participants who share new and significant discoveries in the cancer field. Specialty meetings, held throughout the year, focus on the latest developments in all areas of cancer research.