Review published in Advances in Nutrition finds “five statistically significant associations between dietary factors and pancreatic cancer risk.”

Due to its poor prognosis, pancreatic cancer led to almost as many deaths (⁓466,000) as the number of newly confirmed cases (⁓496,000) in 2020, making it the seventh leading cause of cancer death among both men and women worldwide, according to Global Cancer Statistics 2020.

Given that there are few early symptoms of pancreatic cancer, most pancreatic cancer patients first seek treatment at an advanced stage of the disease when treatment options are limited.  As a result, the survival rates for people with pancreatic cancer are poor, with the five-year survival rate approaching 10% for the first time in 2020 in the United States.

Unfortunately, the burden of pancreatic cancer is projected to increase significantly in the coming decades, partly due to a lack of established screening and early detection methods.  Identifying and understanding potentially modifiable lifestyle risk factors and establishing interventions to address these risk factors may therefore be the most effective way to reduce the burden of this disease until more effective treatments are developed.

In recent years, numerous studies have focused on the relationship between dietary factors and the risk of pancreatic cancer.  In 2018, for example, the World Cancer Research Fund and the American Institute for Cancer Research published their Third Expert Report: Diet, Nutrition, Physical Activity and Cancer: A Global Perspective, which included a chapter dedicated to pancreatic cancer.  Among their findings, the authors reported limited evidence linking a higher risk of pancreatic cancer with the consumption of red and processed meats, excessive alcohol, and foods and beverages containing fructose and saturated fatty acids.

The Third Expert Report analyzed data derived from prospective and retrospective studies published up until September 2011.  However, since that time, a considerable number of relevant meta-analyses (i.e., an examination of data from a number of independent studies researching the same topic in order to determine overall trends) have been published.  In response, the authors of Dietary Factors and Pancreatic Cancer Risk: An Umbrella Review of Meta-analyses of Prospective Observational Studies conducted a new review of these meta-analyses to assess and grade the evidence for the associations between 59 dietary factors and pancreatic cancer risk.  In contrast to the Third Expert Report, the authors worked exclusively with prospective studies, which are less prone to confounding than retrospective studies, to assess the strength of the evidence.  The results of their research were published in Advances in Nutrition, the international review journal of the American Society for Nutrition

Consistent with the Third Expert Report, the results of this review “highlight that regular nut consumption and reduced intake of fructose, red meat, and alcohol were associated with a lower risk of pancreatic cancer.”  In addition, the review found adherence to the Mediterranean diet was associated with a lower risk of pancreatic cancer.  Although the authors found five statistically significant associations between dietary factors and pancreatic cancer risk, “none of these was supported by convincing or highly suggestive evidence.”  The strongest evidence pointed towards a positive association between fructose intake and a higher pancreatic cancer risk.

Interestingly, despite finding “weak evidence” for a positive association between heavy alcohol intake and pancreatic cancer incidence, the authors found “no significant effect of low to moderate alcohol intake on pancreatic cancer risk.”

In conclusion, the authors have called for more research: “As some associations were rated as weak and most were considered nonsignificant, further prospective studies are needed to investigate the role of dietary factors and the risk of pancreatic cancer.”

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