Meta-analysis of fish consumption and risk of pancreatic cancer in 13 prospective studies with 1.8 million participants

Abstract

A previous meta-analysis suggested no association between fish consumption and risk of pancreatic cancer. As several prospective studies with a large number of pancreatic cancer cases have emerged after that meta-analysis, we updated the evidence and examined the relationship in greater depth. We performed a literature search on PubMed and EMBASE databases through March 30, 2019 to identify potentially eligible studies. We used a random-effects model to compute summary relative risk (RR) with corresponding 95% confidence interval (CI). A total of 13 prospective studies comprising 4994 pancreatic cancer cases and 1,794,601 participants were included in the final analyses. Results of the meta-analysis showed that fish consumption was not significantly associated with risk of pancreatic cancer (RR 50-g/day = 1.03, 95% CI: 0.95–1.12), which was confirmed when stratifying the analysis by various methodological and population characteristics. There was a suggestion of difference by adjustment for family history of pancreatic cancer ( P difference = 0.05), with fish consumption being associated with higher risk of pancreatic cancer in studies without adjustment for participants’ family history (RR 50-g/day = 1.09, 95% CI: 1.02–1.18), and a non-significant inverse association among studies with the adjustment (RR 50-g/day = 0.93, 95% CI: 0.82–1.05). Results of this updated meta-analysis suggest that fish consumption is unlikely to be substantially associated with risk of pancreatic cancer.

Diets, Dietary Patterns, Single Foods and Pancreatic Cancer Risk: An Umbrella Review of Meta-Analyses

“…The reasons for exclusion are shown in Supplementary Table S2 . At the end of the screening process, 23 articles met the inclusion criteria and were included in the current review [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. All the included systematic reviews and meta-analyses only included original observational studies (case-control and/or cohort studies).…”

“…All the included articles were meta-analyses of observational studies (case-controls or cohort studies). Among the 23 articles included, 7 were studies assessing the association between dietary patterns and PC risk [ 35 , 39 , 40 , 43 , 48 , 52 , 56 ], whereas the remaining 16 studies analyzed the association between one or more dietary components and the risk of PC [ 36 , 37 , 38 , 41 , 42 , 44 , 45 , 46 , 47 , 49 , 50 , 51 , 53 , 54 , 55 , 57 ]. However, out of the 23 included articles, a total of 13 unique meta-analyses on dietary patterns and 29 unique meta-analyses on dietary components were detected because the articles reported the summary effect size separately by sex or study design.…”

“…The largest population (>1,000,000 subjects) was observed in meta-analyses on dietary components, such as total fruit [ 53 ] and citrus fruit [ 36 ], total vegetables [ 50 ] and cruciferous vegetable [ 47 ], red and processed meat [ 45 , 50 , 57 ], poultry [ 38 ] and fish [ 38 , 44 , 54 ]. On the other side, the smallest population was observed in a meta-analysis assessing the association between DII and PC risk ( n = 2408 subjects) [ 43 ].…”

“…No evidence was detected for the association between higher consumption of poultry, eggs, fish, and risk of PC, assessed by two [ 38 , 50 ], one [ 50 ], and five meta-analyses [ 38 , 44 , 50 , 51 , 54 ], respectively.…”

Diet, weight status, and physical activity in cancer prevention

“…Omega-6 fatty acids are converted by COX-2 enzyme into prostaglandin E2, a pro-inflammatory cytokine involved in the development of several cancers 62 , whereas omega-3 fatty acids compete against omega-6 fatty acids as a substrate for COX-2 enzyme resulting in the production of prostaglandin E3, which does not possess mutagenic properties 63 . Although high consumption of omega-3 fatty acids and low omega-6 fatty acids/omega-3 fatty acids ratio was found to be associated with a low risk of breast, ovarian, prostate, pancreatic, colorectal, and upper aero-digestive tract cancers 13,[64][65][66][67][68] , there is no enough evidence to suggest a significant relationship between the consumption of omega-3 fatty acids and cancer risk 69,70 . Despite the controversial findings of previous studies, there is some evidence that low-fat diets may reduce the incidence of some common cancers 16,20,71,72 .…”