Pickled Vegetable and Salted Fish Intake and the Risk of Gastric Cancer: Two Prospective Cohort Studies and a Meta-Analysis

Abstract

An increased risk of gastric cancer for pickled vegetable and salted fish intake has been suggested, yet the lack of a dose-response association warrants a quantitative analysis. We conducted a meta-analysis, combining results from our analysis of two large Korean cohort studies and those from previous prospective cohort studies. We investigated the association of pickled vegetable and salted fish intake with gastric cancer in the Korean Genome Epidemiology Study and the Korean Multi-center Cancer Cohort Study using Cox proportional hazard models. We then searched for observational studies published until November 2019 and conducted both dose-response and categorical meta-analyses. The pooled relative risk (RR) of gastric cancer incidence was 1.15 (95% Confidence Interval (CI), 1.07–1.23) for 40 g/day increment in pickled vegetable intake in a dose-response manner (P for nonlinearity = 0.11). As for salted fish intake, the pooled risk of gastric cancer incidence was 1.17 (95% CI, 0.99–1.38) times higher, comparing the highest to the lowest intake. Our findings supported the evidence that high intake of pickled vegetable and salted fish is associated with elevated risk of gastric cancer incidence.

Prognostic Significance of ADAM17 for Gastric Cancer Survival: A Meta-Analysis

“…Some studies showed that biological and environmental factors, helicobacter pylori infection, excessive alcohol consumption, and smoking, can upregulate ADAM17 expression [ 39 , 40 , 41 , 42 , 43 ]. Helicobacter pylori infection may increase the incidence of gastric cancer and can increase the expression of ADAM17 in AGS gastric epithelial cells [ 44 ].…”

<p>Pickled Vegetables Intake Impacts the Metabolites for Gastric Cancer</p>

“…It has been reported that pickled vegetables intake increases the risk of gastric cancer, 3,6,7,19 but its molecular mechanism in gastric carcinogenesis remains unclear. Metabolomics is now moving beyond biomarkers and towards mechanisms.…”

“…Pickled vegetables were made with high concentrations of sodium chloride, which has been reported to induce mucosa and epithelial damage and produce chemical carcinogens-sodium nitrates and nitrites. 6 We speculate that long-term intake of pickled vegetables might affect the activity of metabolic enzymes in the folate metabolism pathway, which affected BH4 levels and BH4:BH2 ratio and perturbs the folate metabolism pathway, resulting in increased production of peroxynitrite and weakened T cell responses, which ultimately leads to tumor cell proliferation and immune escape. Then tumor cells are in a state of rapid proliferation and differentiation causing nucleotide synthesis and metabolism to be upregulated significantly.…”

“…34 11-trans-leukotriene C4 is the derivative of leukotriene, which is the major trigger of stressinduced oxidative DNA damage. 35 It is well known that pickled vegetables contain exogenous sources of sodium nitrates and nitrites, which can react with amino acids in the stomach and form N-nitro compounds, 6 resulting in oxidative damage. 16 However, the reduction of N-acetylmuramate (a microbial cell wall component) is catalyzed by N-acetylglucosamine kinase, turning it into N-acetylmuramate 6-phosphate.…”

“…Several studies have shown that pickled vegetable intake could increase the risk of GC. 4,6,7 It has been shown that the risk of GC for pickled vegetables intake is even higher than Helicobacter pylori (H. pylori) infection among Chinese populations (OR:1.49 [95% CI:1.10-2.01] vs 1.26 [95% CI: 1.12-1.62]). 8 Although several mechanisms have been postulated in epidemiological studies, [9][10][11] the molecular mechanism of pickled vegetable intake in gastric carcinogenesis remains unclear.…”