Isoflavones from Phytoestrogens and Gastric Cancer Risk: A Nested Case-Control Study within the Korean Multicenter Cancer Cohort

Abstract

Background: The role of soybean products in gastric cancer risk is not clear in epidemiologic studies due to measurement error from dietary intake questionnaires and due to different degrees of bias according to study design. To examine the association between soybean products and gastric cancer risk, we measured phytoestrogen biological markers in a nested case-control study.Methods: The study population was composed of 131 cases and 393 matched controls within the Korean Multicenter Cancer Cohort. The concentrations of the four biomarkers in the plasma samples were measured using time-resolved fluoroimmunoassay. Conditional and unconditional logistic regression models were used to compute the odds ratio (OR) and 95% confidence intervals (CI).Results: Median plasma concentrations of genistein (229 nmol/L for controls, 181.8 nmol/L for cases; P = 0.07) and daidzein (131.2 nmol/L for controls, 80.5 nmol/L for cases; P = 0.04) in cases were lower than in controls, whereas equol concentrations were similar. Compared with the reference group, gastric cancer risk decreased in the highest groups for genistein (OR, 0.54; 95% CI, 0.31-0.93) and daidzein (OR, 0.21; 95% CI, 0.08-0.58). Higher equol concentrations were associated with a decreased risk for gastric cancer (OR, 0.50; 95% CI, 0.27-0.90). The combination of the highest concentrations for each isoflavone category was associated with a 0.09-fold decreased risk for gastric cancer compared with the combination of the lowest concentrations for each category. There was no association between plasma lignan concentrations and gastric cancer.Conclusions: High serum concentrations of isoflavones were associated with a decreased risk for gastric cancer. Impact: These results suggest a beneficial effect of high soybean product intake for gastric cancer risk.

Association Between HLA-DQ Genotypes and Haplotypes vs Helicobacter pylori Infection in an Indonesian Population

“…Dietary factors cannot be overlooked. Investigations on consumption of fresh fruit and vegetables, isoflavone-rich soybean products (Ko et al, 2010), such as tempe (fermented soybean curd) and vegetable oils, in particular, are now in progress. The present approaches are ecological studies using international groups/areas as units.…”

Isoflavones: Chemistry, Analysis, Functions and Effects on Health and Cancer

“…In Korean study, isoflavones including genistein, daidzein and equol have an effect for reducing gastric cancer risk, and the higher concentration of three isoflavones are, the much lower gastric cancer risk are (Ko et al, 2010). This protective effect for gastric cancer can be explained as an anti-inflammatory, anti-tumorogenic, and anti-oxidative effect of isoflavones.…”

The Soy Isoflavone Equol May Increase Cancer Malignancy via Up-regulation of Eukaryotic Protein Synthesis Initiation Factor eIF4G

“…Therefore, the association between equol production and cancer risk in humans remains to be adequately characterized (8,26,27). Overall, benefits from soy intake are associated with ER (ϩ) breast cancer, and the effect of equol or soy isoflavones on ER (Ϫ) breast cancers or established aggressive breast cancers are not well understood (5,28,29).…”