Jeonghee Lee

Dietary flavonoids and gastric cancer risk in a Korean population.

Gastric cancer is the most common cancer among men in Korea, and dietary factors are closely associated with gastric cancer risk. We performed a case-control study using 334 cases and 334 matched controls aged 35–75 years. Significant associations were observed in total dietary flavonoids and their subclasses, with the exception of anthocyanidins and isoflavones (OR (95% CI): 0.49 (0.31–0.76), p trend = 0.007 for total flavonoids). However, these associations were not significant after further adjustment for fruits and vegetable consumption (OR (95% CI): 0.62 (0.36–1.09), p trend = 0.458 for total flavonoids). Total flavonoids and their subclasses, except for isoflavones, were significantly associated with a reduced risk gastric cancer in women (OR (95% CI): 0.33 (0.15–0.73), p trend = 0.001 for total flavonoids) but not in men (OR (95% CI): 0.70 (0.39–1.24), p trend = 0.393 for total flavonoids). A significant inverse association with gastric cancer risk was observed in flavones, even after additional adjustment for fruits and vegetable consumption in women. No significantly different effects of flavonoids were observed between H. pylori-positive and negative subjects. In conclusion, dietary flavonoids were inversely associated with gastric cancer risk, and these protective effects of dietary flavonoids were prominent in women. No clear differences were observed in the subgroup analysis of H. pylori and smoking status.

Dietary Inflammatory Index and Risk of Colorectal Cancer: A Case-Control Study in Korea

The role of diet-associated inflammation in colorectal cancer is of interest. Accordingly, we aimed to examine whether the dietary inflammatory index (DII) was associated with the risk of colorectal cancer in a case-control study conducted in Korea. The DII was based on dietary intake, which was determined by a 106-item semi-quantitative food frequency questionnaire completed by 923 colorectal cancer cases and 1846 controls. Logistic regression was used to estimate odd ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were conducted by the anatomical site of the cancer, sex, and other risk factors. Higher DII scores were associated with an increased incidence of colorectal cancer (OR (95% CI) = 2.16 (1.71, 2.73) for highest vs. lowest tertile). The magnitude differed by anatomical site and sex. This association was slightly weaker in subjects with proximal colon cancer (1.68 (1.08, 2.61)) and was stronger in women (2.50 (1.64, 3.82)). Additionally, stronger associations were observed in subjects who were older than 50 years (p for interaction = 0.004) and engaged in physical activity (p for interaction < 0.001). Results from this study suggest that diet-associated inflammation may increase the risk of colorectal cancer, and this effect may differ by certain factors, such as anatomical site, age, sex, and lifestyle.

Dietary Patterns and Risk for Metabolic Syndrome in Korean Women: A Cross-Sectional Study

AbstractDietary patterns are a risk factor for metabolic syndrome (MetS). The prevalence of MetS has increased in Korea, and this condition has become a public health issue. Therefore, the present cross-sectional study aimed to identify the associations between dietary patterns and the risk of MetS among Korean women.The data of 5189 participants were analyzed to determine dietary intake and lifestyle. A principal components analysis was employed to determine participant dietary patterns with regard to 106 food items. MetS was diagnosed using the National Cholesterol Education Program, Adult Treatment Panel III. Logistic regression analyses were applied to evaluate the associations between dietary pattern quintiles and MetS and to generate odds ratios (ORs) and 95% confidence intervals (CIs) after adjusting for potential confounders.Three dietary patterns were identified: “traditional,” “western,” and “prudent.” The “prudent” dietary pattern consisted of a high intake of fruits and fruit products as well as nuts, dairy, and a low consumption of grains; this pattern was negatively associated with the risk of MetS. The highest quintile of the “prudent” dietary pattern was significantly less likely to develop MetS (OR: 0.5, 95% CI: 0.36–0.68, P for trend <0.001) compared with the lowest quintile. This pattern was also negatively associated with all of the MetS diagnostic criteria: abdominal obesity (OR: 0.52, 95% CI: 0.41–0.65), blood pressure (OR: 0.72, 95% CI: 0.59–0.87), triglycerides (OR: 0.67, 95% CI: 0.52–0.85), fasting glucose (OR: 0.64, 95% CI: 0.43–0.95), and high-density lipoprotein cholesterol (OR: 0.53, 95% CI: 0.42–0.68). However, the “traditional” and “western” dietary patterns were not associated with the risk of MetS.The “prudent” dietary pattern was negatively associated with the risk of developing MetS among Korean women.

Dietary patterns and colorectal cancer risk in a Korean population: A case-control study.

AbstractColorectal cancer (CRC) has been recognized as one of the major malignancies in Korea. Analyses of dietary patterns can provide insight into the complex interactions of foods, nutrients, and biologically active components within a diet, which vary among populations. We aimed to investigate the associations between dietary patterns and colorectal cancer risk in Koreans. In a study of 923 cases and 1846 controls, principal component analysis was used to identify dietary patterns based on 33 predefined food groups using a 106-item semiquantitative food frequency questionnaire (SQFFQ). The associations between dietary patterns and CRC risk were assessed using binary and polytomous logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Three dietary patterns (traditional, Westernized, and prudent) were derived. The proportion of total variation explained by 3 patterns was 24.2% for men and 25.3% for women. The traditional and prudent patterns were inversely associated with CRC risk [OR and 95% CI for the highest intake tertile of pattern score vs. the lowest = 0.35 (0.27–0.46) and 0.37 (0.28–0.48), respectively], whereas the Westernized pattern showed a positive association, especially among women [OR = 2.13 (1.35–3.34) for the highest tertile vs. the lowest]. A decrease in CRC risk among those with the highest intake of the prudent pattern was observed in all anatomical subsites in both men [OR = 0.36 (0.19–0.68) for proximal colon; 0.21 (0.12–0.36) for distal colon; 0.28 (0.18–0.44) for rectum] and women [OR = 0.28 (0.11–0.71); 0.27 (0.13–0.54); 0.45 (0.25–0.83)]. Our results indicate that individuals who prefer the Westernized dietary pattern should be made aware of their increased CRC risk. The traditional dietary pattern and the prudent pattern, which are rich in fruits and dairy products, are recommended for the Korean population to prevent CRC.

Isoflavone and Soyfood Intake and Colorectal Cancer Risk: A Case-Control Study in Korea.

We aimed to assess the relationship between dietary soyfood and isoflavone intake and colorectal cancer risk in a case-control study. A total of 901 colorectal cancer cases and 2669 controls were recruited at the National Cancer Center, Korea. A semi-quantitative food frequency questionnaire was used to assess the usual dietary habits, and the isoflavone intake level was estimated from five soyfood items. A high intake of total soy products, legumes, and sprouts was associated with a reduced risk for colorectal cancer in men and women, although the middle quartiles of intake of total soy products were associated with an elevated risk. In contrast, a high intake of fermented soy paste was associated with an elevated risk for colorectal cancer in men. The groups with the highest intake quartiles of isoflavones showed a decreased risk for colorectal cancer compared to their counterparts with the lowest intake quartiles in men (odds ratio (OR): 0.67, 95% confidence interval (CI): 0.51–0.89) and women (OR: 0.65, 95% CI: 0.43–0.99). The reduced risk for the highest intake groups persisted for distal colon cancer in men and rectal cancer in women. The association between soyfood intake and colorectal cancer risk was more prominent among post-menopausal women than pre-menopausal women. In conclusion, a high intake of total soy products or dietary isoflavones was associated with a reduced risk for overall colorectal cancer, and the association may be more relevant to distal colon or rectal cancers.

Dietary folate, one‐carbon metabolism‐related genes, and gastric cancer risk in Korea

SCOPE We evaluated the interactions between polymorphisms involved in one-carbon metabolism-related genes and dietary folate intake in gastric cancer risk within the Korean population through a hospital-based case-control study. METHODS AND RESULTS A total of 542 controls and 271 cases were included. Genotype data were selected from data produced by the Affymetrix Axiom(®) Exome 319 Array. We considered seven single nucleotide polymorphisms (SNPs) of five genes whose SNPs are located in the coding region with a minor allele frequency > 5%: MTHFR (G1793A, A1298C, C677T), MTR A2756G, MTRR A66G, SHMT1 C1420T, and SLC19A1 G80A. Our study found that MTR A2756G was associated with a decreased gastric cancer risk. MTHFR G1793A showed a statistically significant interaction between dietary folate intake and gastric cancer. CONCLUSION Our results suggest that MTR A2756G is significantly associated with gastric cancer risk, and that MTHFR G1793A statistically interacts with dietary folate intake. Our findings indicate that gene-folate interactions may contribute to gastric cancer risk.

Risk Factors for Thyroid Cancer: a Hospital-Based Case-Control Study in Korean Adults.

Purpose Although the incidence of thyroid cancer in Korea has rapidly increased over the past decade, few studies have investigated its risk factors. This study examined the risk factors for thyroid cancer in Korean adults. Materials and Methods The study design was a hospital-based case-control study. Between August 2002 and December 2011, a total of 802 thyroid cancer cases out of 34,211 patients screened from the Cancer Screenee. Cohort of the National Cancer Center in South Korea were included in the analysis. A total of 802 control cases were selected from the same cohort, and matched individually (1:1) by age (±2 years) and area of residence for control group 1 and additionally by sex for control group 2. Results Multivariate conditional logistic regression analysis using the control group 1 showed that females and those with a family history of thyroid cancer had an increased risk of thyroid cancer, whereas ever-smokers and those with a higher monthly household income had a decreased risk of thyroid cancer. On the other hand, the analysis using control group 2 showed that a family history of cancer and alcohol consumption were associated with a decreased risk of thyroid cancer, whereas higher body mass index (BMI) and family history of thyroid cancer were associated with an increased risk of thyroid cancer. Conclusion These findings suggest that females, those with a family history of thyroid cancer, those with a higher BMI, non-smokers, non-drinkers, and those with a lower monthly household income have an increased risk of developing thyroid cancer.

Genetic Variation in the TAS2R38 Bitter Taste Receptor and Gastric Cancer Risk in Koreans.

The human TAS2R38 gene encodes a bitter taste receptor that regulates the bitterness perception and differentiation of ingested nutritional/poisonous compounds in the oral cavity and gastrointestinal tract. TAS2R38 gene variants are associated with alterations in individual sensitivity to bitter taste and food intake; hence, these genetic variants may modify the risk for diet-related diseases, including cancer. However, little is known about the association between TAS2R38 polymorphisms and gastric cancer susceptibility. The present case-control study examined the influence of TAS2R38 polymorphisms on food intake and determined whether they predict gastric cancer risk in Koreans. A total of 1,580 subjects, including 449 gastric cancer cases, were genotyped for TAS2R38 A49P, V262A, I296V and diplotypes. Dietary data were analysed to determine the total consumption of energy, fibre, vegetables, fruits, sweets, fats, alcohol and cigarettes. TAS2R38 diplotype was not associated with food, alcohol or cigarette consumption, either independent or dependent of gastric cancer phenotype. However, the PAV/AVI diplotype significantly increased gastric cancer risk (adjusted odds ratio: 1.513; 95% confidence interval: 1.148–1.994) independent of dietary intake. Findings suggest that TAS2R38 may be associated with the risk for gastric cancer in Koreans, although the TAS2R38 diplotype did not influence dietary intake.

Dietary Flavonoids, CYP1A1 Genetic Variants, and the Risk of Colorectal Cancer in a Korean population

The role of dietary flavonoid intake in colorectal carcinogenesis might differ according to flavonoid subclasses and individual genetic variants related to carcinogen metabolism. Therefore, we examined whether greater dietary intake of flavonoid subclasses was associated with a lower risk of colorectal cancer and whether CYP1A1 genetic variants altered this association. A semi-quantitative food frequency questionnaire was used to assess the dietary intake of six flavonoid subclasses (flavonols, flavones, flavanones, flavan-3-ols, anthocyanidins, and isoflavones) in 923 patients with colorectal cancer and 1,846 controls; furthermore, CYP1A1 genetic variants (rs4646903 and rs1048943) were genotyped. Among the subclasses of flavonoids, higher intake of flavonols and flavan-3-ols showed a stronger association with a reduced risk of colorectal cancer after adjusting for potential confounding factors. Carriers of the CYP1A1 rs4646903 CC homozygous variant showed a reduced risk of rectal cancer compared with that in TT carriers. The inverse association between dietary flavonol intake and colorectal cancer risk was stronger among carriers of the CC homozygous variant than among T allele carriers (P for interaction = 0.02), particularly for rectal cancer (P for interaction = 0.005). In conclusion, the effect of dietary flavonoid intake on colorectal cancer risk differs according to flavonoid subclasses and CYP1A1 genetic variants.

Diabetes Mellitus and Site-specific Colorectal Cancer Risk in Korea: A Case-control Study

Objectives: Previous large-scale cohort studies conducted in Korea have found a positive association between diabetes mellitus (DM) and colorectal cancer (CRC) in men only, in contrast to studies of other populations that have found significant associations in both men and women. Methods: A total of 1070 CRC cases and 2775 controls were recruited from the National Cancer Center, Korea between August 2010 and June 2013. Self-reported DM history and the duration of DM were compared between cases and controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by binary and polytomous logistic regression models. Results: DM was associated with an elevated risk of CRC in both men (OR, 1.47; 95% CI, 1.13 to 1.90) and women (OR, 1.92; 95% CI, 1.24 to 2.98). This association remained when we controlled for age, body mass index, alcohol consumption, and physical activity level. In sub-site analyses, DM was associated with distal colon cancer risk in both men (multivariate OR, 2.04; 95% CI, 1.39 to 3.00) and women (multivariate ORs, 1.99; 95% CI, 1.05 to 3.79), while DM was only associated with rectal cancer risk in women (multivariate OR, 2.05; 95% CI, 1.10 to 3.82). No significant association was found between DM and proximal colon cancer risk in either men (multivariate OR, 1.45; 95% CI, 0.88 to 2.41) or women (multivariate OR, 1.79; 95% CI, 0.78 to 4.08). Conclusions: Overall, DM was associated with an increased risk of CRC in Koreans. However, potential over-estimation of the ORs should be considered due to potential biases from the case-control design.