Dietary factors and stomach cancer: a case-control study in Korea

Soy Product Consumption and the Risk of Cancer: A Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND

The association between soy product consumption and cancer risk varies among studies. Therefore, this comprehensive meta-analysis of observational studies examines the association between soy product consumption and total cancer risk.

METHODS

This study was conducted following the PRISMA guidelines. Up to October 2023, all eligible published studies were searched through PubMed and Web of Science databases.

RESULTS

A total of 52 studies on soy product consumption were included in this meta-analysis (17 cohort studies and 35 case-control studies). High consumption of total soy products (RR: 0.69; 95% CI: 0.60, 0.80), tofu (RR: 0.78; 95% CI: 0.70, 0.86), and soymilk (RR: 0.75; 95% CI: 0.60, 0.93) were associated with reduced total cancer risk. No association was found between high consumption of fermented soy products (RR: 1.18; 95% CI: 0.95, 1.47), non-fermented soy products (RR: 0.95; 95% CI: 0.77, 1.18), soy paste (RR: 1.00; 95% CI: 0.88, 1.14), miso soup (RR: 0.99; 95% CI: 0.87, 1.12), or natto (RR: 0.96; 95% CI: 0.82, 1.11) and cancer risk. A 54 g per day increment of total soy products reduced cancer risk by 11%, a 61 g per day increment of tofu reduced cancer risk by 12%, and a 23 g per day increment of soymilk reduced cancer risk by 28%, while none of the other soy products were associated with cancer risk.

CONCLUSION

Our findings suggest that high total soy product consumption, especially soymilk and tofu, is associated with lower cancer risk. More prospective cohort studies are still needed to confirm the causal relationship between soy product consumption and cancer risk.

Association of Fried Food Intake with Gastric Cancer Risk: A Systemic Review and Meta-Analysis of Case-Control Studies

Gastric cancer is one of the most prevalent cancers in Asia, and has a significant global incidence. However, the impact of fried food consumption on gastric cancer risk remains uncertain, mainly due to the limited number of participants in previous studies. To address this knowledge gap, we aimed to examine the association between fried food intake and gastric cancer incidence through a comprehensive meta-analysis. We conducted a thorough search across multiple databases, including PubMed, EMBASE, Google Scholar, Cochrane Library, China National Knowledge Infrastructure (CNKI), Korean Information Service System (KISS), and Research Information Service System (RISS), to collect studies. The newly analyzed results of the Korean Genome and Epidemiology Study (KoGES) findings were added. We assessed integrated odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) from the selected studies using Cochrane RevMan 5.0 for the meta-analysis. The quality of the studies included in the meta-analysis was assessed using the Study Quality Assessment Tool of the National Heart, Lung, and Blood Institute (NHLBI). We included 18 studies in the analysis, which compared the impact of fried food intake in gastric cancer patients (n = 5739) and healthy adults (control, n = 70,933). There was a significant positive association between gastric cancer risk and fried food intake (OR = 1.52, 95% CI = 1.23-1.87, I2 = 76%, p = 0.0001). The relationship was found to be significant in both non-East Asians (OR = 1.48, 95% CI = 1.18-1.85, I2 = 31%, p = 0.0006) and East Asians (OR = 1.54, 95% CI = 1.14-2.08, I2 = 83%, p = 0.005). In conclusion, this meta-analysis supports the notion that fried food intake is associated with an increased risk of gastric cancer in both non-Asians and Asians. Promoting a reduction in fried food consumption as a measure against gastric cancer risk is recommended.

Association between chili pepper consumption and risk of gastrointestinal-tract cancers: A meta-analysis

Background

Stimulating food is emerging as an important modifiable factor in the development of gastrointestinal (GI) tract cancers, but the association between chili pepper consumption and the risk of GI cancers is unclear. We aimed to evaluate the direction and magnitude of the association between chili pepper consumption and the risk of GI cancers.

Methods

A literature search was performed in PubMed, Embase, and Web of Science databases from inception to 22 December 2021. Observational studies reporting the association between chili pepper consumption and the risk of gastric cancer (GC), esophageal cancer (EC), and/or colorectal cancer (CRC) in adults were eligible for inclusion. Data extraction and quality assessment were conducted independently by two reviewers for the included literature. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Subgroup analyses were also performed based on the cancer type, study design, region of the study, study quality, and adjustments.

Results

A total of 11,421 studies were screened, and 14 case-control studies were included involving 5009 GI cancers among 11,310 participants. The summary OR showed that high consumption of chili pepper was positively related to the risk of GI cancers (OR = 1.64; 95% CI: 1.00–2.70). A stronger positive relationship was observed between chili pepper consumption and EC risk (OR = 2.71; 95% CI: 1.54–4.75), but there was no statistically significant association between GC and CRC risk. In analyses stratified by geographical location, a positive association was found between chili pepper consumption and the risk of GI cancers in Asian studies (OR = 2.50; 95% CI: 1.23–5.08), African studies (OR = 1.62; 95% CI: 1.04–2.52), and North American studies (OR = 2.61; 95% CI: 1.34–5.08), but an inverse association was seen in South American studies (OR = 0.50; 95% CI: 0.29–0.87) and European studies (OR = 0.30; 95% CI: 0.15–0.61).

Conclusion

This meta-analysis suggests that chili pepper is a risk factor for certain GI cancers (e.g., EC). Geographical regions influence the risk of GI cancers, especially in Asian, African, and North American populations, which require more attention during dietary guidance.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022320670].

Effect of Dietary Salt Intake on Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Case-Control Studies

Aim: The effect of dietary salt intake on the risk of gastric cancer is not clear. A meta-analysis was performed to estimate the association between dietary salt intake and the risk of gastric cancer. Methods: Three major databases were searched to retrieve case-control studies published in English before 1 July 2022. Random effects model analysis was used to obtain the pooled odds ratios (ORs) and 95% confidence intervals (CIs) of the association between dietary salt intake and risk of gastric cancer. Subgroup analyses were used to identify possible sources of heterogeneity. Results: Thirty-eight case-control studies were included in this meta-analysis (total population: n = 37,225). The pooled ORs showed a significantly positive association between high salt intake and gastric cancer compared with low salt intake (OR = 1.55, 95% CI (1.45, 1.64); p < 0.001). In subgroup meta-analysis for geographic region, estimation method for dietary salt intake and the source of controls, this association was not changed. Conclusion: Higher dietary salt intake increased the risk of gastric cancer. This study has implications for the prevention of gastric cancer.

Cruciferous vegetable consumption and multiple health outcomes: an umbrella review of 41 systematic reviews and meta-analyses of 303 observational studies

Background: Epidemiological studies evaluating the associations between the consumption of cruciferous vegetables (CV) and diverse health outcomes have generated inconsistent findings. Therefore, we carried out an umbrella review to systematically summarize existing evidence on this topic. Methods: This study had been registered at PROSPERO (no. CRD42021262011). Relevant systematic reviews and meta-analyses of observational studies were identified by searching PubMed, Web of science, and Embase databases from inception up to March 15, 2021. Observational studies investigating the association between CV intake and multiple health outcomes in humans were eligible for inclusion. The validated AMSTAR (A Measurement Tool to Assess Systematic Reviews) instrument was utilized for assessing the methodological quality of the included systematic reviews. For each meta-analysis, we assessed the summary effect size by using fixed and random effects models, 95% prediction intervals, heterogeneity, evidence of small-study effects, and excess significance bias. Results: Our umbrella review included 41 meta-analyses of 303 individual studies involving 13 394 722 participants. Twenty-four health outcomes including cancers (n = 23), cardiovascular disease (n = 12), mortality (n = 5), and metabolic diseases (n = 1) were evaluated. The summary random effects estimates were significant at P < 0.05 in 24 meta-analyses - all of which reported decreased risks of health outcomes. All were of moderate methodological quality in our study. Of the 41 meta-analyses, we observed suggestive evidence for beneficial associations between gastric cancer, lung cancer, endometrial cancer, and all-cause mortality. Moreover, 16 associations were supported by weak evidence, including breast cancer, lung cancer, renal cell carcinoma, bladder cancer, prostate cancer, ovarian cancer, endometrial cancer, colon cancer, colorectal adenoma, colorectal neoplasm, non-Hodgkin lymphoma, and total cancer. Conclusions: It revealed that CV intake might be associated with beneficial effects on several health-related outcomes (gastric cancer, lung cancer, endometrial cancer, and all-cause mortality). Other associations could be genuine, but substantial uncertainty remains. Additional studies are needed to evaluate the relationship between the consumption of CV and various health outcomes as well as robust randomized controlled trials in the future.

The association between soy-based food and soy isoflavone intake and the risk of gastric cancer: a systematic review and meta-analysis

Soy contains many bioactive phytochemicals, such as isoflavones, which have the effect of preventing many cancers. Some studies have shown the beneficial effect of soy-based food and isoflavone intake on gastric cancer (GC), while others claimed no effect. Therefore, whether the beneficial effect of soy-based food is related to its fermentation or whether its protective effect comes from isoflavones still remains inconclusive. Our aim was to investigate the relationship between total soybean, fermented soybean, non-fermented soybean and isoflavone intake, and the risk of GC. Ten cohort studies and 21 case-control studies involving 916 354 participants were included. The association between soy-based food and isoflavone intake and the risk of GC was calculated with the pooled relative risks (RRs) for the highest versus lowest intake categories. The results showed that isoflavone intake might be a protective factor to GC, but the result was not statistically significant (RR = 0.92; 95% CI: 0.79-1.07). However, total soybean intake could significantly decrease the risk of GC by 36% (RR = 0.64; 95% CI: 0.51-0.80), which might be credited to non-fermented soybean products (RR = 0.79; 95% CI: 0.71-0.87). In contrast, high intake of fermented soybean products could increase the risk of GC (RR = 1.19; 95% CI: 1.02-1.38). High intake of total soybean and non-fermented soybean products could reduce the risk of GC, and high intake of fermented soybean products could increase the risk, which indicated that the beneficial effect of soy-based food might be related to its non-fermentation. However, high intake of isoflavones may not be associated with the incidence of GC. © 2021 Society of Chemical Industry.

Dietary Pattern, Genomic Stability and Relative Cancer Risk in Asian Food Landscape

The incidence of cancer globally is increasing, partly due to lifestyle factors. Despite a better understanding of cancer biology and advancement in cancer management and therapies, current strategies in cancer treatment remain costly and cause socioeconomic burden especially in Asian countries. Hence, instead of putting more efforts in searches for new cancer cures, attention has now shifted to understanding how to mitigate cancer risk by modulating lifestyle factors. It has been established that carcinogenesis is multifactorial, and the important detrimental role of oxidative stress, chronic inflammation, and genomic instability is evident. To date, there is no study linking dietary pattern and genomic stability in cancer risk in the Asian food landscape. Thus, this present review article discusses recent literature on dietary pattern and genomic stability and its relationship with cancer risk in Asia.

Gastric Cancer and the Daily Intake of the Major Dish Groups Contributing to Sodium Intake: A Case-Control Study in Korea

Studies on the association between gastric cancer (GC) and the intake of soup-based dish groups (noodles and dumplings, soups, and stews), which are sodium-contributing foods, in Korea are insufficient, and the results of studies on the intake of pickled vegetables such as kimchi are inconsistent. This study aimed to determine the association between the incidence of GC and the daily intake of high-sodium dish groups (noodles and dumplings, soups, stews, and pickled vegetables) and whether these associations differ depending on behavioral risk factors for GC. In this case-control study, subjects aged 20–79 years were recruited from two hospitals between December 2002 and September 2006. A total of 440 cases and 485 controls were recruited, of which 307 pairs were matched and included for the analysis. In our results, a higher intake of noodles and dumplings was associated with a significantly increased incidence of GC. In the participants who consumed past or current alcohol, a higher intake of noodles and dumplings was associated with a significantly increased incidence of GC. Our results suggest that efforts to reduce the daily sodium intake from noodles and dumplings are needed to prevent and reduce the incidence of GC.

Spicy food consumption and risk of gastrointestinal-tract cancers: findings from the China Kadoorie Biobank

BACKGROUND

Previous case-control studies have reported positive associations of spicy food consumption with risks of certain gastrointestinal-tract (GI) cancers. However, there is no prospective evidence on such associations, particularly from China, where there are high incidence rates of GI cancers and spicy food is widely consumed.

METHODS

The prospective China Kadoorie Biobank study recruited >512 000 adults aged 30-79 years from 10 areas in China during 2004-2008; 2350 oesophageal, 3350 stomach and 3061 colorectal incident cancer cases were recorded by 1 January 2017, after a median of 10.1 years of follow-up. Cox regression yielded adjusted hazard ratios (HRs) for each cancer associated with spicy food intake.

RESULTS

Overall, 30% of participants reported daily spicy food consumption at baseline. Spicy food consumption was inversely associated with oesophageal cancer risk, with adjusted HRs of 1.00, 0.88, 0.76, 0.84 and 0.81 for those who never/rarely consumed (reference) and consumed monthly, 1-2 days/week, 3-5 days/week and 6-7 days/week, respectively (ptrend < 0.002). The association remained similar after excluding the first 3 years of follow-up but appeared stronger in participants who did not smoke or drink alcohol regularly (ptrend < 0.0001). The corresponding HRs for stomach cancer were 1.00, 0.97, 0.95, 0.92 and 0.89 (ptrend = 0.04), with the association disappearing after excluding the first 3 years of follow-up. For colorectal cancer, the HRs were 1.00, 1.00, 0.95, 0.87 and 0.90, respectively (ptrend = 0.04) and the inverse association appeared to be restricted to rectal rather than colon cancer (pheterogeneity = 0.004). The types and strength of spice used showed little additional effects on these associations.

CONCLUSION

In Chinese adults, higher spicy food consumption was associated with lower risks of certain GI cancers, particularly among individuals who never smoked or drank alcohol regularly.

Alcohol consumption and risk of stomach cancer: A meta-analysis

Stomach cancer is one of the most common cancers in the world. The relationship between alcohol consumption and the risk of stomach cancer remains unclear. Epidemiology studies investigating this relationship have shown inconsistent findings. A meta-analysis was performed to explore the association between alcohol consumption and increased stomach cancer risk. Eighty-one epidemiology studies, including 68 case-control studies and 13 cohort studies, were included in this study. A significant association was found between alcohol consumption and increased risk of stomach cancer (OR = 1.20, 95% CI 1.12-1.27). To explore the source of the significant heterogeneity (p < 0.05, I² = 86%), analysis was stratified by study type (case-control study and cohort study), control type (hospital-based control and population-based control), gender (male, female, and mix), race (White and Asian), region (United States, Sweden, China, Japan), subsite of stomach cancer, and type of alcohol. The stratified analyses found that region and cancer subsite are major sources of the high heterogeneity. The inconsistent results in different regions and different subsites might be related to smoking rates, Helicobacter pylori infection, obesity, and potential genetic susceptibility. The positive association between drinking and increased risk of stomach cancer is consistent in stratified analyses. The dose-response analysis showed a clear trend that a higher daily intake of alcohol is associated with a higher risk of stomach cancer.

Dietary Risk Factors Associated with Development of Gastric Cancer in Nepal: A Hospital-Based Case-Control Study

Objectives

Gastric cancer (GC) is one of the most prevalent neoplasms and a leading cause of mortality globally. To our knowledge, its relationship with dietary factors is not adequately studied and understood in the Nepalese context. This study is aimed at exploring the relationship between the possible dietary risk factors responsible for gastric cancer in Nepal.

Methods

A hospital-based matched case-control study was conducted in two specialized cancer hospitals in Nepal. A total of 237 participants (79 cases and 158 controls) were included in the study. Patients diagnosed within one year (incidence case) with histologically confirmed gastric cancer were taken as cases, and healthy visitors of gastric and nongastric cancer patients without past and present history or not a suspected information of gastric cancer were included as controls. A face-to-face interview was conducted using a semi-structured food frequency questionnaire. Backward stepwise conditional logistic regression was used to estimate the magnitude of the association between the independent variables and gastric cancer. Results were presented as the crude odds ratio (COR) and adjusted odds ratio (AOR) with 95% confidence intervals (CI). A P value < 0.05 was considered statistically significant.

Results

In the adjusted multivariable conditional logistic regression model, an increased risk of gastric cancer was more likely to have higher odds among those respondents who had a high consumption of processed meat (AOR = 3.99, 95% CI: 0.90-17.66), preferences of a high amount of fats/oil (AOR = 4.64, 95% CI: 1.56-13.72), and preferences of high amounts of salts (AOR = 4.18, 95% CI: 1.30-13.44). Conversely, those respondents who consumed higher amounts of fruits (AOR = 0.21, 95% CI: 0.07-0.65) were seen to have lower odds of gastric cancer.

Conclusions

Our study found an increased risk of gastric cancer with frequent consumption of red meat, processed meat, high preferences of salt, fats/oil, and condiments. Regular consumption of fruits had a protective effect against gastric cancer. Providing nutrition education, public awareness, and lifestyle modification are primary steps to promote the avoidance of risk factors and change unhealthy dietary habits to prevent gastric cancer in Nepal.

Extraction of Capsinoid and its Analogs From Pepper Waste of Different Genotypes

Pepper, a member of the Capsicum genus of the Solanaceae family, is an annual, cultivated plant that grows in temperate climates. The main analogs of capsinoids, which are the secondary metabolites of peppers, are capsaicin and dihydrocapsaicin. During process, calyxes and peduncles are considered to be waste. Levels of capsinoids in these tissues in not well known. An optimized method was used to extract bioactive materials from the waste products from C. annum L. genotypes. Calyxes and peduncles were collected and dried in the shade. Extractions were in MeOH solutions and the extracts were analyzed using high-performance liquid chromatography (HPLC) to quantify the total amount of capsinoid, capsaicin, and dihydrocapsaicin contents. Capsinoid, and its analogs, were identified in all genotypes at varying concentrations, and their capsaicin and dihydrocapsaicin contents evidenced with liquid chromatography-mass spectrometry (LC-MS). In conclusion, the highest amount of capsinoids was found in chili Samandağ peppers, whereas the lowest amount of capsinoids was found in the red sweet pepper sample. All pepper genotypes, the capsaicin amount was higher comparison to dihydrocapsaicin. Capsanoids and anologues obtained from waste pepper can be used as raw materials in production of value added products.

Effects of lifestyle-related factors on ischemic heart disease according to body mass index and fasting blood glucose levels in Korean adults

OBJECTIVE

To investigate the effects of lifestyle-related factors on ischemic heart disease (IHD) according to body mass index (BMI) and fasting blood glucose (FBG) levels among Korean adults.

METHODS

A total of 119,929 men and 89,669 women (from National Sample Cohort version 2.0, National Health Insurance Service) aged ≥20 years who were examined during 2003-2006 and had no preexisting type 2 diabetes or circulatory diseases were followed until December 2015 to confirm IHD incident cases. Data on lifestyle-related factors (BMI, FBG, diet, smoking, alcohol consumption, and physical activity) were collected at baseline. Lifestyle-related risk factors were defined as mainly vegetable/mainly meat diet, former/current smoking, alcohol consumption ≥3 times/week, and no physical activity. Associations between these factors and IHD were examined using Cox proportional hazards regression models.

RESULTS

High BMI (≥25 kg/m2), high FBG (≥100 mg/dL), mainly meat diet, and former/current smoking were associated with increased risk for IHD. Alcohol consumption ≤twice/week and physical activity ≤twice/week were associated with lower risk of IHD. With increased lifestyle-related risk factors, the risk of IHD also increased in women (hazard ratio [HR] = 3.21, 95% confidence interval [CI] 2.18-4.73) and men (HR = 1.66, 95% CI 1.48-1.85). This increase was larger in women, with a significant sex interaction (p = 0.0001). Significant interactions between BMI and alcohol consumption (p = 0.0002) and between BMI and physical activity (p = 0.0063) were observed. Interactions were seen between FBG level and meal type in both BMI<25 kg/m2 (p = 0.0106) and BMI≥25 kg/m2 (p = 0.0281) and between FBG level and alcohol consumption in BMI ≥25 kg/m2 (p = 0.0118).

CONCLUSIONS

The impact of lifestyle-related factors on IHD was more pronounced in women than in men and may be modified by BMI and FBG level among Korean adults. This might be taken into account when planning individual interventions to reduce IHD risk.

The Association between Salt and Potential Mediators of the Gastric Precancerous Process

Background: The process by which salt affects the gastric precancerous process has not been adequately studied in humans. Methods: We investigated the effects of salt on gastric inflammation, epithelial damage, the density of Helicobacter pylori infection, and gastric epithelial cell proliferation, all of which may be mediators between salt and gastric precancerous/cancerous lesions. These potential mediators were measured using gastric biopsies as: (a) the density of polymorphonuclear and mononuclear cells (gastric inflammation), (b) mucus depletion (gastric epithelial damage), and (c) the severity of H. pylori infection. Salt intake was measured with spot urine samples (using urinary sodium/creatinine ratios), self-reported frequency of adding salt to food, and as total added salt. Results: The average sodium/creatinine ratio (at baseline and post-treatment at five months) was associated with increased epithelial damage over the 12-year follow-up period among those with a greater severity of chronic inflammation and among those with continued H. pylori infection after treatment at five months. This association was stronger when both severe gastric inflammation and H. pylori infection were present at five months (ß: 1.112, 95% CI: 0.377, 1.848). Conclusion: In humans, salt was associated with an increase in epithelial damage in stomachs with more severe previous H. pylori-induced chronic inflammation.

Association between Dietary Salt Intake and Progression in the Gastric Precancerous Process

Gastric cancer is the third leading cause of cancer mortality worldwide. Studies investigating the effect of salt on gastric cancer have mainly used self-reported measures, which are not as accurate as sodium/creatinine ratios because individuals may not know the amount of salt in their food. Using data from a prospective cohort study, we investigated the effect of salt intake on progression to gastric precancerous lesions. Salt intake was estimated by urinary sodium/creatinine ratios, self-reported frequencies of adding salt to food, and total added table salt. We repeated the analyses among groups with and without Helicobacter pylori infection. We did not observe a positive association between salt intake, measured by urinary sodium/creatinine ratio, and overall progression in the gastric precancerous process (adjusted risk ratio (RR): 0.94; 95% confidence interval (CI) 0.76-1.15). We did observe an association between salt intake and increased risk for progression to dysplasia or gastric cancer overall (adjusted risk ratio (RR): 1.32; 95% confidence interval (CI): 0.96-1.81), especially among those who continued to have H. pylori infection at the five-month follow-up (adjusted RR: 1.53; 95% CI: 1.12-2.09), and among those who had persistent H. pylori infection over 12 years (adjusted RR: 1.49; 95% CI: 1.09-2.05). Salt intake may increase the risk of gastric dysplasia or gastric cancer in individuals with H. pylori infection.

Formation and biological targets of botanical o-quinones

The formation of o-quinones from direct 2-electron oxidation of catechols and/or two successive one electron oxidations could explain the cytotoxic/genotoxic and/or chemopreventive effects of several phenolic botanical extracts. For example, poison ivy contains urushiol, an oily mixture, which is oxidized to various o-quinones likely resulting in skin toxicity through oxidative stress and alkylation mechanisms resulting in immune responses. Green tea contains catechins which are directly oxidized to o-quinones by various oxidative enzymes. Alternatively, phenolic botanicals could be o-hydroxylated by P450 to form catechols in vivo which are oxidized to o-quinones. Examples include, resveratrol which is oxidized to piceatannol and further oxidized to the o-quinone. Finally, botanical o-quinones can be formed by O-dealkylation of O-alkoxy groups or methylenedioxy rings resulting in catechols which are further oxidized to o-quinones. Examples include safrole, eugenol, podophyllotoxin and etoposide, as well as methysticin. Once formed these o-quinones have a variety of biological targets in vivo resulting in various biological effects ranging from chemoprevention - > no effect - > toxicity. This U-shaped biological effect curve has been described for a number of reactive intermediates including o-quinones. The current review summarizes the latest data on the formation and biological targets of botanical o-quinones.

High Spicy Food Intake and Risk of Cancer: A Meta-analysis of Case-control Studies

Background:

Studies on the association between spicy food intake and cancer risk have reported inconsistent results. We quantitatively assessed this association by conducting a meta-analysis based on evidence from case–control studies.

Methods:

PubMed, EMBASE, and the Cochrane Library were searched for eligible publications. Combined odds ratios (ORs) with their 95% confidence interval (CI) were calculated using a random- or fixed-effects model. The methodological quality of the included articles was assessed using the Newcastle–Ottawa scale (NOS). All data were analyzed using STATA 11.0 software (version 11.0; StataCorp., College Station, TX, USA). Subgroup analyses were also performed with stratification by region, sex, number of cases, cancer subtype, source of the control group, and NOS score.

Results:

A total 39 studies from 28 articles fulfilled the inclusion criteria for the meta-analysis (7884 patients with cancer and 10,142 controls). Comparison of the highest versus lowest exposure category in each study revealed a significant OR of 1.76 (95% CI = 1.35–2.29) in spite of significant heterogeneity (P < 0.001). In the subgroup analyses, this positive correlation was still found for gastric cancer, different regions, different numbers of cases, different sources of the control group, and high-quality articles (NOS score of ≥ 7). However, no statistically significant association was observed for women, esophageal cancer, gallbladder cancer, or low-quality articles (NOS score of <7). No evidence of publication bias was found.

Conclusions:

Evidence from case–control studies suggested that a higher level of spicy food intake may be associated with an increased incidence of cancer despite significant heterogeneity. More studies are warranted to clarify our understanding of the association between high spicy food intake and the risk of cancer.

Development of quantitative index evaluating anticancer or carcinogenic potential of diet: the anti-cancer food scoring system 1.0

BACKGROUND/OBJECTIVE

Cancer is closely related to diet. One of the most reliable reports of the subject is the expert report from the World Cancer Research Fund & American Institute of Cancer Research (WCRF&AICR). However, majority of the studies including above were written with academic terms and in English. The aim of this study is to create a model, named Anti-Cancer Food Scoring System (ACFS), to provide a simple index of the anticancer potential of food.

SUBJECTS/METHODS

We created ACFS codes of various food groups. The evidence of the ACFS codes was provided by the literature at a level comparable to that suggested in the WCRF&AICR report or from the WCRF&AICR report. The ACFS grade was calculated considering food group, cooking, and normalization. Application was performed for Koreans' 20 common meals, which encompass multinational recipes.

RESULT

We calculated the ACFS grades of Koreans' 20 common meals. The results were not significantly different from the WCRF&AICR guidelines or information from the National Cancer Information Center of Korea. The grades were briefly interpreted as follows: grade S. ideal for cancer prevention; grade A. good for cancer prevention; grade B, might have anticancer potential; grade C, difficult to be regarded as preventive or carcinogenic; grade D, might against cancer prevention; grade E, probably against cancer prevention.

CONCLUSIONS

The ACFS provides a simple index of anticancer potential of diets. This indicator can be useful for the people without expertise, and is effective in evaluating the diets including Asian foods. The ACFS can help design of future clinical or nutritional studies of cancer prevention.

Can Diet Modulate Helicobacter pylori-associated Gastric Pathogenesis? An Evidence-Based Analysis

Helicobacter pylori is involved in the pathogenesis of gastritis, peptic ulcer, and gastric cancer. The infection is prevalent in more than half of the world's population. Although the infection may lead to detrimental consequences, still the majority of the infected individuals only develop mild gastritis. Several factors are behind this paradoxical outcome including virulence of the infecting H. pylori strains, genetic background of the host, and factors related to lifestyle such as dietary habits. Among these, lifestyle including dietary factors was not in the limelight, until recently, as one of the important factors that could modulate H. pylori-linked gastric diseases. This review is directed to gather and elucidate the role of dietary components in augmenting or attenuating pathological processes initiated by H. pylori. Available evidence strongly supports the notion that the diet may play a critical role in defining the final outcome of H. pylori infection particularly if certain dietary components are taken on a regular basis for a long time. Despite a recent surge in research related to the role of dietary ingredients, further studies involving large-scale clinical trials are required to gain a better understanding of the precise role played by the dietary ingredients in H. pylori-associated pathogenesis.

Kimchi and Other Widely Consumed Traditional Fermented Foods of Korea: A Review

Different types of fermented foods such as chongkukjang, doenjang, ganjang, gochujang, and kimchi are plentifully available and widely consumed in north eastern Asian countries including Korea. Among them, kimchi is one of the most popular Korean traditional food. It is prepared by fermenting the baechu cabbage together with other vegetables and lactic acid bacteria (LAB) with functional potential. Many types of ingredients are added to kimchi to enhance its taste, flavor, nutritional value, texture etc. A number of bacteria are involved in the fermentation of kimchi, but LAB are the dominant species in the fermentation process. The addition of other sub ingredients and formation of different by-products during fermentation eventually leads to eradication of putrefactive and pathogenic bacteria, and also increase the functionalities, nutritional and nutraceutical potential of kimchi. Kimchi possesses anti-inflammatory, antibacterial, antioxidant, anticancer, antiobesity, probiotic properties, cholesterol reduction, and antiaging properties. In the present review an attempt has been made to review the different types of fermented foods found in the Korean peninsula with detailed scientific research regarding preparation, processing, structure of the microecosystem, and health benefits of kimchi.

Effect of dietary vitamin C on gastric cancer risk in the Korean population

AIM: To investigate the effects of dietary vitamin C and foods containing vitamin C on gastric cancer risk.

METHODS: Our study included 830 control subjects and 415 patients. Data regarding demographics, medical history, and lifestyle, including dietary and nutrient intake, were collected using reliable self-administered questionnaires. Dietary intake information was collected from the participants using a food frequency questionnaire that has been previously reported as reliable and valid. A rapid urease test and a histological evaluation were used to determine the presence of Helicobacter pylori (H. pylori) infection. Twenty-three vitamin C-contributing foods were selected, representing over 80% of the cumulative vitamin C contribution.

RESULTS: In analyses adjusted for first-degree family history of gastric cancer, education level, job, household income, smoking status, and regular exercise, an inverse association between vitamin C intake and gastric cancer risk was observed for the highest (≥ 120.67 mg/d) vs the lowest (< 80.14 mg/d) intake category [OR (95%CI): 0.64 (0.46-0.88)], with a significant trend across the three intake categories (P = 0.007). No protective effect of vitamin C was detected after stratification by gender. No effect of vitamin C intake on the gastric cancer incidence was found in either men or women infected with H. pylori. Vitamin C-contributing foods, including cabbage [0.45 (0.32-0.63), 0.50 (0.34-0.75), 0.45 (0.25-0.81)], strawberries [0.56 (0.40-0.78), 0.49 (0.32-0.74), 0.52 (0.29-0.93)], and bananas [0.40 (0.29-0.57), 0.41 (0.27-0.62), 0.34 (0.19-0.63)], were protective factors against the risk of gastric cancer based on the results of the overall adjusted analyses and the results for men and women, respectively.

CONCLUSION: A protective effect of vitamin C and vitamin C-contributing foods against gastric cancer was observed. Further studies using larger sample sizes are required to replicate our results.

Diet and cancer risk in the Korean population: a meta- analysis

Many studies have found links between diet and cancer. The summary estimates of the association between dietary factors and cancer risk were investigated using previously reported studies of the Korean population. Gastric cancer risk was inversely associated with the high intake of soy foods [OR (95% CI): 0.32 (0.25-0.40) for soybean, 0.56 (0.45-0.71) for soybean curd, and 0.67 (0.46-0.98) for soymilk], allium vegetables [OR (95% CI): 0.37 (0.26-0.53) for green onion, 0.54 (0.40-0.73) for garlic, and 0.54 (0.35-0.85) for onion], fruits [OR (95% CI): 0.61 (0.42-0.88)], and mushrooms [OR (95% CI): 0.43 (0.21-0.88)]. Salt and Kimchi were associated with an increased gastric cancer risk [OR (95% CI): 1.92 (1.52-2.43) and 2.21 (1.29-3.77), respectively]. Colorectal cancer risk was positively associated with meat intake [OR (95% CI): 1.25 (1.15-1.36)]. Total soy products, soybean curd, and soymilk showed an inverse association with breast cancer risk [OR (95% CI): 0.61 (0.38-0.99), 0.47 (0.34-0.66), and 0.75 (0.57-0.98), respectively]. Green/yellow and light colored vegetables were associated with a reduced risk of breast cancer [OR (95% CI): 0.34 (0.23-0.49) and 0.44 (0.21-0.90), respectively]. Mushroom intake was inversely associated in pre-menopausal women only [OR (95% CI): 0.47 (0.26-0.86)]. In conclusion, soy foods, fruits and vegetables might reduce cancer risk in the Korean population. High salt food might be risk factor for gastric cancer, and intake of high amount of meat might cause colorectal cancer.

Individual having a parent with early-onset gastric cancer may need screening at younger age

AIM: To evaluate whether individuals with gastric cancer (GC) are diagnosed earlier if they have first-degree relatives with GC.

METHODS: A total of 4282 patients diagnosed with GC at National Cancer Center Hospital from 2002 to 2012 were enrolled in this retrospective study. We classified the patients according to presence or absence of first-degree family history of GC and compared age at diagnosis and clinicopathologic characteristics. In addition, we further classified patients according to specific family member with GC (father, mother, sibling, or offspring) and compared age at GC diagnosis among these patient groups. Baseline characteristics were obtained from a prospectively collected database. Information about the family member’s age at GC diagnosis was obtained by questionnaire.

RESULTS: A total of 924 patients (21.6%) had a first-degree family history of GC. The mean age at GC diagnosis in patients having paternal history of GC was 54.4 ± 10.4 years and was significantly younger than in those without a first-degree family history (58.1 ± 12.0 years, P < 0.001). However, this finding was not observed in patients who had an affected mother (57.2 ± 10.0 years) or sibling (62.2 ± 9.8 years). Among patients with family member having early-onset GC (< 50 years old), mean age at diagnosis was 47.7 ± 10.3 years for those with an affected father, 48.6 ± 10.4 years for those with an affected mother, and 57.4 ± 11.5 years for those with an affected sibling. Thus, patients with a parent diagnosed before 50 years of age developed GC 10.4 or 9.5 years earlier than individuals without a family history of GC (both P < 0.001).

CONCLUSION: Early-onset GC before age of 50 was associated with parental history of early-onset of GC. Individual having such family history need to start screening earlier.

Salt processed food and gastric cancer in a Chinese population

To investigate the association between salt processed food and gastric cancer, a hospital based case-control study was conducted in a high risk area of China. One hundred and seven newly diagnosed cases with histological confirmation of gastric cancer and 209 controls were recruited. Information on dietary intake was collected with a validated food frequency questionnaire. Unconditional logistic regression was applied to estimate the odds ratios with adjustment for other potential confounders. Comparing the high intake group with never consumption of salt processed foods, salted meat, pickled vegetables and preserved vegetables were significantly associated with increased risk of gastric cancer. Meanwhile, salt taste preference in diet showed a dose-response relationship with gastric cancer. Our results suggest that consumption of salted meat, pickled and preserved vegetables, are positively associated with gastric cancer. Reduction of salt and salt processed food in diets might be one practical measure to preventing gastric cancer.

The impact of capsaicin intake on risk of developing gastric cancers: a meta-analysis

BACKGROUND

Reported associations of capsaicin with gastric cancer development have been conflicting. Here, we examine 10 published articles that explore these associations using 2,452 cases and 3,996 controls.

METHODS

We used multiple search strategies in MEDLINE through PubMed to seek for suitable articles that had case-control design with gastric cancer as outcome.

RESULTS

The outcomes of our study shows protection (odds ratio [OR] 0.55, P = 0.003) and susceptibility (OR 1.94, P = 0.0004), both significant with low and medium-high intake of capsaicin, respectively, although under relatively heterogeneous conditions (P(heterogeneity) = <0.0001). Outlier analysis resulted in loss of overall heterogeneity (P = 0.14) without affecting the pooled ORs. Among the subgroups, low intake elicited protection in both Korean (OR 0.37) and Mexican (OR 0.63) populations while high intake rendered these subgroups susceptible (OR 2.96 and OR 1.57, respectively). These subgroup values were highly significant (P = 0.0001-0.01) obtained in heterogeneous conditions (P(heterogeneity) < 0.0001-0.04). The homogeneous (P(heterogeneity) = 0.27-0.37) H. pylori (OR 0.60 and 1.69) effects were highly significant (P < 0.001) in the low and medium-high intake analyses, respectively. Given outcomes from the tests of interaction, high capsaicin intake is significantly different from the protection that low consumption offers.

CONCLUSIONS

This meta-analysis implies moderation in capsaicin consumption in order to derive its protective benefits.

Effects of intensive nutrition education on nutritional status and quality of life among postgastrectomy patients

Purpose

We examined the effects of 3 months of intensive education (IE) after hospital discharge compared to conventional education (CE) on nutritional status and quality of diet and life among South Korean gastrectomy patients.

Methods

The study was conducted among 53 hospitalized gastrectomy in-patients (IE group, n = 28; CE group, n = 25) at Kyung Hee University Hospital at Gangdong. Baseline data were collected from electronic medical records and additional information was gathered via anthropometric measurements, assessment of nutritional status through a patient-generated, subjective global assessment (PG-SGA), diet assessment, and measures of self-efficacy and satisfaction with meals for 3 months following hospital discharge.

Results

Total PG-SGA scores were significantly higher in the CE group than in the IE group at 3-week post-discharge (5.2 in the IE group vs. 10.4 in the CE group, P < 0.001), with higher scores indicating a greater severity of malnutrition. Energy intake over the 3 months increased in both the IE group (from 1,390 to 1,726 kcal/day) and the CE group (from 1,227 to 1,540 kcal/day). At 3-week post-discharge, the IE group had significantly higher daily protein and fat intake (P < 0.05). Self-efficacy improved in each category (P < 0.001), except for 'difficulty eating adequate food'. When assessing satisfaction with meals, there was a difference in the 'satisfaction with the current meal size' (P < 0.001) and 'satisfaction with the menu content' (P < 0.001).

Conclusion

Nutritional status among gastrectomy patients in the IE group improved. Relative to the CE control, the IE group demonstrated improved self-efficacy and meal satisfaction 3-week post-discharge.

Soy and isoflavone consumption and risk of gastrointestinal cancer: a systematic review and meta-analysis

PURPOSE

Evidence suggests that soy foods have chemoprotective properties that may reduce the risk of certain cancers such as breast and prostate cancer. However, data involving gastrointestinal (GI) have been limited, and the evidence remains controversial. This study aims to determine the potential relationship between dietary soy intake and GI cancer risk with an evaluation of the effects of isoflavone as an active soy constituent.

METHODS

Relevant studies were identified after literature search via electronic databases through May 2014. Subgroup analysis for isoflavone intake (studies n = 10) was performed. Covariants including gender types, anatomical subsites and preparation methods were also evaluated. Pooled adjusted odds ratios (ORs) comparing highest and lowest categories of dietary pattern scores were calculated using a random effects model.

RESULTS

Twenty-two case-control and 18 cohort studies were included for meta-analysis, which contained a total of 633,476 participants and 13,639 GI cancer cases. The combined OR was calculated as 0.93 (95% CI 0.87-0.99; p value heterogeneity = 0.01), showing only a slight decrease in risk, the association was stronger for colon cancer (OR 0.92; 95% CI 0.96-0.99; p value heterogeneity = 0.163) and colorectal cancer (CRC) (OR 0.92; 95% CI 0.87-0.97; p value heterogeneity = 0.3). Subgroup analysis for isoflavone intake showed a statistically significant risk reduction with a risk estimate of 0.73 (95% CI 0.59-0.92; p value heterogeneity = 0), and particularly for CRC (OR 0.76; 95% CI 0.59-0.98; p value heterogeneity = 0).

CONCLUSION

This study provides evidence that soy intake as a food group is only associated with a small reduction in GI cancer risk. Separate analysis for dietary isoflavone intakes suggests a stronger inverse association.

Attributable fraction of tobacco smoking on cancer using population-based nationwide cancer incidence and mortality data in Korea

Background

Smoking is by far the most important cause of cancer that can be modified at the individual level. Cancer incidence and mortality rates in Korea are the highest among all Asian countries, and smoking prevalence in Korean men is one of the highest in developed countries. The purpose of the current study was to perform a systematic review and provide an evidence-based assessment of the burden of tobacco smoking-related cancers in the Korean population.

Methods

Sex- and cancer-specific population-attributable fractions (PAF) were estimated using the prevalence of ever-smoking and second-hand smoking in 1989 among Korean adults, respectively, and the relative risks were estimated from the meta-analysis of studies performed in the Korean population for ever-smoking and in the Asian population for passive smoking. National cancer incidence data from the Korea Central Cancer Registry and national cancer mortality data from Statistics Korea for the year 2009 were used to estimate the cancer cases and deaths attributable to tobacco smoking.

Results

Tobacco smoking was responsible for 20,239 (20.9%) cancer incident cases and 14,377 (32.9%) cancer deaths among adult men and 1,930 (2.1%) cancer incident cases and 1,351 (5.2%) cancer deaths among adult women in 2009 in Korea. In men, 71% of lung cancer deaths, 55%–72% of upper aerodigestive tract (oral cavity, pharynx, esophagus and larynx) cancer deaths, 23% of liver, 32% of stomach, 27% of pancreas, 7% of kidney and 45% of bladder cancer deaths were attributable to tobacco smoking. In women the proportion of ever-smoking-attributable lung cancer was 8.1%, while that attributable to second-hand smoking among non-smoking women was 20.5%.

Conclusions

Approximately one in three cancer deaths would be potentially preventable through appropriate control of tobacco smoking in Korean men at the population level and individual level. For Korean women, more lung cancer cases and deaths were attributable to second-hand than ever-smoking. Effective control programs against tobacco smoking should be further developed and implemented in Korea to reduce the smoking-related cancer burden.

Red meat consumption is associated with an increased overall cancer risk: a prospective cohort study in Korea

Cancer is a leading cause of death, and the dietary pattern in Korea is changing rapidly from a traditional Korean diet to a Westernised diet. In the present study, we investigated the effects of dietary factors on cancer risk with a prospective cohort study. Among 26 815 individuals who participated in cancer screening examinations from September 2004 to December 2008, 8024 subjects who completed a self-administered questionnaire concerning demographic and lifestyle factors, and a 3 d food record were selected. As of September 2013, 387 cancer cases were identified from the National Cancer Registry System, and the remaining individuals were included in the control group. The hazard ratio (HR) of cancer for the subjects older than or equal to 50 years of age was higher (HR 1·80, 95 % CI 1·41, 2·31; P< 0·0001) than that for the other subjects. Red meat consumption, Na intake and obesity (BMI ≥ 25 kg/m2) were positively associated with overall cancer incidence in men (HR 1·41, 95 % CI 1·02, 1·94; P= 0·0382), gastric cancer (HR 2·34, 95 % CI 1·06, 5·19; P= 0·0365) and thyroid cancer (HR 1·56, 95 % CI 1·05, 2·31; P= 0·0270), respectively. Participants who had at least three dietary risk factors among the high intakes of red meat and Na, low intakes of vegetables and fruits, and obesity suggested by the World Cancer Research Fund/American Institute for Cancer Research at baseline tended to have a higher risk of cancer than the others (HR 1·26, 95 % CI 0·99, 1·60; P= 0·0653). In summary, high intakes of red meat and Na were significant risk factors of cancer among Koreans.

Dietary salt intake and risk of gastric cancer

Humans began to use large amounts of salt for the main purpose of food preservation approximately 5,000 years ago and, although since then advanced technologies have been developed allowing drastic reduction in the use of salt for food storage, excess dietary salt intake remains very common. Gastric cancer is a common neoplasia, and dietary factors, including salt consumption, are considered relevant to its causation. A number of experimental studies supported the cocarcinogenic effect of salt through synergic action with Helicobacter pylori infection, in addition to some independent effects such as increase in the rate of cell proliferation and of endogenous mutations. Many epidemiological studies analyzed the relationship between excess salt intake and risk of gastric cancer. Both cross-sectional and prospective studies indicated a possibly dose-dependent positive association. In particular, a comprehensive meta-analysis of longitudinal studies detected a strong adverse effect of total salt intake and salt-rich foods on the risk of gastric cancer in the general population. Altogether, the epidemiological, clinical, and experimental evidence supports the possibility of a substantial reduction in the rates of gastric cancer through progressive reduction in population salt intake.

Polymorphisms of the TLR4 gene and risk of gastric cancer

OBJECTIVE

Toll-like receptor 4 (TLR4) is an important lipo-polysaccharide (LPS) receptor in gastric epithelial cell signaling transduction and plays critical roles in the development and progression of gastric cancer (GC). We investigated the effects of TLR4 gene polymorphisms and gene-environmental interactions on the risk of GC in Northeastern China.

METHODS

We genotyped two single-nucleotide polymorphisms (SNPs) in TLR4 (rs10116253 and rs1927911) in 217 GC patients and 294 cancer-free controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Odds ratio (OR) and 95% confidence intervals (CIs) were estimated by unconditional logistic-regression models.

RESULTS

Individuals carrying CC genotype of rs10116253 and TT genotype of rs1927911 had a significantly decreased risk of GC (adjusted OR=0.33, 95% CI 0.18-0.60, P<0.001 and adjusted OR=0.37, 95% CI 0.21-0.67, P=0.001 respectively), compared with TT genotype of rs10116253 and CC genotype of rs1927911. In addition, the SNP effects were additive to the effects of some known environmental factors without any interaction between them in the susceptibility to GC.

CONCLUSION

Our data suggested that TLR4 gene polymorphisms may be associated with a decreased risk of GC in Chinese population. And these SNPs and their combined effects with environmental factors may be associated with the risk of GC.

Intake of specific nonfermented soy foods may be inversely associated with risk of distal gastric cancer in a Chinese population

Because the association between soy consumption and gastric cancer is inconsistent, we evaluated the putative preventive effect of soy food on gastric cancer risk in the Shanghai Women's and Men's Health Studies, comprising a total of 128,687 participants. Intake of nonfermented soy foods was estimated using 2 validated food-frequency questionnaires. HRs were calculated with 95% CIs for intake amounts of total nonfermented soy food intake, soy protein, and isoflavones as well as individual soy food groups using Cox proportional hazards regression. A total of 493 distal gastric cancer cases were identified by 2010. Although all risk estimates for summary measures of soy food intake above the lowest quartile (quartile 1) were suggestive of a protective effect, no statistically significant associations with risk of distal gastric cancer were found. Among the separate soy food groups, significant reductions in risk of distal gastric cancer by increasing intake of tofu were found in men in quartile 2 (HR: 0.59; 95% CI: 0.40, 0.86), quartile 3 (HR: 0.62; 95% CI: 0.44, 0.88), and quartile 4 (HR: 0.64; 95% CI: 0.42, 0.99), resulting in a significant trend (P-trend = 0.02). Dry bean intake was also inversely associated with decreased risk of gastric cancer, but in postmenopausal women only [quartile 2 (HR: 0.54; 95% CI: 0.30, 0.96); quartile 3 (HR: 0.90; 95% CI: 0.64, 1.27); and quartile 4 (HR: 0.63; 95% CI: 0.43, 0.91)], resulting in a significant trend (P-trend = 0.03). Overall, our study found no statistically significant association between nonfermented soy food intake and distal gastric cancer risk, though the data supported the hypothesis that tofu may protect against distal gastric cancer in men and dry bean consumption may decrease the risk of gastric cancer in postmenopausal women.

Dietary aflatoxin B1 intake, genetic polymorphisms of CYP1A2, CYP2E1, EPHX1, GSTM1, and GSTT1, and gastric cancer risk in Korean

PURPOSE

We investigated the effects of aflatoxin B1 (AFB1) intake, genetic polymorphisms of AFB1 metabolic enzymes, and interactions between the polymorphisms and intake of AFB1 with regard to the risk of gastric cancer in Korean.

METHODS

The participants in the study included 477 gastric cancer patients and 477 age- and sex-matched control subjects. Direct interviews and a structured questionnaire were used to determine the level of exposure to AFB1, and the GoldenGate assay and multiplex polymerase chain reaction were used for genotypic analyses of the cytochrome P450 1A2 (CYP1A2), cytochrome P450 1E1, epoxide hydrolase 1, and glutathione S-transferase genes.

RESULTS

The probable daily intake of AFB1 was significantly higher among gastric cancer patients than among control subjects (cases vs. controls: 1.91 ± 0.87 vs. 1.65 ± 0.72 ng/kg bw/day, p < 0.0001), and increased AFB1 intake was significantly associated with an elevated risk of gastric cancer (odds ratio 1.94; 95 % confidence interval 1.43-2.63). However, genetic polymorphisms of AFB1 metabolic enzymes were not associated with gastric cancer, with the exception of CYP1A2. Moreover, there was no interaction between AFB1 intake and the genotypes of metabolic enzymes that affect gastric cancer risk.

CONCLUSIONS

Our results suggest that dietary AFB1 exposure might be associated with a risk of gastric cancer. However, the effect of AFB1 on gastric carcinogenesis may not be modulated by genetic polymorphisms of AFB1 metabolic enzymes.

Cruciferous vegetable consumption and gastric cancer risk: a meta-analysis of epidemiological studies

The relationship between consumption of cruciferous vegetables (CV) and risk of gastric cancer has been investigated by many studies, but remains controversial. We carried out a meta-analysis to summarize available evidence from epidemiological studies on this point. Relevant published reports of CV intake and gastric cancer were identified using MEDLINE (PubMed), EMBASE, and Web of Science databases through to the end of September 2012. We pooled the relative risk from individual studies using a fixed- or random-effects model and carried out heterogeneity and publication bias analyses. Sixteen case-control and six prospective studies were included in our analysis. When all studies were pooled, we yielded a significantly inverse association between CV (relative risk = 0.81; 95% confidence interval, 0.75-0.88) intake and gastric cancer risk, with little heterogeneity (Q = 27.27, P = 0.292, I(2) = 12.0%). Specific analysis for cabbage intake yielded similar result. When separately analyzed, case-control studies of CV intake yielded significant results and the results of prospective studies showed borderline statistical significance. Moreover, significant results were consistent for high-quality studies, for North American, European, and Asian studies, for studies on males, and for studies on non-cardia gastric cancer. Findings from this meta-analysis provide evidence that high intake of CV was inversely associated with the risk of gastric cancer and non-cardia gastric cancer in humans. Further studies on other specific CV, food preparation methods, and stratified results by anatomic cancer site and histological type should be extended in the future.

Therapeutic effects of fermented soycrud on phenotypes of atopic dermatitis induced by phthalic anhydride

Atopic dermatitis (AD), which is known as the most common pruritic skin disease, is caused by epidermal barrier dysfunction, allergies, microwave radiation, histamine intolerance, and genetic defects. To investigate the therapeutic effects of fermented soycrud (FSC) on AD pathology, alteration of AD phenotypes induced by phthalic anhydride (PA) treatment was assessed by ear thickness analysis, measurement of immune-related organ weights, ELISA, and histological and pathological analyses of ICR mice after FSC treatment for 2 weeks. Except for water content, the concentrations of most major components were lower in FSC compared to common tofu (CMT). Thymus and lymph node weights were significantly reduced in ICR mice treated with PA+CMT or PA+FSC, whereas spleen and body weights were maintained. Elevation of ear thickness induced by PA treatment was rapidly diminished in the CMT- and FSC-treated groups, although there was no significant difference between the two groups. Furthermore, significant reduction of epidermal thickness was detected in both the PA+CMT- and PA+FSC-treated groups. However, IgE concentration and dermal thickness were reduced only by PA+FSC treatment, whereas PA+CMT treatment maintained levels comparable to PA+vehicle treatment. The number of infiltrated mast cells was higher in the PA+vehicle-treated group compared to the untreated control. Following CMT or FSC treatment, mast cell infiltration was slightly reduced, although the CMT-treated group showed greater cell numbers. These results indicate that FSC may significantly relieve the phenotypes of AD induced by PA treatment and should be considered as a potential candidate for AD therapy.

Pre-existing diabetes mellitus increases the risk of gastric cancer: A meta-analysis

AIM: To systematically assess the association between diabetes and incidence of gastric cancer.

METHODS: We searched MedLine (PubMed), EMBASE, and the Cochrane Library without any limitations with respect to publication date or language, we also searched the references of qualifying articles. Case-control studies and cohort studies comparing the risk of gastric cancer between diabetic patients and control subjects were included. We excluded studies reporting only standardized incidence ratios without control groups and those that investigated only mortality but not incidence. Seventeen studies met our criteria, and the qualities of these studies were assessed using the Newcastle-Ottawa Quality Assessment Scale. We performed a meta-analysis of pre-existing diabetes and gastric cancer incidence using the DerSimonian-Laird method for random-effects. For subgroup analyses, we separated the studies by study type, region, sex and method to determine confounding factors and reliability. We also conducted subgroup analyses to examine the effects of smoking, Helicobacter pylori (H. pylori) infection, and cancer site. Publication bias was evaluated using Begg’s test.

RESULTS: A random-effects model meta-analysis showed an increased gastric cancer risk in diabetic patients [relative risk (RR) = 1.19; 95%CI: 1.08-1.31]. Subgroup analyses indicated that this result persisted in cohort studies (RR = 1.20; 95%CI: 1.08-1.34), in studies on populations of both Western (RR = 1.18; 95%CI: 1.03-1.36) and Eastern countries (RR = 1.19; 95%CI: 1.02-1.38), in a female subgroup (RR=1.24; 95%CI: 1.01-1.52), and in highly qualified studies (RR = 1.17; 95%CI: 1.05-1.31). Moreover, these results persisted when the analysis was confined to studies adjusted for well-known gastric cancer risk factors such as smoking (RR = 1.17; 95%CI: 1.01-1.34) and H. pylori infection (RR = 2.35; 95%CI: 1.24-4.46).

CONCLUSION: Pre-existing diabetes mellitus may increase the risk of gastric cancer by approximately 19%. This effect seems to be unrelated to geographical region.

Sodium and potassium intake patterns and trends in South Korea

We examined major trends and patterns regarding sodium and potassium intake and the ratio of sodium and potassium in the diets of South Koreans. We used data from 24-h dietary recall data from 10,267, 8819 and 9264 subjects ages > or =2 years in the 1998, 2005 and 2009 Korean National Health and Nutrition Examination Surveys, respectively. Mean sodium intake did not change significantly between 1998 and 2009 (4.6 vs. 4.7 g per day), while potassium intake increased significantly (2.6 vs. 2.9 g per day (P<0.001)). The major dietary sodium sources were kimchi, salt, soy sauce and soybean paste, and most potassium came from unprocessed foods (white rice, vegetables, kimchi and fruits). About 50% of the participants consumed > or =4 g of sodium per capita per day. The proportion of respondents consuming four to six grams of potassium per capita per day increased from 10.3% in 1998 to 14.3% in 2009 (P<0.001), and the sodium-potassium ratio decreased from 1.88 to 1.71 (P<0.001). One major implication is that efforts to reduce sodium in processed foods will be ineffective and future efforts must focus on both education to reduce use of sodium in food preparation and sodium replacement in salt, possibly with potassium.

A Comprehensive Review of the Carcinogenic and Anticarcinogenic Potential of Capsaicin

Human exposure to capsaicin, the most abundant pungent chili pepper component, is ubiquitous. Evaluation of capsaicin’s carcinogenic potential has produced variable results in in vitro and in vivo genotoxicity and carcinogenicity assays. The capsaicin tested in older studies was often from pepper plant extracts and included other capsaicinoids and diverse impurities. Recent studies utilizing high-purity capsaicin and standardized protocols provide evidence that the genotoxic and carcinogenic potential of capsaicin is quite low and that the purity of capsaicin is important. Several small epidemiological studies suggest a link between capsaicin consumption and stomach or gall bladder cancer, but contamination of capsaicin-containing foods with known carcinogens renders their interpretation problematic. The postulated ability of capsaicin metabolites to damage DNA and promote carcinogenesis remains unsupported. Anticancer activities of capsaicin have been widely reported, as it inhibits the activity of carcinogens and induces apoptosis in numerous cancer cell lines in vitro and explanted into rodents. Diverse mechanisms have been postulated for capsaicin’s anticancer properties. One hypothesis is that inhibition of cytochrome P450 enzymes—particularly CYP2E1—retards carcinogen activation but is contradicted by the low potency of capsaicin for CYP inhibition. The potential for dietary capsaicin to act as a chemopreventative is now widely postulated.

Pickled food and risk of gastric cancer--a systematic review and meta-analysis of English and Chinese literature

BACKGROUND

Ecological and experimental studies have suggested an increased risk of gastric cancer in relation to consumption of pickled vegetables in East Asia.

METHODS

We conducted a meta-analysis of epidemiologic observational studies to evaluate the existing evidence. Searching PubMed, Vip Chinese Periodical, and China National Knowledge Infrastructure databases, we found a total of 60 studies, 50 case-control, and 10 prospective. We compared gastric cancer risk in pickled vegetable/food users versus nonusers (11 studies) or versus those in the lowest reported category of use (49 studies). Pooled results were computed with random-effects models.

RESULTS

Among case-control studies, 30 showed significant increased risk and one showed significant decreased risk. Among prospective studies, two showed a significant increased risk but none showed a significant decreased risk. The OR (95% CI) was 1.52 (1.37-1.68) for the overall association, 1.56 (1.39-1.75) for case-control, and 1.32 (1.10-1.59) for cohort studies. The OR (95% CI) was 1.89 (1.29-2.77) in Korean, 1.86 (1.61-2.15) in Chinese, and 1.16 (1.04-1.29) in Japanese studies, and 1.14 (0.96-1.35) in studies from other countries. There was high heterogeneity in overall and subgroup analyses. There was little evidence for publication bias.

CONCLUSION

Our results suggest a potential 50% higher risk of gastric cancer associated with intake of pickled vegetables/foods and perhaps stronger associations in Korea and China.

IMPACT

The results of this study may offer ways to reduce the risk of gastric cancer in highly populated areas with high incidence of gastric cancer.

Capsaicin consumption, Helicobacter pylori CagA status and IL1B-31C>T genotypes: a host and environment interaction in gastric cancer

Gastric cancer (GC) has been associated with a complex combination of genetic and environmental factors. In contrast to most countries, available information on GC mortality trends showed a gradual increase in Mexico. Our aim was to explore potential interactions among dietary (chili pepper consumption), infectious (Helicobacter pylori) and genetic factors (IL1B-31 genotypes) on GC risk. The study was performed in three areas of Mexico, with different GC mortality rates. We included 158 GC patients and 317 clinical controls. Consumption of capsaicin (Cap), the pungent active substance of chili peppers, was estimated by food frequency questionnaire. H. pylori CagA status was assessed by ELISA, and IL1B-31 genotypes were determined by TaqMan assays and Pyrosequencing in DNA samples. Multivariate unconditional logistic regression was used to estimate potential interactions. Moderate to high Cap consumption synergistically increased GC risk in genetically susceptible individuals (IL1B-31C allele carriers) infected with the more virulent H. pylori (CagA+) strains. The combined presence of these factors might explain the absence of a decreasing trend for GC in Mexico. However, further research on gene-environment interactions is required to fully understand the factors determining GC patterns in susceptible populations, with the aim of recommending preventive measures for high risk individuals.

Comparison of sensory, physiological, personality, and cultural attributes in regular spicy food users and non-users

Some individuals savor spicy foods, while others avoid them. Reasons underlying this range of hedonic responses are unknown. The purpose of this study was to explore the basis for individual differences in preference for spicy foods. Regular spicy food users (n=13) and non-users (n=12) were characterized for selected sensory, physiological, personality, and cultural attributes. Individual differences between users and non-users were primarily related to sensory and cultural attributes (i.e., a higher proportion of users reported consuming spicy foods since childhood and users rated spicy foods as more palatable and were better able to discriminate this burn than non-users). Users and non-users exhibited comparable responsiveness to noxious pressure pain, oral tactile sensitivity, and auditory sensitivity, varying only in responsiveness to oral thermal heat (i.e., users were more sensitive to increases than non-users). Studied personality traits did not vary between users and non-users. These findings suggest that prior experience, rather than physiological adaptation or personality differences, may best predict preference for spicy foods. These findings are of public health interest, given that spicy food consumption is reported to confer weight management and food safety benefits.

Gastric cancer epidemiology in Korea

Gastric cancer has been the most commonly diagnosed cancer in Korea although the age-standardized mortality and incidence has decreased gradually during last two decades. Helicobacter pylori infection and cigarette smoking are well-established risk factors, and the role of dietary factors, such as salted foods, fresh vegetables and fruits, soy foods, and processed or grilled meats on gastric carcinogenesis has been suggested. In this review, we review national and international gastric cancer statistics, studies on environmental risk factors conducted in the Korean population, and gastric cancer screening activities.

Ecological study for refrigerator use, salt, vegetable, and fruit intakes, and gastric cancer

We used an ecological approach to determine the correlation between vegetable, fruit and salt intakes, refrigerator use, and gastric cancer mortality in Korean population. Information on fruit and vegetable intakes per capita from the National Health and Nutrition Survey, death certificate data from the National Statistical office, refrigerator per household data from Korean Statistical Information Service, and salt/sodium intake data from a cross-sectional survey were utilized. Correlation coefficients were calculated between vegetable and fruit intakes, refrigerator per household, and gastric cancer mortality and between salt and sodium intakes, and gastric cancer mortality and incidence in the four areas. With 5, 10, and 15 years lag time, refrigerator usage and fruit intake were negatively associated with gastric cancer mortality (p < 0.01), but vegetable intake was not associated with gastric cancer mortality. When estimates of salt/sodium intake evaluated by 24-h urine collection in four areas of Korea were compared to the gastric cancer mortality and incidence in these regions, positive correlation was shown between salt/sodium intake, and gastric cancer incidence and mortality. Negative associations between refrigerator use, fruit intake, and gastric cancer mortality and positive associations between salt/sodium intake and gastric cancer mortality and incidence were suggested.

Fermented and non-fermented soy food consumption and gastric cancer in Japanese and Korean populations: a meta-analysis of observational studies

Soy food is known to contribute greatly to a reduction in the risk of gastric cancer (GC). However, both Japanese and Korean populations have high incidence rates of GC despite the consumption of a wide variety of soy foods. One primary reason is that they consume fermented rather than non-fermented soy foods. In order to assess the varying effects of fermented and non-fermented soy intake on GC risk in these populations, we conducted a meta-analysis of published reports. Twenty studies assessing the effect of the consumption of fermented soy food on GC risk were included, and 17 studies assessing the effect of the consumption of non-fermented soy food on GC risk were included. We found that a high intake of fermented soy foods was significantly associated with an increased risk of GC (odds ratio [OR] = 1.22, 95% confidence interval [CI] = 1.02-1.44, I(2) = 71.48), whereas an increased intake of non-fermented soy foods was significantly associated with a decreased risk of GC (overall summary OR = 0.64, 95% CI = 0.54-0.77, I(2) = 64.27). These findings show that a high level of consumption of non-fermented soy foods, rather than fermented soy foods, is important in reducing GC risk.