Inverse association between intake of cereal fiber and risk of gastric cardia cancer

The association between dietary fiber intake and gastric cancer: a pooled analysis of 11 case-control studies

PURPOSE

Gastric cancer (GC) is among the leading causes of cancer mortality worldwide. The objective of this study was to investigate the association between dietary fiber intake and GC.

METHODS

We pooled data from 11 population or hospital-based case-control studies included in the Stomach Cancer Pooling (StoP) Project, for a total of 4865 histologically confirmed cases and 10,626 controls. Intake of dietary fibers and other dietary factors was collected using food frequency questionnaires. We calculated the odds ratios (OR) and 95% confidence intervals (CI) of the association between dietary fiber intake and GC by using a multivariable logistic regression model adjusted for study site, sex, age, caloric intake, smoking, fruit and vegetable intake, and socioeconomic status. We conducted stratified analyses by these factors, as well as GC anatomical site and histological type.

RESULTS

The OR of GC for an increase of one quartile of fiber intake was 0.91 (95% CI: 0.85, 0.97), that for the highest compared to the lowest quartile of dietary fiber intake was 0.72 (95% CI: 0.59, 0.88). Results were similar irrespective of anatomical site and histological type.

CONCLUSION

Our analysis supports the hypothesis that dietary fiber intake may exert a protective effect on GC.

Daily Diet and Nutrition Risk Factors for Gastric Cancer Incidence in a Japanese Population

Background/Aims

: Nutritional factors associated with gastric cancer (GC) are not completely understood. We aimed to determine the effect of nutrient intake on the incidence of GC.

Methods

: This was a post hoc analysis of a prospective trial that evaluated modalities for GC screening in participants aged 30 to 74 years living in high-risk areas for GC in Japan between June 2011 and March 2013. The patients were followed up for GC incidence for 6 years. All participants completed a self-administered food frequency questionnaire (FFQ) upon enrollment before GC screening. Daily nutrient intake was calculated from the FFQ and dichotomized at each cutoff value using receiver operating characteristic analysis. Risk factors associated with GC incidence were investigated in terms of nutrient intake and participant characteristics using Cox proportional hazards regression analysis.

Results

: Overall, 1,147 participants were included in this analysis. The median age was 62 years, and 50.7% of the participants were men. The median follow-up period was 2,184 days. GC was detected in 25 participants during the follow-up. Multivariate Cox proportional hazards regression analysis revealed that the intake of sodium (adjusted hazards ratio [aHR], 3.905; 95% confidence interval [CI], 1.520 to 10.035; p=0.005) and vitamin D (aHR, 2.747; 95% CI, 1.111 to 6.788, p=0.029) were positively associated with GC incidence, whereas the intake of soluble dietary fiber (aHR, 0.104; 95% CI, 0.012 to 0.905; p=0.040) was inversely associated with GC incidence.

Conclusions

: Daily high intake of sodium and vitamin D and low soluble dietary fiber intake are associated with GC incidence.

Prevalence and risk factors of belching disorders: A cross-sectional study among freshman college students

OBJECTIVES

Belching disorders seriously affect quality of life; however, their prevalences and risk factors remain unknown. The aim of our study was to determine the prevalence and risk factors, particularly lifestyle factors, of belching disorders among freshman college students in central China.

METHODS

A cross-sectional study was conducted in September 2019 in Huazhong University of Science and Technology (Wuhan, Hubei Province, China). The subjects were asked to complete a self-administered questionnaire for data collection, including sociodemographic information, lifestyle factors, and gastrointestinal symptoms. Belching disorder was diagnosed based on the Rome IV criteria. Univariate and multivariate logistic regression analyses were performed to determine the risk factors for belching disorders.

RESULTS

A total of 3335 subjects were enrolled, and 78.26% were men. Among them, 1.95% (65/3335) reported belching disorders. Significant differences in the Pittsburgh Sleep Quality Index (PSQI), Student-Life Stress Inventory (SLSI) scores, and consumption of whole grains, black tea, coffee were found between the belching and non-belching groups. Multivariate logistic regression analysis showed that coffee consumption at least once weekly and a high total SLSI score (over mean + standard deviation) were independent risk factors for belching disorders, while intake of whole grains at least once weekly was a protective factor.

CONCLUSIONS

Excessive belching is a common disorder among freshman college students in central China. Lifestyle factors, including consumption of whole grains and coffee, and stress, were associated with belching disorders. Therefore, dietary intervention may be a potential management for belching disorders.

Gluten Intake and Risk of Digestive System Cancers in 3 Large Prospective Cohort Studies

BACKGROUND & AIMS

In patients with celiac disease, gluten triggers an immune reaction that damages small intestinal villi and may increase long-term risk of gastrointestinal cancer. However, the health impacts of gluten in the general population are understudied. We aimed to examine the association between gluten intake and risk of digestive system cancers among individuals without celiac disease.

METHODS

We leveraged longitudinal data from 3 prospective cohorts, the Nurses' Health Study (1984-2018, 73,166 women aged 65.1 ± 10.8 years), Nurses' Health Study II (1991-2017, 90,423 women aged 49.1 ± 8.2 years), and Health Professionals Follow-Up Study (1986-2016, 42,617 men aged 64.8 ± 10.8 years). Using Cox proportional hazards regression, we estimated hazard ratios and 95% confidence intervals of digestive system cancers according to quintiles of gluten intake assessed from food frequency questionnaires.

RESULTS

During 4,801,513 person-years of follow-up, we documented 6231 incident digestive system cancer cases among 3 cohorts. After adjusting for a wide-range of risk factors, including body mass index, physical activity, diet quality, gluten intake was not associated with an increased risk of digestive system cancer, with a hazard ratio of 0.94 (95% confidence interval, 0.87-1.02) comparing the highest with the lowest quintile of gluten intake (P trend = .05). Similar null associations were found for individual digestive system cancers: oral cavity and oropharyngeal cancer, esophageal cancer, stomach cancer, small intestine cancer, colorectal cancer, pancreatic cancer, gallbladder cancer, and liver cancer.

CONCLUSIONS

Gluten intake was not associated with risk of digestive system cancers in adults without celiac disease. Restricting dietary gluten is unlikely to be beneficial to the prevention of digestive system cancers in the general population.

Dietary fiber intake and risk of gastric cancer: The Japan Public Health Center-based prospective study

Evidence of the association between dietary fiber intake and gastric cancer (GC) risk from prospective studies is limited. We examined the association between dietary fiber intake and GC risk in a large prospective study. A total of 91 946 eligible Japanese aged 45 to 74 years (42 773 men and 49 173 women) participated in a population-based cohort study (Japan Public Health Center-based prospective study). From a validated food frequency questionnaire with 138 food items, total and food source-specific dietary fiber intake was calculated as exposure. The hazard ratio (HR) and the 95% confidence interval (CI) of GC incidence according to quintile of dietary fiber intake were examined after adjusting for confounding factors. In total, 2228 GC cases (1559 men and 669 women) were observed during the 15.0 years follow-up. Total dietary fiber intake was not associated with GC risk; however, a marginally increased risk trend because of high HR in the highest quintile of total fiber intake was found in women (HR [95% CI] in Q5 vs Q1: 0.95 [0.79-1.14], P for trend .30 in men, HR [95% CI] 1.25 [0.98-1.61], P for trend .05 in women). Stratification by tumor location did not change the results. A marginal but not significant inverse trend was observed regarding cereal fiber intake and GC risk in men. Total dietary fiber intake was not associated with GC risk. Further studies are warranted to confirm this association.

The Impact of Whole Grain Intake on Gastrointestinal Tumors: A Focus on Colorectal, Gastric, and Esophageal Cancers

Cereals are one of staple foods in human diet, mainly consumed as refined grains. Nonetheless, epidemiological data indicate that whole grain (WG) intake is inversely related to risk of type 2 diabetes, cardiovascular disease, and several cancer types, as well as to all-cause mortality. Particularly responsive to WG positive action is the gastrointestinal tract, daily exposed to bioactive food components. Herein, we shall provide an up-to-date overview on relationship between WG intake and prevention of gastrointestinal tumors, with a particular focus on colorectal, stomach, and esophagus cancers. Unlike refined counterparts, WG consumption is inversely associated with risk of these gastrointestinal cancers, most consistently with the risk of colorectal tumor. Some WG effects may be mediated by beneficial constituents (such as fiber and polyphenols) that are reduced/lost during milling process. Beside health-promoting action, WGs are still under-consumed in most countries; therefore, World Health Organization and other public/private stakeholders should cooperate to implement WG consumption in the whole population, in order to reach nutritionally effective intakes.

Food and Gastroesophageal Reflux Disease

Gastroesophageal reflux disease is a chronic condition with a high prevalence in western countries. Transient lower esophageal sphincter relaxation episodes and a decreased lower esophageal sphincter pressure are the main mechanisms involved. Currently used drugs are efficient on reflux symptoms, but only as long as they are administered, because they do not modify the reflux barrier. Certain nutrients or foods are generally considered to increase the frequency of gastroesophageal reflux symptoms, therefore physicians recommend changes in diet and some patients avoid bothering foods. This review summarizes current knowledge regarding food and gastroesophageal reflux. For example, fat intake increases the perception of reflux symptoms. Regular coffee and chocolate induce gastroesophageal reflux and increase the lower esophageal exposure to acid. Spicy foods might induce heartburn, but the exact mechanism is not known. Beer and wine induce gastroesophageal reflux, mainly in the first hour after intake. For other foods, like fried food or carbonated beverages data on gastroesophageal reflux is scarce. Similarly, there are few data about the type of diet and gastroesophageal reflux. Mediterranean diet and a very low carbohydrate diet protect against reflux. Regarding diet-related practices, consistent data showed that a "short-meal-to-sleep interval" favors reflux episodes, therefore some authors recommend that dinner should be at least four hours before bedtime. All these recommendations should consider patient's weight, because several meta-analyses showed a positive association between increased body mass index and gastroesophageal reflux disease.

Association of whole grain, refined grain, and cereal consumption with gastric cancer risk: A meta-analysis of observational studies

Many studies have analyzed the relationship between cereal, whole, or refined grain and the risk of gastric cancer (GC) and have yielded mixed results. Therefore, we performed a meta-analysis of observational studies to summarize the available evidence on this topic. Databases such as PubMed, EMBASE, Web of Science, MEDLINE, and the Cochrane Library were searched for studies focusing on these associations from inception to October 2017. Summary odd ratios (OR) and 95% confidence intervals (CI) were calculated by using either a random- or fixed-effect model according to the between-studies heterogeneity. Subgroup analysis was also performed. In total, eleven studies that included 530,176 participants were identified. In a pooled analysis of all studies, cereal exposure was not associated with GC risk (OR, 1.11, 95%CI, 0.85-1.36). Specific analyses indicated that whole grain consumption was associated with decreased GC risk (OR, 0.61, 95%CI, 0.40-0.83) and that refined grain consumption was associated with increased GC risk (OR, 1.65, 95%CI, 1.36-1.94). Higher whole grain and lower refined grain intake but not cereal consumption reduces GC risk. This study has been registered at ClinicalTrials.gov (ID: NCT03419663).

Dietary inflammatory index and risk of oesophageal cancer in Xinjiang Uyghur Autonomous Region, China

Diet has been shown to have an effect on both inflammation and oesophageal cancer. This study investigated the association between the dietary inflammatory index (DII®) and the risk of oesophageal cancer in Xinjiang Uyghur Autonomous Region, China. A case-control study was conducted during 2008-2009 in Urumqi and Shihezi. DII scores were calculated based on dietary intake assessed by a validated FFQ administered to 359 incident oesophageal cancer patients and 380 hospital-based controls. Higher DII scores indicate more pro-inflammatory diets. Logistic regression analyses were performed to assess the association between DII scores and oesophageal cancer risk. Oesophageal cancer patients had a significantly higher median DII score (-0·35; interquartile range (IQR)=-2·25, 1·86) than that of controls (-1·41; IQR -3·07, 0·40). Multivariable logistic analysis revealed a positive association between higher DII scores and oesophageal cancer risk (ORQuartile 4 v. 1 2·55; 95 % CI 1·61, 4·06; P trend<0·001). A pro-inflammatory diet appears to be associated with an increased risk of oesophageal cancer in Xinjiang Uyghur Autonomous Region. Specific carcinogenic mechanisms are discussed. Accumulating evidence, to which the study contributes, indicates that encouraging the intake of more anti-inflammatory foods may be a strategy to protect against oesophageal cancer in this high-risk area of China.

Different effects of dietary factors on reflux esophagitis and non-erosive reflux disease in 11,690 Korean subjects

BACKGROUND

Although dietary factors seem to be associated with gastroesophageal reflux symptoms, their effects on reflux esophagitis and non-erosive reflux disease (NERD) are unclear. We evaluate dietary effects on NERD and reflux esophagitis.

METHODS

A total of 11,690 health check-up persons completed questionnaires for reflux symptoms and 3-day recordings for dietary intake and underwent esophagogastroduodenoscopy from 2004 to 2008. Multiple logistic regression with odds ratio (OR) and 95% confidence interval (CI) was used to evaluate the relationship of dietary components with NERD or reflux esophagitis.

RESULTS

Prevalence of NERD and reflux esophagitis was 7.7 and 7.2%, respectively. In adjusted analysis, highest quartile of beans (OR 0.78, 95% CI 0.64-0.95), 3rd quartile of vegetables (OR 0.74, 95% CI 0.60-0.91), 4th quartile of fruit (OR 0.78, 95% CI 0.64-0.95), 4th quartile of egg (OR 0.78, 95% CI 0.64-0.96), and 3rd quartile of fish (OR 0.80, 95% CI 0.66-0.98), and 4th quartile of milk (OR 0.78, 95% CI 0.65-0.94) reduced NERD. Reflux esophagitis had no association with food groups, whereas it was related with men, absence of H. pylori, hiatal hernia, BMI, and total energy intake. Furthermore, dietary effect on NERD was similar in men and women, whereas highest tertile of potato (OR 1.91) and milk (OR 1.87) increased reflux esophagitis only in women.

CONCLUSIONS

While many food groups affected NERD, reflux esophagitis was associated with BMI and total energy intake rather than dietary component. These results may suggest different approaches toward dietary management of NERD and reflux esophagitis.

Dietary Inflammatory Index and Risk of Esophageal Squamous Cell Cancer in a Case-Control Study from Iran

Diet and inflammation have been suggested to be important risk factors for esophageal squamous cell carcinoma (ESCC). In this study, we examined the ability of the dietary inflammatory index (DII) to predict ESCC in a case-control study conducted in Iran. This study included 47 ESCC cases and 96 controls hospitalized for acute nonneoplastic diseases. The DII was computed based on dietary intake assessed by a previously validated food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) adjusted for age, energy, sex, body mass index, years of education, physical activity, smoking and gastroesophageal reflux. Subjects with higher DII scores (i.e., with a more proinflammatory diet) had a higher risk of ESCC, with the DII being used as both a continuous variable [ORcontinuous = 3.58, 95% confidence interval (CI): 1.76-7.26; one unit increase corresponding to ≈16% of its range in the current study] and a categorical variable (ORdii>1.20 vs ≤1.20 = 8.24, 95% CI: 2.03-33.47). These results indicate that a proinflammatory diet is associated with increased risk of ESCC.

Dietary inflammatory index and risk of esophageal squamous cell cancer in a case-control study from Italy

PURPOSE

Diet and inflammation have been suggested to be important risk factors for esophageal squamous cell cancer (ESCC). In this study, we examined the association between the dietary inflammatory index (DII) and ESCC in a case-control study conducted between 1992 and 1997 in Italy.

METHODS

This study included 304 ESCC cases and 743 controls hospitalized for acute non-neoplastic diseases. The DII was computed based on dietary intake assessed by a reproducible and valid 78-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) conditioned on age, sex, year of interview, and area of residence and adjusted for education, smoking, alcohol drinking, BMI, physical activity, and aspirin use. Energy adjustment was performed using the residual method.

RESULTS

Subjects with higher DII scores (i.e., with a more pro-inflammatory diet) had a higher risk of ESCC, with the DII being used as both a continuous variable (ORcontinuous 1.39, 95 % confidence interval, CI, 1.25-1.54; one-unit increase corresponding to ≈12 % of its range in the current study) and a categorical variable (ORquintile5vs1 2.46, 95 % CI 1.40-4.36; p trend < 0.001).

CONCLUSION

These results indicate that a pro-inflammatory diet is associated with a higher risk of ESCC, even after controlling for alcohol and tobacco exposure.

Diet-related inflammation and oesophageal cancer by histological type: a nationwide case-control study in Sweden

PURPOSE

This project sought to test the role of diet-related inflammation in modulating the risk of oesophageal cancer.

METHODS

A nationwide population-based case-control study was conducted from 1 December 1994 through 31 December 1997 in Sweden. All newly diagnosed patients with adenocarcinoma of the oesophagus or gastroesophageal junction and a randomly selected half of patients with oesophageal squamous cell carcinoma were eligible as cases. Using the Swedish Registry of the Total Population, the control group was randomly selected from the entire Swedish population and frequency-matched on age (within 10 years) and sex. The literature-derived dietary inflammatory index (DII) was developed to describe the inflammatory potential of diet. DII scores were computed based on a food frequency questionnaire. Higher DII scores indicate more pro-inflammatory diets. Odds ratios and 95 % confidence intervals (CI) were computed to assess risk associated between DII scores and oesophageal cancer using logistic regression adjusted by potential confounders.

RESULTS

In total, 189 oesophageal adenocarcinomas, 262 gastroesophageal junctional adenocarcinomas, 167 oesophageal squamous cell carcinomas, and 820 control subjects were recruited into the study. Significant associations with DII were observed for oesophageal squamous cell carcinoma (ORQuartile4vs1 4.35, 95 % CI 2.24, 8.43), oesophageal adenocarcinoma (ORQuartile4vs1 3.59, 95 % CI 1.87, 6.89), and gastroesophageal junctional adenocarcinoma (ORQuartile4vs1 2.04, 95 % CI 1.24, 3.36). Significant trends across quartiles of DII were observed for all subtypes of oesophageal cancer.

CONCLUSIONS

Diet-related inflammation appears to be associated with an increased risk of oesophageal cancer, regardless of histological type.

Macronutrient intake and stomach cancer

PURPOSE

This study examines the association between intake of selected macronutrients and the risk of stomach cancer in a Northern American population.

METHODS

Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces by 1,181 incident, histologically confirmed cases of stomach cancer and 5,039 population controls. Information on nutrient intake was obtained using a food frequency questionnaire. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived through unconditional logistic regression to adjust for potential confounders, including an estimate of total energy intake.

RESULTS

Intakes of total fat, saturated fat, and cholesterol were significantly associated with the risk of stomach cancer: The ORs for the highest versus the lowest quartile were 1.58 (95% CI 1.13-2.20), 1.86 (95% CI 1.37-2.52), and 1.75 (95% CI 1.36-2.25), respectively. Total fiber was inversely associated with stomach cancer (p = 0.03). The positive associations with intake of total fat and saturated fat were apparently stronger in women, overweight or obese subjects, and ever smokers. Saturated fat was specifically associated with increased risk of gastric cardia cancer, with an OR of 3.31 (95% CI 1.48-7.43).

CONCLUSIONS

A diet high in saturated fat appears to increase the risk of stomach cancer, particularly among obese subjects and for gastric cardia cancer.

A dietary pattern rich in lignans, quercetin and resveratrol decreases the risk of oesophageal cancer

Dietary lignans, quercetin and resveratrol have oestrogenic properties, and animal studies suggest that they synergistically decrease cancer risk. A protective effect of lignans on the development of oesophageal cancer in humans has recently been demonstrated, and the present study aimed to test whether these three phytochemicals synergistically decrease the risk of oesophageal cancer. Data from a Swedish nationwide population-based case-control study that recruited 181 cases of oesophageal adenocarcinoma (OAC), 158 cases of oesophageal squamous-cell carcinoma (OSCC), 255 cases of gastro-oesophageal junctional adenocarcinoma (JAC) and 806 controls were analysed. Exposure data were collected through face-to-face interviews and questionnaires. The intake of lignans, quercetin and resveratrol was assessed using a sixty-three-item FFQ. Reduced-rank regression was used to assess a dietary pattern, and a simplified dietary pattern score was categorised into quintiles on the basis of the distribution among the control subjects. Unconditional multivariable logistic regression provided OR with 95% CI, adjusted for all the potential risk factors. A dietary pattern rich in lignans, quercetin and resveratrol was mainly characterised by a high intake of tea, wine, lettuce, mixed vegetables, tomatoes, and whole-grain bread and a low intake of milk. There were dose-dependent associations between simplified dietary pattern scores and all types of oesophageal cancer (all P for trend < 0.05). On comparing the highest quintiles with the lowest, the adjusted OR were found to be 0.24 (95% CI 0.12, 0.49) for OAC, 0.31 (95% CI 0.15, 0.65) for OSCC, and 0.49 (95% CI 0.28, 0.84) for JAC. The results of the present study indicate that a dietary pattern characterised by the intake of lignans, quercetin and resveratrol may play a protective role in the development of oesophageal cancer in the Swedish population.

A case-control study of glycemic index, glycemic load and dietary fiber intake and risk of adenocarcinomas and squamous cell carcinomas of the esophagus: the Australian Cancer Study

Background

Glycemic index (GI) and glycemic load (GL) have been investigated as etiologic factors for some cancers, but epidemiological data on possible associations between dietary carbohydrate intake and esophageal cancer are scant. This study examined the association between GI, GL, and other dietary carbohydrate components and risk of adenocarcinomas and squamous cell carcinoma of the esophagus accounting for established risk factors.

Methods

We analyzed data from a population-based Australian case-control study (2002-05) comprising 299 adenocarcinoma (EAC), 337 gastro-esophageal junction adenocarcinoma (EGJAC), 245 squamous cell carcinoma (ESCC), and 1507 controls sampled from a population registry. Dietary information was obtained using a 135-item food frequency questionnaire (FFQ); GI and GL were derived from an Australian GI database. Multivariable logistic regression models were used to derive odds ratios (ORs).

Results

All three case groups tended to have a lower intake of fiber, and significantly higher intake of fat, total energy, and alcohol (ESCC only) compared to controls. GI was unrelated to all histological types. Higher GL was not associated with risk of EAC and EGJAC, but was inversely associated with risk of ESCC (adjusted model, p_trend = 0.006), specifically among men where we observed a 58% reduced risk of ESCC in the highest versus the lowest quartile. Increased intake of total carbohydrates and starch was related to similarly large risk reductions of ESCC. Fiber intake was strongly and inversely associated with risk of EAC, EGJAC and ESCC (all p_trend ≤0.001), indicating risk reductions of 28%-37% per 10 g/day.

Conclusions

This study suggests a reduced risk of esophageal SCC with higher GL level particularly in men, but provides no evidence for the role of GI in the development of esophageal cancer. In addition, increased fiber intake appears to be associated with lower risk of all histological types of esophageal cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-877) contains supplementary material, which is available to authorized users.

Diet and lifestyle factors and risk of subtypes of esophageal and gastric cancers: classification tree analysis

PURPOSE

Although risk factors for squamous cell carcinoma of the esophagus and adenocarcinomas of the esophagus (EA), gastric cardia (GC), and other (noncardia) gastric (OG) sites have been identified, little is known about interactions among risk factors. We sought to examine interactions of diet, other lifestyle, and medical factors with risks of subtypes of esophageal and gastric cancers.

METHODS

We used classification tree analysis to analyze data from a population-based case-control study (1095 cases, 687 controls) conducted in Connecticut, New Jersey, and western Washington State.

RESULTS

Frequency of reported gastroesophageal reflux disease symptoms was the most important risk stratification factor for EA, GC, and OG, with dietary factors (EA, OG), smoking (EA, GC), wine intake (GC, OG), age (OG), and income (OG) appearing to modify the risk of these cancer sites. For esophageal squamous cell carcinoma, smoking was the most important risk stratification factor, with gastroesophageal reflux disease, income, race, noncitrus fruit, and energy intakes further modifying risk.

CONCLUSION

Various combinations of risk factors appear to interact to affect risk of each cancer subtype. Replication of these data mining analyses are required before suggesting causal pathways; however, the classification tree results are useful in partitioning risk and mapping multilevel interactions among risk variables.

Optimal treatment of laryngopharyngeal reflux disease

Laryngopharyngeal reflux is defined as the reflux of gastric content into larynx and pharynx. A large number of data suggest the growing prevalence of laryngopharyngeal symptoms in patients with gastroesophageal reflux disease. However, laryngopharyngeal reflux is a multifactorial syndrome and gastroesophageal reflux disease is not the only cause involved in its pathogenesis. Current critical issues in diagnosing laryngopharyngeal reflux are many nonspecific laryngeal symptoms and signs, and poor sensitivity and specificity of all currently available diagnostic tests. Although it is a pragmatic clinical strategy to start with empiric trials of proton pump inhibitors, many patients with suspected laryngopharyngeal reflux have persistent symptoms despite maximal acid suppression therapy. Overall, there are scant conflicting results to assess the effect of reflux treatments (including dietary and lifestyle modification, medical treatment, antireflux surgery) on laryngopharyngeal reflux. The present review is aimed at critically discussing the current treatment options in patients with laryngopharyngeal reflux, and provides a perspective on the development of new therapies.

Dietary fibre intake associated with reduced risk of oesophageal cancer in Xinjiang, China

OBJECTIVE

To ascertain the relationship between dietary fibre intake and risk of oesophageal cancer in remote northwest China, where the cancer incidence is known to be high.

METHODS

A case-control study was conducted during 2008-2009 in the Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. Information on habitual foods consumption was obtained by face-to-face interview, from which dietary fibre intakes were estimated using the Chinese food composition tables.

RESULTS

The oesophageal cancer patients reported lower intake levels of total dietary fibre and fibre derived from vegetables and fruits than those of controls. Overall, regular intake of fibre was inversely associated with the oesophageal cancer risk, the adjusted odds ratio being 0.47 (95% confidence interval 0.32-0.69) for the highest (>27 g) versus the lowest (<16 g) tertile of daily intake, with a significant dose-response relationship (p=0.004). Similar reductions in risk were also apparent for high intake levels of vegetable fibre and fruit fibre, but to a lesser extent for cereal fibre.

CONCLUSION

Habitual intake of dietary fibre was associated with a reduced risk of oesophageal cancer for adults in northwest China.

Dietary fiber and the risk of precancerous lesions and cancer of the esophagus: a systematic review and meta-analysis

Dietary fiber has several anticarcinogenic effects and is thought to be protective against esophageal cancer. The aim of this systematic review was to quantify the association between dietary fiber and the risk of esophageal cancer by investigating histological subtypes of esophageal cancer and the stage at which fiber may influence the carcinogenic pathway. Systematic search strategies were used to identify relevant studies, and adjusted odds ratios (ORs) were combined using random-effects meta-analyses to assess the risk of cancer when comparing extreme categories of fiber intake. Ten relevant case-control studies were identified within the timeframe searched. Pooled estimates from eight studies of esophageal adenocarcinoma revealed a significant inverse association with the highest fiber intakes (OR 0.66; 95% confidence interval [CI] 0.44-0.98). Two studies also identified protective effects of dietary fiber against Barrett's esophagus. Similar, though nonsignificant, associations were observed when results from five studies of fiber intake and risk of squamous cell carcinoma were combined (OR 0.61; 95%CI 0.31-1.20). Dietary fiber is associated with protective effects against esophageal carcinogenesis, most notably esophageal adenocarcinoma. Potential methods of action include modification of gastroesophageal reflux and/or weight control.

Dietary fiber intake reduces risk for gastric cancer: a meta-analysis

BACKGROUND & AIMS

The association between dietary fiber intake and gastric cancer risk has been investigated by many studies, with inconclusive results. We conducted a meta-analysis of case-control and cohort studies to analyze this association.

METHODS

Relevant studies were identified by searching PubMed and Embase through October 2012. We analyzed 21 articles, which included 580,064 subjects. Random-effects models were used to estimate summary relative risks. Dose-response, subgroup, sensitivity, meta-regression, and publication bias analyses were performed.

RESULTS

The summary odds ratios of gastric cancer for the highest, compared with the lowest, dietary fiber intake was 0.58 (95% confidence interval, 0.49-0.67) with significant heterogeneity among studies (P < .001, I(2) = 62.2%). Stratified analysis for study design, geographic area, source and type of fiber, Lauren's classification, publication year, sample size, and quality score of study yielded consistent results. Dose-response analysis associated a 10-g/day increment in fiber intake with a significant (44%) reduction in gastric cancer risk. Sensitivity analysis restricted to studies with control for conventional risk factors produced similar results, and omission of any single study had little effect on the combined risk estimate.

CONCLUSIONS

In a meta-analysis, we show that dietary fiber intake is associated inversely with gastric cancer risk; the effect probably is independent of conventional risk factors. The direction of the protective association of dietary fiber was consistent among all studies, but the absolute magnitude was less certain because of heterogeneity among the studies. Further studies therefore are required to establish this association.

Variety in vegetable and fruit consumption and the risk of gastric and esophageal cancer in the European Prospective Investigation into Cancer and Nutrition

Diets high in vegetables and fruits have been suggested to be inversely associated with risk of gastric cancer. However, the evidence of the effect of variety of consumption is limited. We therefore investigated whether consumption of a variety of vegetables and fruit is associated with gastric and esophageal cancer in the European Prospective Investigation into Cancer and Nutrition study. Data on food consumption and follow-up on cancer incidence were available for 452,269 participants from 10 European countries. After a mean follow-up of 8.4 years, 475 cases of gastric and esophageal adenocarcinomas (180 noncardia, 185 cardia, gastric esophageal junction and esophagus, 110 not specified) and 98 esophageal squamous cell carcinomas were observed. Diet Diversity Scores were used to quantify the variety in vegetable and fruit consumption. We used multivariable Cox proportional hazard models to calculate risk ratios. Independent from quantity of consumption, variety in the consumption of vegetables and fruit combined and of fruit consumption alone were statistically significantly inversely associated with the risk of esophageal squamous cell carcinoma (continuous hazard ratio per 2 products increment 0.88; 95% CI 0.79-0.97 and 0.76; 95% CI 0.62-0.94, respectively) with the latter particularly seen in ever smokers. Variety in vegetable and/or fruit consumption was not associated with risk of gastric and esophageal adenocarcinomas. Independent from quantity of consumption, more variety in vegetable and fruit consumption combined and in fruit consumption alone may decrease the risk of esophageal squamous cell carcinoma. However, residual confounding by lifestyle factors cannot be excluded.

Wholegrain cereals and bread: a duet of the Mediterranean diet for the prevention of chronic diseases

OBJECTIVE

The promotion of healthy lifestyles is one of the major goals of governments and international agencies all over the world. Wholegrain cereals are rich in nutrients and many phytochemical compounds, with recognised benefits for health, including dietary fibre, a number of phenolic compounds, lignans, vitamins and minerals and other bioactive components. The aim of the present work is to review the fundamental studies that support the consumption of wholegrain cereals and bread to prevent chronic diseases.

DESIGN

Descriptive review considering human studies.

SETTING AND SUBJECTS

Subjects included in randomised intervention trials and cohort studies from different countries published up to 2010.

RESULTS

Several studies show consistently that subjects who ingest three or more portions of foods per day based on wholegrain cereals have a 20-30 % lower risk of CVD than subjects who ingest low quantities of cereals. This level of protection is not observed with the ingestion of refined cereals, these being even higher than with the intake of fruit and vegetables. Likewise, high intake of wholegrain cereals and their products, such as whole-wheat bread, is associated with a 20-30 % reduction in the risk of type 2 diabetes. Finally, protection against the risk of colorectal cancer and polyps, other cancers of the digestive tract, cancers related to hormones and pancreatic cancer has been associated with the regular consumption of wholegrain cereals and derived products.

CONCLUSIONS

The regular intake of wholegrain cereals can contribute to reduction of risk factors related to non-communicable chronic diseases.

Population based study to assess prevalence and risk factors of gastroesophageal reflux disease in a high altitude area

AIM

We did a population-based cross-sectional study to investigate the prevalence and risk factors of gastroesophageal reflux disease (GERD) in a high altitude area.

METHODS

An observational study using a validated questionnaire consisting of demographic, lifestyle and dietary characteristics was administered in an interview based format by two clinicians on a sample of adult population residing in urban area and rural high altitude areas of Ladakh. Presence of GERD was defined as a score of ≥4 using a previously validated symptom score based on the severity and frequency of heartburn and regurgitation. Other factors studied were body mass index (BMI), oxygen saturation levels by pulse oximetry and serum lipid profile. A multivariate analysis was done to find out risk factors for symptomatic GERD.

RESULTS

Of the 905 subjects analyzed, there were 399 (44.1%) men; 469 (51.8%) were from rural background and 722 (79.8%) lived in areas 3,000 m above sea level. Symptomatic GERD was present in 169 (18.7%) subjects. Regurgitation occurred once a week in 34.8% and heartburn occurred in 42.9% of subjects. Sixteen (9.5%) had moderate-severe disease activity while 153 (90.5%) had mild disease. Three hundred and eighty-eight (42.7%) and 315 (34.8%) subjects had symptom of heartburn and regurgitation (at least once a week), respectively. On multivariate analysis, risk factors for GERD were age ≤50 years (OR: 1.508, 95% CI: 1.028-2.213), sedentary lifestyle (OR: 2.78, 95% CI: 1.016-7.638), lower intake of salt tea (OR: 1.663, 95% CI: 1.014-2.726); whereas the protective factors were no intake of meat (OR: 0.841, 95% CI: 0.715-0.990), intake of fresh fruits ≥1/week (OR: 0.631, 95% CI: 0.409-0.973), and serum LDL ≤150 mg/dL (OR: 0.435, 95% CI: 0.218-0.868).

CONCLUSION

This population-based study in a high altitude area in India suggests a high prevalence (18.7%) of GERD. A younger age group, sedentary lifestyle, serum LDL >150 mg/dL, high consumption of meat, low consumption of salted tea and low consumption of fresh fruits were significant risk factors for development of GERD.

Principal component analysis of dietary and lifestyle patterns in relation to risk of subtypes of esophageal and gastric cancer

PURPOSE

To carry out pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers.

METHODS

We evaluated risk factors for esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and other gastric cancers (OGA) using data from a population-based case-control study conducted in Connecticut, New Jersey, and western Washington state. Dietary/lifestyle patterns were created using principal component analysis (PCA). Impact of the resultant scores on cancer risk was estimated through logistic regression.

RESULTS

PCA identified six patterns: meat/nitrite, fruit/vegetable, smoking/alcohol, legume/meat alternate, GERD/BMI, and fish/vitamin C. Risk of each cancer under study increased with rising meat/nitrite score. Risk of EA increased with increasing GERD/BMI score, and risk of ESCC rose with increasing smoking/alcohol score and decreasing gastroesophageal reflux disease (GERD)/body mass index (BMI) score. Fruit/vegetable scores were inversely associated with EA, ESCC, and GCA.

CONCLUSIONS

PCA may provide a useful approach for summarizing extensive dietary/lifestyle data into fewer interpretable combinations that discriminate between cancer cases and controls. The analyses suggest that meat/nitrite intake is associated with elevated risk of each cancer under study, whereas fruit/vegetable intake reduces risk of EA, ESCC, and GCA. GERD/obesity were confirmed as risk factors for EA and smoking/alcohol as risk factors for ESCC.

Intake of whole grains in Scandinavia is associated with healthy lifestyle, socio-economic and dietary factors

Objective

To identify the dietary, lifestyle and socio-economic factors associated with the intake of whole grains (WG) in Norway, Sweden and Denmark.

Design

A cross-sectional study.

Setting

Subsample of the Scandinavian cohort ‘HELGA’ consisting of three prospective cohorts: The Norwegian Women and Cancer Study; The Northern Sweden Health and Disease Study; and the Danish Diet, Cancer and Health Study.

Subjects

A total of 8702 men and women aged 30–65 years. Dietary data are from one 24 h dietary recall and data on socio-economic status and lifestyle factors including anthropometric values are from the baseline collection of data.

Results

Vegetables, fruits, dairy products, fish and shellfish, coffee, tea and margarine were directly associated with the intake of WG, whereas red meat, white bread, alcohol and cakes and biscuits were inversely associated. Smoking and BMI were consistently inversely associated with the intake of WG. Furthermore, length of education was directly associated with the intake of WG among women.

Conclusions

The intake of WG was found to be directly associated with healthy diet, lifestyle and socio-economic factors and inversely associated with less healthy factors, suggesting that these factors are important for consideration as potential confounders when studying WG intake and disease associations.

Barrett's esophagus, esophageal and esophagogastric junction adenocarcinomas: the role of diet

Identification of modifiable risk factors is an attractive approach to primary prevention of esophageal adenocarcinoma (EAC) and esophagogastric junction adenocarcinoma (EGJAC). We conducted a review of the literature to investigate the association between specific dietary components and the risk of Barrett’s esophagus (BE), EAC and EGJAC, supposing diet might be a risk factor for these tumors. Consumption of meat and high-fat meals has been found positively associated with EAC and EGJAC. An inverse association with increased intake of fruit, vegetables and antioxidants has been reported but this association was not consistent across all studies reviewed. Few studies have examined the association between diet and BE. Additional research is needed to confirm the aforementioned association and clarify the mechanisms by which dietary components affect the risk of developing EAC and EGJAC. Future studies could advance our knowledge by emphasizing prospective designs to reduce recall bias, by using validated dietary intake questionnaires and biological measures and by considering important confounders such as gastro-esophageal reflux disease (GERD) symptoms, tobacco and alcohol use, biometrics, physical activity, and socioeconomic factors.

Epidemiology of adenocarcinoma of the esophagus, gastric cardia, and upper gastric third

The incidence of adenocarcinoma of the esophagus and esophagogastric junction (gastric cardia) has risen rapidly over the past three decades in the United States and northern Europe. This increase had been most dramatic among White males. The majority of these cancers arise from Barrett's esophagus. However, less than 10% of the patients with esophageal adenocarcinoma were known to have Barrett's esophagus before. Current evidence indicates that gastroesophageal reflux and obesity are major risk factors for adenocarcinoma of the esophagus. Abdominal obesity, more prevalent in males, and independent of body mass index, seems to be associated with an increased risk of esophageal adenocarcinoma but not of cardia adenocarcinoma. This observation may explain the high male:female ratio observed in esophageal adenocarcinoma. Tobacco use has also been found as a possible risk factor for adenocarcinoma of the esophagus and gastric cardia. Infection with Helicobacter pylori and the use of nonsteroidal anti-inflammatory drugs might reduce the risk. On the other hand, low intake of fruits, vegetables, and cereal fibers seem to increase the risk of esophageal adenocarcinoma. Currently, there is no evidence that strongly supports any specific strategy to screen a subgroup of the population at risk for adenocarcinoma of the esophagus or esophagogastric junction. Future strategies to decrease obesity and tobacco use might help to reduce the burden of esophageal adenocarcinoma at least partially.

Dietary factors and the risks of oesophageal adenocarcinoma and Barrett's oesophagus

Incidence rates for oesophageal adenocarcinoma have increased by over 500% during the past few decades without clear reasons. Gastro-oesophageal reflux disease, obesity and smoking have been identified as risk factors, although the demographic distribution of these risk factors is not consistent with the demographic distribution of oesophageal adenocarcinoma, which is substantially more common among whites and males than any other demographic groups. Numerous epidemiological studies have suggested associations between dietary factors and the risks of oesophageal adenocarcinoma and its precursor, Barrett's oesophagus, though a comprehensive review is lacking. The main aim of the present review is to consider the evidence linking dietary factors with the risks of oesophageal adenocarcinoma, Barrett's oesophagus, and the progression from Barrett's oesophagus to oesophageal adenocarcinoma. The existing epidemiological evidence is strongest for an inverse relationship between intake of vitamin C, β-carotene, fruits and vegetables, particularly raw fruits and vegetables and dark green, leafy and cruciferous vegetables, carbohydrates, fibre and Fe and the risk of oesophageal adenocarcinoma and Barrett's oesophagus. Patients at higher risk for Barrett's oesophagus and oesophageal adenocarcinoma may benefit from increasing their consumption of fruits and vegetables and reducing their intake of red meat and other processed food items. Further research is needed to evaluate the relationship between diet and the progression of Barrett's oesophagus to oesophageal adenocarcinoma. Evidence from cohort studies will help determine whether randomised chemoprevention trials are warranted for the primary prevention of Barrett's oesophagus or its progression to cancer.

Effects of dietary fiber, fats, and meat intakes on the risk of Barrett's esophagus

Animal and human models suggest associations between fat intake, fiber intake, and the risk of esophageal adenocarcinoma. We evaluated whether these factors may act early in the carcinogenic pathway as a risk factor for Barrett's esophagus, a potentially premalignant precursor to esophageal adenocarcinoma using a case-control design within the Kaiser Permanente, Northern California population. Incident Barrett's esophagus cases (n = 296) were matched to persons with gastroesophageal reflux disease (GERD) (n = 308) and to population controls (n = 309). Higher intakes of omega-3-fatty-acids [cases vs. population controls; OR = 0.46, 95% CI = 0.22-0.97, 4th vs. 1st quartiles of intake], polyunsaturated fat, total fiber (OR = 0.34, 95% CI = 0.15-0.76), and fiber from fruits and vegetables (OR = 0.47 95% CI = 0.25-0.88) were associated with a lower risk of Barrett's esophagus. Higher meat intakes were associated with a lower risk of long-segment Barrett's esophagus (OR = 0.25, 95% CI = 0.09-0.72). In contrast, higher trans-fat intakes were associated with increased risk (OR = 1.11; 95% CI = 1.03-1.21 per g/day). Total fat intake, barbecued foods, and fiber intake from sources other than fruits and vegetables were not associated with Barrett's esophagus. Future studies to evaluate whether dietary interventions might influence the risk of Barrett's esophagus or esophageal adenocarcinoma in high risk persons are needed.

Pathology and pathobiology of the oesophageal carcinoma

Carcinoma of the oesophagus including carcinoma of gastro-oesophageal junction are rapidly increasing in incidence. During recent years there have been changes in the knowledge surrounding biology of the disease progression. Identification of dysplasia in mucosal biopsies is the most reliable pathologic indicator of an increased risk of development of squamous cell carcinoma and passes through the sequence of chronic esophagitis, low-grade and high-grade dysplasia and invasive carcinoma. Although Barrett's esophagus is a precursor to esophageal adenocarcinoma and have a well described sequence of carcinogenesis: the Barrett's metaplasia-dysplasia-adenocarcinoma sequence, not all patients with this disorder require intensive surveillance. The natural history of dysplasia is poorly understood, particularly in low-risk regions, and prospective follow-up studies are needed. Adjunctive methods to improve reproducibility, such as immunostaining for alpha-methylacyl-coenzyme A racemase (AMACR), show promise, but require confirmation in larger studies. In addition, several controversial methods such as detection of p16, p53, and DNA content abnormalities may help identify patients at particularly high risk for progression to cancer, but these techniques are not yet widely available for routine clinical application. More studies are needed to define other early nonmorphologic biomarkers for risk of squamous cell carcinoma. Recent evidence regarding the importance of several histopathologically derived prognostic factors, such as circumferential resection margin status and lymph node metastases are evaluated, including lymph node micrometastases and the sentinel node concept. With the rising use of multimodal treatments for oesophageal cancer it is important that the response of the tumour to this therapy can be carefully documented by histopathology.

Whole grains and human health

Epidemiological studies find that whole-grain intake is protective against cancer, CVD, diabetes, and obesity. Despite recommendations to consume three servings of whole grains daily, usual intake in Western countries is only about one serving/d. Whole grains are rich in nutrients and phytochemicals with known health benefits. Whole grains have high concentrations of dietary fibre, resistant starch, and oligosaccharides. Whole grains are rich in antioxidants including trace minerals and phenolic compounds and these compounds have been linked to disease prevention. Other protective compounds in whole grains include phytate, phyto-oestrogens such as lignan, plant stanols and sterols, and vitamins and minerals. Published whole-grain feeding studies report improvements in biomarkers with whole-grain consumption, such as weight loss, blood-lipid improvement, and antioxidant protection. Although it is difficult to separate the protective properties of whole grains from dietary fibre and other components, the disease protection seen from whole grains in prospective epidemiological studies far exceeds the protection from isolated nutrients and phytochemicals in whole grains.

Etiologic factors of gastric cardiac adenocarcinoma among men in Taiwan

AIM: To elucidate etiologic associations between Helicobacter pylori (H pylori), lifestyle, environmental factors and gastric cardiac adenocarcinoma (GCA) among men.

METHODS: A hospital-based case-control study was conducted in Taiwan from 2000 to 2009. All cases were newly confirmed as primary GCA. Five controls were selected matching with age, sex, and admission date to each case. Participants were informed of potential risk factors with a structured questionnaire by trained interviewers during hospitalization and provided a blood sample for the determination of H pylori infection. Odds ratio (OR) and 95% confidence interval (95% CI) were used to evaluate risk, and a multivariate conditional logistic regression model was performed.

RESULTS: All participants recruited for this study were men, consisting of 41 cases and 205 controls. Results of the univariate analysis showed that significant factors associated with the etiology of GCA included H pylori (OR = 2.69, 95% CI = 1.30-5.53), cigarette smoking (OR = 2.28, 95% CI = 1.05-4.96), working or exercising after meals (OR = 3.26, 95% CI = 1.31-8.11), salted food (OR = 2.51, 95%CI = 1.08-6.11), fresh vegetables (OR = 0.28, 95% CI = 0.09-0.80), fruits (OR = 0.19, 95% CI = 0.04-0.89), and rice as principal food (OR = 0.53, 95% CI = 0.30-0.85). Multivariate conditional logistic regression models indicated that a significantly elevated risk of contracting GCA was associated with working or exercising after meals (OR = 3.18, 95% CI = 1.23-9.36) and H pylori infection (OR = 2.93, 95% CI = 1.42-6.01). In contrast, the consumption of fresh vegetables (OR = 0.22, 95% CI = 0.06-0.83), fruits (OR = 0.28, 95% CI = 0.09-0.79) and rice as principal food (OR = 0.48, 95% CI = 0.24-0.93) remained as significant beneficial factor associated with GCA.

CONCLUSION: Working or exercising after meals and H pylori infection increase the risk of GCA, but higher intakes of rice, fresh vegetables and fruits reduce the risk.

The effect of strict adherence to a high-fiber, high-fruit and -vegetable, and low-fat eating pattern on adenoma recurrence

Individual differences in dietary intake are thought to account for substantial variation in cancer incidence. However, there has been a consistent lack of effect for low-fat, high-fiber dietary interventions and risk of colorectal cancer. These inconsistencies may reflect the multistage process of cancer as well as the range and timing of dietary change. Another potential reason for the lack of effect is poor dietary adherence among participants in these trials. The authors examined the effect of strict adherence to a low-fat, high-fiber, high-fruit and -vegetable intervention over 4 years among participants (n = 1,905) in the US Polyp Prevention Trial (1991-1998) on colorectal adenoma recurrence. There was a wide range of individual variation in the level of compliance among intervention participants. The most adherent participants, defined as "super compliers" (n = 210), consistently reported that they met or exceeded each of the 3 dietary goals at all 4 annual visits. Multivariate logistic regression models were used to estimate the association between dietary adherence and adenoma recurrence. The authors observed a 35% reduced odds of adenoma recurrence among super compliers compared with controls (odds ratio = 0.65, 95% confidence interval: 0.47, 0.92). Findings suggest that high compliance with a low-fat, high-fiber diet is associated with reduced risk of adenoma recurrence.

Diet and lifestyle modifications in the management of gastroesophageal reflux disease

Gastroesophageal reflux disease is a chronic condition affecting 44% of the American population at least once a month, with daily occurrences affecting about 7% of the population. It is the most common gastrointestinal-related diagnosis given by physicians during clinic visits in the United States. Treatment of this disease is a step-wise approach that includes diet and lifestyle interventions as well as medications titrated based on symptom severity. This article reviews dietary and lifestyle factors that contribute to the physiology and symptoms of gastroesophageal reflux disease and modification of these factors as an adjunctive therapy.

Glycemic index, carbohydrate and fiber intakes and risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma

OBJECTIVE

To examine the association between dietary glycemic index (GI), glycemic load (GL), total carbohydrate, sugars, starch, and fiber intakes and the risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma.

METHODS

In an all-Ireland study, dietary information was collected from patients with esophageal adenocarcinoma (n = 224), long-segment Barrett's esophagus (n = 220), reflux esophagitis (n = 219), and population-based controls (n = 256). Multiple logistic regression analysis examined the association between dietary variables and disease risk by tertiles of intake and as continuous variables, while adjusting for potential confounders.

RESULTS

Reflux esophagitis risk was positively associated with starch intake and negatively associated with sugar intake. Barrett's esophagus risk was significantly reduced in people in the highest versus the lowest tertile of fiber intake (OR 0.44 95%CI 0.25-0.80). Fiber intake was also associated with a reduced risk of esophageal adenocarcinoma, as was total carbohydrate intake (OR 0.45 95%CI 0.33-0.61 per 50 g/d increase). However, an increased esophageal adenocarcinoma risk was detected per 10 unit increase in GI intake (OR 1.42 95%CI 1.07-1.89).

CONCLUSIONS

Our findings suggest that fiber intake is inversely associated with Barrett's esophagus and esophageal adenocarcinoma risk. Esophageal adenocarcinoma risk is inversely associated with total carbohydrate consumption but positively associated with high GI intakes.

Food group intake and risk of subtypes of esophageal and gastric cancer

Incidence rates for adenocarcinomas of the esophagus and gastric cardia have been increasing rapidly, while rates for non-cardia gastric adenocarcinoma and esophageal squamous cell carcinoma have declined. We examined food group intake as a risk factor for subtypes of esophageal and gastric cancers in a multicenter, population-based case-control study in Connecticut, New Jersey and western Washington state. Associations between food groups and risk were estimated using adjusted odds ratios (OR), based on increasing intake of one serving per day. Total vegetable intake was associated with decreased risk of esophageal adenocarcinoma (OR = 0.85, 95% CI = 0.75, 0.96). Conversely, total meat intake was associated with increased risk of esophageal adenocarcinoma (OR = 1.43, 95% CI = 1.11, 1.83), gastric cardia adenocarcinoma (OR = 1.37, 95% CI = 1.08, 1.73) and noncardia gastric adenocarcinoma (OR = 1.39, 95% CI = 1.12, 1.71), with red meat most strongly associated with esophageal adenocarcinoma risk (OR = 2.49, 95% CI = 1.39, 4.46). Poultry was most strongly associated with gastric cardia adenocarcinoma (OR = 1.89, 95% CI = 1.15, 3.11) and noncardia gastric adenocarcinoma (OR = 1.90, 95% CI = 1.19, 3.03). High-fat dairy was associated with increased risk of both esophageal and gastric cardia adenocarcinoma. Higher intake of meats, particularly red meats, and lower intake of vegetables were associated with an increased risk of esophageal adenocarcinoma, while higher intake of meats, particularly poultry, and high-fat dairy was associated with increased risk of gastric cardia adenocarcinoma.

Carbohydrates and cancer: an overview of the epidemiological evidence

OBJECTIVE

To assess the epidemiological evidence on dietary carbohydrates and the risk of developing cancer.

METHOD

Review of published studies, concentrating on recent systematic reviews, meta-analyses and large prospective studies.

CONCLUSIONS

Carbohydrates have not been intensively investigated in epidemiological studies of diet and cancer. There is a moderately large amount of data on the possible association between dietary fibre and the risk for colorectal cancer; the results of studies have varied and no firm conclusion can be drawn, but the available data suggest that high intakes of dietary fibre possibly reduce the risk for colorectal cancer. There are also limited data which suggest that high intakes of sucrose might increase the risk for colorectal cancer and that high intakes of lactose might increase the risk for ovarian cancer. For other components of carbohydrates and other types of cancer, the available data are too sparse to draw even tentative conclusions. Further research is needed on the possible associations of carbohydrates with cancer risk.

Fiber intake and risk of adenocarcinomas of the esophagus and stomach

BACKGROUND

Since the 1970s, incidence rates for esophageal and gastric cardia adenocarcinomas have risen substantially for reasons that are not well understood. We sought to determine the role of dietary factors in these tumor types.

METHODS

This analysis on dietary factors included 206 esophageal adenocarcinoma, 257 gastric cardia, 366 distal gastric adenocarcinoma patients and, 1,308 control subjects from a population-based, case-control study conducted in Los Angeles County. Polytomous logistic regression was used to calculate odds ratios (ORs), as an estimate of the relative risk, and corresponding 95% confidence intervals (CIs) for the three tumor types.

RESULTS

Intake of fiber had a significant impact on risk of esophageal and gastric cardia adenocarcinoma after adjustment for age, gender, race, birthplace, education, cigarette smoking, body size, history of reflux, and vitamin use. Compared to subjects in the lowest quartile of fiber intake, subjects in the highest quartile of intake showed odd ratios of 0.44 (95% CI = 0.26-0.76) for esophageal adenocarcinoma (P trend = 0.004) and 0.58 (95% CI = 0.38-0.88) for gastric cardia adenocarcinoma (P trend = 0.016); these inverse associations remained after further adjustment for intake of fat. Positive associations between dietary fat and the three tumor types weakened after adjustment for fiber intake and were no longer statistically significant. For distal gastric cancer, a significant inverse association with fiber was observed only after adjustment for fat intake. The significant inverse associations with fiber remained after further adjustment for H. pylori infection for all three tumor types.

CONCLUSIONS

High intake of fiber was associated with significant reduced risks of esophageal and gastric cardia adenocarcinoma even after adjustment for dietary fat, H. pylori infection and other covariates.