Low-fat, high fruit and vegetable diets and weight loss do not affect biomarkers of cellular proliferation in Barrett esophagus

Immunity Depletion, Telomere Imbalance, and Cancer-Associated Metabolism Pathway Aberrations in Intestinal Mucosa upon Short-Term Caloric Restriction

Systems cancer biology analysis of calorie restriction (CR) mechanisms and pathways has not been carried out, leaving therapeutic benefits unclear. Using metadata analysis, we studied gene expression changes in normal mouse duodenum mucosa (DM) response to short-term (2-weeks) 25% CR as a biological model. Our results indicate cancer-associated genes consist of 26% of 467 CR responding differential expressed genes (DEGs). The DEGs were enriched with over-expressed cell cycle, oncogenes, and metabolic reprogramming pathways that determine tissue-specific tumorigenesis, cancer, and stem cell activation; tumor suppressors and apoptosis genes were under-expressed. DEG enrichments suggest telomeric maintenance misbalance and metabolic pathway activation playing dual (anti-cancer and pro-oncogenic) roles. The aberrant DEG profile of DM epithelial cells is found within CR-induced overexpression of Paneth cells and is coordinated significantly across GI tract tissues mucosa. Immune system genes (ISGs) consist of 37% of the total DEGs; the majority of ISGs are suppressed, including cell-autonomous immunity and tumor-immune surveillance. CR induces metabolic reprogramming, suppressing immune mechanics and activating oncogenic pathways. We introduce and argue for our network pro-oncogenic model of the mucosa multicellular tissue response to CR leading to aberrant transcription and pre-malignant states. These findings change the paradigm regarding CR's anti-cancer role, initiating specific treatment target development. This will aid future work to define critical oncogenic pathways preceding intestinal lesion development and biomarkers for earlier adenoma and colorectal cancer detection.

Randomized trial of weight loss in primary breast cancer: Impact on body composition, circulating biomarkers and tumor characteristics

Obesity adversely impacts overall and cancer‐specific survival among breast cancer patients. Preclinical studies demonstrate negative energy balance inhibits cancer progression; however, feasibility and effects in patients are unknown. A two‐arm, single‐blinded, randomized controlled weight‐loss trial was undertaken presurgery among 32 overweight/obese, Stage 0–II breast cancer patients. The attention control arm (AC) received basic nutritional counseling and upper‐body progressive resistance training whereas the weight loss intervention (WLI) arm received identical guidance, plus counseling on caloric restriction and aerobic exercise to promote 0.68–0.92 kg/week weight loss. Anthropometrics, body composition, blood and survey data were collected at baseline and presurgery ∼30 days later. Tumor markers (e.g., Ki67) and gene expression were assessed on biopsy and surgical specimens; sera were analyzed for cytokines, growth and metabolic factors. Significant WLI vs. AC differences were seen in baseline‐to‐follow‐up changes in weight (−3.62 vs. −0.52 kg), %body fat (−1.3 vs. 0%), moderate‐to‐vigorous physical activity (+224 vs. +115 min/week), caloric density (−0.3 vs. 0 kcal/g), serum leptin (−12.3 vs. −4.0 ng/dl) and upregulation of tumor PI3Kinase signaling and cell cycle‐apoptosis related genes (CC‐ARG; all p‐values <0.05). Cytolytic CD56^dimNK cell expression was positively associated with weight loss; CC‐ARG increased with physical activity. Increased tumor (nuclear) TNFα and IL‐1β, CX3CL1 and CXCL1 gene expression was observed in the WLI. Tumor Ki67 did not differ between arms. Feasibility benchmarks included 80% accrual, 100% retention, no adverse effects and excellent adherence. Short‐term weight loss interventions are feasible; however, mixed effects on tumor biology suggest unclear benefit to presurgical caloric restriction, but possible benefits of physical activity.

What's new?

Obesity adversely impacts survival among breast cancer patients. Preclinical studies demonstrate negative energy balance inhibits cancer progression; however, effects in patients are unknown. This is the first randomized controlled trial to assess the impact of a pre‐surgical weight loss intervention among early‐stage breast cancer patients. Results show the effects of acute negative energy balance on tumor biology, circulating biomarkers, and quality‐of‐life. Short‐term weight loss interventions are feasible; however, mixed effects on tumor biology suggest unclear benefit to pre‐surgical caloric restriction. Such interventions may be better timed after surgical resection, though cell cycle‐apoptosis and DNA damage‐repair scores support increasing physical activity.

A phase I pilot study evaluating the beneficial effects of black raspberries in patients with Barrett's esophagus

Black raspberries inhibit a broad range of cancers in preclinical models which has led to clinical evaluations targeting premalignant lesions of the colon, oral cavity and esophagus. A phase I pilot study was conducted in twenty Barrett's esophagus (BE) patients to investigate the effect of lyophilized black raspberries (LBR) on urinary metabolites and markers of lipid peroxidation, DNA damage and tissue markers of cellular proliferation, detoxification, and inflammation. Surveys, biopsies, blood and urine samples were collected before and after 6 months of LBR treatment (32 or 45 g). LBR significantly reduced urinary excretion of 8-epi-prostaglandin F2α, a marker of lipid peroxidation linked to oxidative stress and free radical damage. Urinary levels of the ellagitannin metabolites, urolithin A-glucuronide, urolithin A-sulfate and dimethylellagic acid glucuronide were significantly increased following 12 and 26 weeks of LBR consumption and may prove useful as indicators of compliance in future clinical studies. Immunohistochemical staining of BE biopsies following LBR treatment showed significant increases in mean GST-pi levels, with 55.6% of subjects responding favorably. In summary, LBR significantly decreased urinary lipid peroxidation levels and significantly increased GST-pi, a marker of detoxification, in BE epithelium. Still, LBR may need to be formulated differently, administered at higher concentrations or multiple times a day to increase efficacy.

Presurgical weight loss affects tumour traits and circulating biomarkers in men with prostate cancer

Background:

Obesity is associated with aggressive prostate cancer. To explore whether weight loss favourably affects tumour biology and other outcomes, we undertook a presurgical trial among overweight and obese men with prostate cancer.

Methods:

This single-blinded, two-arm randomised controlled trial explored outcomes of a presurgical weight loss intervention (WLI) that promoted ∼1 kg per week loss via caloric restriction and increased physical activity (PA). Forty overweight/obese men with clinically confirmed prostate cancer were randomised to the WLI presurgery or to a control arm; changes in weight, body composition, quality-of-life, circulating biomarkers, gene expression, and immunohistochemical markers in tumour and benign prostatic tissue were evaluated.

Results:

The study period averaged 50 days. Mean (s.d.) change scores for the WLI vs control arms were as follows: weight: −4.7 (3.1) kg vs −2.2 (4.4) kg (P=0.0508); caloric intake: −500 (636) vs −159 (600) kcal per day (P=0.0034); PA: +0.9 (3.1) vs +1.7 (4.6) MET-hours per day (NS); vitality: +5.3 (7.l4) vs −1.8 (8.1) (P=0.0491); testosterone: +55.1 (86.0) vs −48.3 (203.7) ng dl⁻¹ (P=0.0418); sex hormone-binding globulin: +14.0 (14.6) vs +1.8 (7.6) nmol l⁻¹ (P=0.0023); and leptin: −2.16 (2.6) vs −0.03 (3.75) (P=0.0355). Follow-up Ki67 was significantly higher in WLI vs control arms; median (interquartile range): 5.0 (2.5,10.0) vs 0.0 (0.0,2.5) (P=0.0061) and several genes were upregulated, for example, CTSL, GSK3B, MED12, and LAMC2.

Conclusions:

Intentional weight loss shows mixed effects on circulating biomarkers, tumour gene expression, and proliferative markers. More study is needed before recommending weight loss, in particular rapid weight loss, among men with prostate cancer.

Quantitation of spatial and temporal variability of biomarkers for Barrett's Esophagus

Chemoprevention and risk-stratification studies in Barrett's esophagus (BE) rely on biomarkers but the variability in their temporal and spatial expression is unknown. If such variability exists, it will impact sampling techniques and sample size calculations. Specimens from three levels of biopsies over two serial endoscopies in nondysplastic BE patients were analyzed for aneuploidy, proliferation markers (Ki67, Mcm2), and cell cycle markers (cyclin A and cyclin D1). A modification of the image cytometry technique, where cytokeratin staining automatically distinguished epithelial and stromal cells, measured aneuploidy on whole tissue sections. Other biomarkers were studied by immunohistochemistry. Coefficient of variability (SD/mean) was calculated; a value <10% indicated low variability. A total of 120 specimens (20 subjects each with three biopsy levels at two time points) from nondysplastic BE patients (71 ± 8.8 years, all Caucasian, 90% males, C5.1M7.5 ± 3.4 cm) were analyzed. The mean interval between endoscopies was 32.8 ± 8.4 months. Aneuploidy had a spatial variability of 6.8% at visit 1 (mean diploid index: 1.1 ± 0.09) and 7.9% at visit 2 (mean diploid index: 1.1 ± 0.06) and a temporal variability of 7.0-8.1% for the three levels. For other biomarkers, the spatial variability ranged from ∼5 to 30% at visit 1 and 11-92% at visit 2 and the temporal variability ranged from 0 to 77%. To conclude, of all the biomarkers, only aneuploidy had both spatial and temporal variability of <10%. Spatial and temporal variability were biomarker dependent and could be as high as 90% even without progression. These data will be useful to design chemoprevention and risk-stratification studies in BE.

Influence of body mass index on the prevalence and progression of dysplasia in Barrett's esophagus: a retrospective analysis (.)

OBJECTIVE

High body mass index (BMI) is a risk factor for Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Our aim was to determine if prevalence of dysplasia in BE varies by BMI and study the effect of BMI on progression to high-grade dysplasia (HGD) or EAC.

MATERIALS AND METHODS

This is a retrospective review of patients with endoscopic evidence of BE confirmed by presence of intestinal metaplasia on histology from January 2000 to December 2012 at Cleveland Clinic. Patient demographics, BMI and endoscopic findings such as length of BE, dysplasia in BE and size of hiatal hernia were reviewed. Dysplasia was classified as no dysplasia (NDBE), low-grade dysplasia (LGD), HGD and EAC.

RESULTS

In this cohort of 1239 patients, average BMI was 29.8 ± 6 kg/m(2). There were 228 (18.4%) in group with BMI <25, 236 (19%) in BMI group 25-27.4, 262 (21.1%) in BMI 27.5-29.9, 303 (24.5%) in BMI 30-34.9, 126 (10.2%) in BMI 35-39.9 and 86 (6.8%) in BMI ≥40. Lower BMI groups had lower prevalence of dysplasia while higher BMI groups had higher prevalence of dysplasia (p = 0.002). During mean follow up of 31.6 ± 26 months, there were 14 cases of HGD/EAC in NDBE group and 29 cases of HGD/EAC in LGD group. BMI or BMI change was not associated with progression to HGD/EAC in NDBE.

CONCLUSIONS

High BMI was associated with higher prevalence of dysplasia in BE. But once in a surveillance program, higher BMI is not associated with progression of dysplasia in NDBE.

Surrogate Markers: Lessons from the Next Gen?

The article by Banerjee and colleagues published in this issue of the journal involving a randomized control prevention trial of ursodeoxycholic acid (UDCA) in Barrett esophagus reported a null outcome despite being well designed and executed. Possible reasons for this null outcome are discussed focusing on use of surrogate endpoints in the trial. The trial is especially topical because it comes at a time when there are calls for a Pre-Cancer Genome Atlas (PCGA) for "understanding the earliest molecular and cellular events associated with cancer initiation…" This commentary discusses current concepts in prevention research including branched evolution that leads to therapeutic resistance. Length bias sampling postulates underdiagnosis is due to rapidly progressing disease that is difficult to detect by screening because it progresses to cancer too rapidly and that overdiagnosis is the result of very slowly or nonprogressing disease that is easy to detect by screening because it persists for a lifetime and the patient dies of unrelated causes. Finally, it also explores study designs, including surrogate endpoints in Barrett esophagus trials, and opportunities and pitfalls for a PCGA in the context of high levels of over and underdiagnosis of Barrett esophagus as well as many other cancers and their precursors. Cancer Prev Res; 9(7); 512-7. ©2016 AACRSee related article by Banerjee, et al., p. 528.

Prevention strategies for esophageal cancer: Perspectives of the East vs. West

Esophageal cancer is the eighth most common cancer worldwide. Esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) are the two major phenotypes in Western and Eastern countries, respectively. Because of different pathways in carcinogenesis, the risk factors and effective steps for prevention of esophageal cancer are different between EAC and ESCC. The carcinogenesis of EAC is initiated by the acid exposure of the esophageal mucosa from stomach while that of the ESCC are related to the chronic irritation of carcinogens mainly by the alcohol, cigarette, betel quid, and hot beverage. To eliminate the burden of esophageal cancer on the global health, the effective strategy should be composed of the primary, secondary, and tertiary prevention. In this article, we perform a systematic review of the preventive strategies for esophageal cancer with special emphasis on the differences from the perspectives of Western and Eastern countries.

Effect of low-fat diet interventions versus other diet interventions on long-term weight change in adults: a systematic review and meta-analysis

BACKGROUND

The effectiveness of low-fat diets for long-term weight loss has been debated for decades, with many randomised controlled trials (RCTs) and recent reviews giving mixed results. We aimed to summarise the large body of evidence from RCTs to determine whether low-fat diets contribute to greater weight loss than participants' usual diet, low-carbohydrate diets, and other higher-fat dietary interventions.

METHODS

We did a systematic review and random effects meta-analysis of RCTs comparing the long-term effect (≥1 year) of low-fat and higher-fat dietary interventions on weight loss by searching MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Cochrane Database of Systematic Reviews to identify eligible trials published from database inception up until July 31, 2014. We excluded trials if one intervention group included a non-dietary weight loss component but the other did not, and trials of dietary supplements or meal replacement drink interventions. Data including the main outcome measure of mean difference in weight change between interventions, and whether interventions were intended to lead to weight loss, weight maintenance, or neither, were extracted from published reports. We estimated the pooled weighted mean difference (WMD) with a DerSimonian and Laird random effects method.

FINDINGS

3517 citations were identified by the search and 53 studies met our inclusion criteria, including 68 128 participants (69 comparisons). In weight loss trials, low-carbohydrate interventions led to significantly greater weight loss than did low-fat interventions (18 comparisons; WMD 1·15 kg [95% CI 0·52 to 1·79]; I(2)=10%). Low-fat interventions did not lead to differences in weight change compared with other higher-fat weight loss interventions (19 comparisons; WMD 0·36 kg [-0·66 to 1·37; I(2)=82%), and led to a greater weight decrease only when compared with a usual diet (eight comparisons; -5·41 kg [-7·29 to -3·54]; I(2)=68%). Similarly, results of non-weight-loss trials and weight maintenance trials, for which no low-carbohydrate comparisons were made, showed that low-fat versus higher-fat interventions have a similar effect on weight loss, and that low-fat interventions led to greater weight loss only when compared with usual diet. In weight loss trials, higher-fat weight loss interventions led to significantly greater weight loss than low-fat interventions when groups differed by more than 5% of calories obtained from fat at follow-up (18 comparisons; WMD 1·04 kg [95% CI 0·06 to 2·03]; I(2)=78%), and when the difference in serum triglycerides between the two interventions at follow-up was at least 0·06 mmol/L (17 comparisons; 1·38 kg [0·50 to 2·25]; I(2)=62%).

INTERPRETATION

These findings suggest that the long-term effect of low-fat diet intervention on bodyweight depends on the intensity of the intervention in the comparison group. When compared with dietary interventions of similar intensity, evidence from RCTs does not support low-fat diets over other dietary interventions for long-term weight loss.

FUNDING

National Institutes of Health and American Diabetes Association.

The feasibility of an exercise intervention in males at risk of oesophageal adenocarcinoma: a randomized controlled trial

Objective

To investigate the feasibility and safety of a 24-week exercise intervention, compared to control, in males with Barrett’s oesophagus, and to estimate the effect of the intervention, compared to control, on risk factors associated with oesophageal adenocarcinoma development.

Methods

A randomized controlled trial of an exercise intervention (60 minutes moderate-intensity aerobic and resistance exercise five days/week over 24 weeks; one supervised and four unsupervised sessions) versus attention control (45 minutes stretching five days/week over 24 weeks; one supervised and four unsupervised sessions) in inactive, overweight/obese (25.0–34.9 kg/m²) males with Barrett’s oesophagus, aged 18–70 years. Primary outcomes were obesity-associated hormones relevant to oesophageal adenocarcinoma risk (circulating concentrations of leptin, adiponectin, interleukin-6, tumour necrosis factor-alpha, C-reactive protein, and insulin resistance [HOMA]). Secondary outcomes included waist circumference, body composition, fitness, strength and gastro-oesophageal reflux symptoms. Outcomes were measured at baseline and 24-weeks. Intervention effects were analysed using generalised linear models, adjusting for baseline value.

Results

Recruitment was difficult in this population with a total of 33 participants recruited (target sample size: n = 80); 97% retention at 24-weeks. Adherence to the exercise protocol was moderate. No serious adverse events were reported. A statistically significant intervention effect (exercise minus control) was observed for waist circumference (-4.5 [95% CI -7.5, -1.4] cm; p < 0.01). Effects on primary outcomes were not statistically significant.

Conclusion

This small, exploratory trial provides important information to inform future trial development including recruitment rates and estimates of effect sizes on outcomes related to oesophageal adenocarcinoma risk. Future trials should investigate a combined dietary and exercise intervention to achieve greater weight loss in this population and relax inclusion criteria to maximize recruitment.

Trial Registration

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12609000401257

Dietary intake of vegetables, folate, and antioxidants and the risk of Barrett's esophagus

PURPOSE

Diet is a potentially modifiable risk factor for Barrett's esophagus (BE). We investigated the associations between intakes of fruits and vegetables and risk of BE.

METHODS

We identified study subjects from 1,859 participants who underwent the endoscopy in a single VA Medical Center in the US between 2008 and 2011. Dietary intake in the previous year was elicited using a self-administered Block food frequency questionnaire (FFQ). Logistic regression model was used to estimate odds ratio (OR) and its 95 % confidence interval (CI) for BE.

RESULTS

A total of 151 cases with definite BE and 777 controls completed the FFQ. When highest tertile of intake was compared with the lowest, the OR (95 % CI) was 0.46 (0.26-0.81) for dark green vegetables, 0.52 (0.30-0.90) for legumes, 0.50 (0.28-0.90) for total fiber, 0.45 (0.25-0.81) for isoflavones, 0.52 (0.30-0.67) for total folate, and 0.45 (0.26-0.79) for lutein, adjusting for multiple confounding factors including use of aspirin or proton pump inhibitor, gastro-esophageal reflux symptoms, and physical activity. The association for dark green vegetables was attenuated after adjustment for lutein, total fiber, and total folate (OR = 0.82; 95 % CI 0.30-2.22).

CONCLUSION

Higher intake of dark green vegetables was associated with a decreased risk of BE in a veteran population. Such an inverse association may be partially mediated by lutein, fiber, and folate. The novel findings on the association between intake of lutein, total folate, or isoflavones and risk of BE need further confirmation.

Risk factors for neoplastic progression in Barrett’s esophagus

Barrett’s esophagus (BE) confers a significant increased risk for development of esophageal adenocarcinoma (EAC), with the pathogenesis appearing to progress through a “metaplasia-dysplasia-carcinoma” (MDC) sequence. Many of the genetic insults driving this MDC sequence have recently been characterized, providing targets for candidate biomarkers with potential clinical utility to stratify risk in individual patients. Many clinical risk factors have been investigated, and associations with a variety of genetic, specific gastrointestinal and other modifiable factors have been proposed in the literature. This review summarizes the current understanding of the mechanisms involved in neoplastic progression of BE to EAC and critically appraises the relative roles and contributions of these putative risk factors from the published evidence currently available.

Chemoprevention in Barrett's oesophagus

Barrett's oesophagus normally affects the distal oesophagus when metaplastic columnar lined epithelium replaces stratified squamous epithelium which predisposes to cancer development. This develops as a consequence of chronic gastroesophageal reflux (GORD). Those with Barrett's have a 40 fold increased risk of oesophageal adenocarcinoma [1]. There are is still a lack of understanding of the natural history of the cell of origin. This does hamper research into this area. We accept that there is a limitation in testing of the pathogenesis of Barrett's oesophagus due to a lack of a universally accepted animal model. The major questions surrounding Barrett's oesophagus include validity of surveillance strategies, the optimal treatment and more importantly an agent that can prevent progression to cancer without unacceptable side effects. The main chemopreventative agents that show promise are aspirin and proton pump inhibitors (PPIs). There are other agents such as green tea, berries and antioxidants and diet that have been suggested; we discuss the evidence available for these strategies. We hope for continued improvement in the clinical trial infrastructure to facilitate testing of new pharmacological and endoscopic interventions for Barrett's oesophagus.

Chemoprevention of esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) is rising rapidly in Western countries, and effective chemoprevention for this malignancy is lacking. Endoscopic surveillance of patients with Barrett's esophagus is currently employed to diagnose EAC at earlier stages, but this strategy has several limitations. Non-steroidal anti-inflammatory drugs and proton pump inhibitors are the most promising agents for prevention of EAC, and a randomized controlled trial of aspirin and esomeprazole is ongoing. Other agents under investigation include green tea, berries, and antioxidants. Cost-effectiveness analyses have shown that chemopreventive agents need to be highly effective at preventing EAC in order to have benefit beyond endoscopic surveillance.

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.

Cellular proliferation, apoptosis and angiogenesis: molecular targets for nutritional preemption of cancer

Malignant cells are characterized by abnormal signaling pathways involving proliferation, apoptosis, and angiogenesis. These cancer centric pathways are known to be modified by several bioactive dietary components, although admittedly there are inconsistencies in the response. The response is dependent on the amount and duration of exposure to the dietary component and the cell type. While caution should be exercised when extrapolating in vitro data to in vivo conditions, such studies do provide valuable insights into plausible mechanisms. Significant gene-nutrient and nutrient-nutrient interactions may contribute to the uncertainty of the response to foods and/or their components. One of the challenges is the identification of which process(es), either singly or in combination, is/are most important in leading to a dietary-mediated phenotypic change. The dearth of controlled intervention studies that have investigated molecular targets for nutritional preemption in humans make firm dietary recommendations difficult. Until more definite information surfaces, a balanced but varied diet is most prudent.

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.

Systematic review of long-term lifestyle interventions to prevent weight gain and morbidity in adults

The aim of this article is to determine the effectiveness of long-term lifestyle interventions for the prevention of weight gain and morbidity in adults. Prevention of weight gain is important in adults who are of normal weight, overweight and obese. A systematic review of controlled trials of lifestyle interventions in adults with a body mass index of less than 35 kg m(-2) with at least 2 years of follow-up was carried out. Eleven of 39 comparisons produced significant improvement in weight between groups at 2 years or longer with mean difference weight change ranging from -0.5 to -11.5 kg. Effective interventions included a 600 kcal/day deficit diet deficit/low-fat diet (with and without meal replacements), low-calorie diet, Weight Watchers diet, low-fat non-reducing diet, diet with behaviour therapy, diet with exercise, diet with exercise and behaviour therapy. Adding meal replacements to a low-fat diet (with and without exercise and behaviour therapy) produced significant improvement in weight. Head-to-head interventions failed to show significant effect on weight with the exception of a Mediterranean diet with behaviour therapy compared with low-fat diet. Diet with exercise and/or behaviour therapy demonstrated significant reduction in hypertension and improvement in risk of metabolic syndrome and diabetes compared with no treatment control. Lifestyle interventions demonstrated significant improvement in weight, reduction in hypertension and reduction in risk of type 2 diabetes and the metabolic syndrome.

Role of obesity in Barrett's esophagus and cancer

The incidence of esophageal adenocarcinoma (EAC) has increased dramatically in the western world, and there also appears to have been an increase in the incidence of Barrett's esophagus and gastroesophageal reflux disease in recent years. The contemporaneous increase in obesity has focused interest on whether obesity is a risk factor for EAC and its precursors. This article reviews current evidence for the role that overweight/obesity and body fat distribution have in development of the esophagitis metaplasia-dysplasia-adenocarcinoma sequence. Particular attention is paid to the stage at which adiposity may act to influence the risk of EAC, because this determines the importance of weight control and weight loss at each stage in the disease spectrum for the prevention of EAC.

A dietary intervention to elicit rapid and complex dietary changes for studies investigating the effects of diet on tissues collected during invasive surgical procedures

Nutrition intervention trials in patients undergoing surgical treatment for cancer offer a unique opportunity to study the mechanisms and pathways that underlie diet and cancer associations in target tissues. However, due to the short time period between diagnosis and treatment, traditional dietary intervention methods are not feasible. This report describes a novel dietary intervention program designed to elicit rapid and complex dietary change during a condensed study period. The intervention, based on Consumer Information Processing, used standardized menus and exchange lists to guide food choices, and was delivered using a single, in-person session followed by telephone-based counseling. This intervention program was used in a small pilot study evaluating the short-term effects of dietary change in men with newly diagnosed prostate cancer. Eight men were randomly assigned to either a low-fat/low-glycemic load or standard American diet during the 4 weeks preceding prostate surgery. Participants completed 24-hour dietary recalls each week, and were weighed at baseline and at surgery. Compared to men in the standard American arm (n=4), men in the low-fat/low-glycemic arm (n=4) reported consuming less total fat (51.0+/-36.0 vs 93.5+/-8.4 g/day, P=0.06), and had a lower glycemic load (134.8+/-6.0 vs 266.3+/-36.8 units/day, P<0.001). Men in the low-fat/low-glycemic arm lost a mean of 5.3+/-1.7 kg and men in the standard American arm gained 0.8+/-4.5 kg (P=0.04). Results of this small pilot study suggest that a relatively simple and minimally burdensome dietary intervention can elicit rapid and complex dietary changes that are maintained over a 4-week study period. Further studies in larger and more diverse populations are needed to fully understand the potential of this novel intervention approach.

Evaluation of risk factors and prevention strategies of esophageal cancer

Esophageal cancer is one of the most common fatal cancers worldwide. There are two major types of esophageal cancer, squamous cell carcinoma and adenocarcinoma. Because of the poor survival rate of esophageal cancer, successful assessment of risk factors and prevention strategies become crucial in prevention and treatment of this cancer. This article reviews the most updated research discoveries and reveals that tobacco, alcohol consumption and bad eating habits are considered as the major risk factors for esophageal cancer. Carcinogens-contaminated food, unbalanced diet, genetic susceptibility and some chronic gastrointestinal disease are also factors contributed to esophageal cancer development. To prevent this disease, there are two major strategies, primary and secondary preventions.

Dietary antioxidants, fruits, and vegetables and the risk of Barrett's esophagus

OBJECTIVE

The present study evaluated the associations among antioxidants, fruit and vegetable intake, and the risk of Barrett's esophagus (BE), a potential precursor to esophageal adenocarcinoma.

METHODS

We conducted a case-control study within the Kaiser Permanente Northern California population. Incident BE cases (N = 296) were matched to persons with gastroesophageal reflux disease (GERD) (GERD controls N = 308) and to population controls (N = 309). Nutrient intake was measured using a validated 110-item food frequency questionnaire. The antioxidant results were stratified by dietary versus total intake of antioxidants.

RESULTS

Comparing cases to population controls, dietary intake of vitamin C and beta-carotene were inversely associated with the risk of BE (4th vs 1st quartile, adjusted odds ratio [OR] 0.48, 95% confidence interval [CI] 0.26-0.90; OR 0.56, 95% CI 0.32-0.99, respectively), and the inverse association was strongest for vitamin E (OR 0.25, 95% CI 0.11-0.59). The inverse trends for antioxidant index (total and dietary) and fruit and vegetable intake were statistically significant, while most total intakes were not associated with reduced risk. The use of antioxidant supplements did not influence the risk of BE, and antioxidants and fruits and vegetables were inversely associated with a GERD diagnosis.

CONCLUSION

Dietary antioxidants, fruits, and vegetables are inversely associated with the risk of BE, while no association was observed for supplement intake. Our results suggest that fruits and vegetables themselves or associated undetected confounders may influence early events in the carcinogenesis of esophageal adenocarcinoma.