Dietary flavonoid intake and Barrett's esophagus in western Washington State

Lignan exposure: a worldwide perspective

Dietary lignans are phytoestrogens that are mostly found in plant-based foods, especially whole grains, seeds, nuts, legumes and vegetables. An accurate assessment of lignan exposure is crucial to evaluate their potential health benefits and to establish future recommendations and dietary guidelines. This narrative review aimed to (i) summarize the pros and the cons of the current main assessment methods for lignan exposure─i.e., dietary questionnaires, food composition tables and biomarkers, (ii) describe the individual lignans more consumed from a worldwide perspective, as well as their main food sources, (iii) determine the lignans concentrations in both urine and blood, and explore their heterogeneity among countries, and finally (iv) discuss the main determinants of lignan exposure.

Dietary and Lifestyle Factors Related to Gastroesophageal Reflux Disease: A Systematic Review

We performed this review to clarify which dietary and lifestyle factors are related to gastroesophageal reflux disease. Through a systematic search of the PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and Chinese BioMedical Literature (CBM) databases, we identified articles with clear definitions of GERD, including nonerosive gastroesophageal reflux disease (NERD), reflux esophagitis (RE) and Barrett’s esophagus (BE), that included dietary and lifestyle factors as independent factors affecting the onset of GERD (expressed as odds ratios (ORs) or relative risks (RRs) and 95% confidence intervals (CIs)). Due to heterogeneity among the studies, we used descriptive statistical analyses to analyze and synthesize each outcome based on the disease type. In total, 72 articles were included, conducted in ten Western countries (26 articles in total) and nine Eastern countries (46 articles in total). We categorized dietary factors into 20 items and lifestyle factors into 11 items. GERD is related to many irregular dietary and lifestyle habits (such as a habit of midnight snacking: OR=5.08, 95% CI 4.03–6.4; skipping breakfast: OR=2.7, 95% CI 2.17–3.35; eating quickly: OR=4.06, 95% CI 3.11–5.29; eating very hot foods: OR=1.81, 95% CI 1.37–2.4; and eating beyond fullness: OR=2.85, 95% CI 2.18–3.73). Vegetarian diets (consumption of nonvegetarian food (no/yes); OR=0.34, 95% CI 0.211–0.545) and no intake of meat (OR=0.841, 95% CI 0.715–0.990) were negatively related to GERD, while meat (daily meat, fish, and egg intake: OR=1.088, 95% CI 1.042-1.135) and fat (high–fat diet: OR=7.568, 95% CI 4.557–8.908) consumption were positively related to GERD. An interval of less than three hours between dinner and bedtime (OR=7.45, 95% CI 3.38–16.4) was positively related to GERD, and proper physical exercise (physical exercise >30 minutes (>3 times/week): OR=0.7, 95% CI 0.6–0.9) was negatively correlated with GERD. Smoking (OR=1.19, 95% CI 1.12–1.264), alcohol consumption (OR=1.278, 95% CI 1.207–1.353) and mental state (poor mental state: OR=1.278, 95% CI 1.207–1.353) were positively correlated with GERD. RE (vitamin C: OR=0.46, 95% CI=0.24–0.90) and BE (vitamin C: OR=0.44,95% CI 0.2-0.98; vitamin E: OR=0.46, 95% CI 0.26–0.83) were generally negatively correlated with antioxidant intake. In conclusion, many dietary and lifestyle factors affect the onset of GERD, and these factors differ among regions and disease types. These findings need to be further confirmed in subsequent studies.

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.

Intake of Individual Flavonoids and Risk of Carcinogenesis: Overview of Epidemiological Evidence

Several epidemiological findings have demonstrated that specific flavonoids can be responsible for reduction of the risk of certain cancer types. However, these results are still rather limited, inconclusive and controversial. Therefore, in this comprehensive review article the findings reported to date about the associations between dietary intake of individual flavonoid compounds and cancer incidence are compiled and analyzed. Also, the possible reasons for inconsistencies are brought forth and discussed. As diet is a potentially modifiable factor in our behavioral choices, further large-scale prospective studies with longer follow-up times, different populations, various doses and exposure timing as well as diverse well-controlled confounders are highly needed to confirm or disprove the current epidemiological knowledge about the role of flavonoids on cancer risk. Regarding the promising data to date, more research on bioavailability, metabolism and biological action mechanisms of these plant secondary metabolites is also encouraged.

Flavonoids, Flavonoid Subclasses, and Esophageal Cancer Risk: A Meta-Analysis of Epidemiologic Studies

Flavonoids have been suggested to play a chemopreventive role in carcinogenesis. However, the epidemiologic studies assessing dietary intake of flavonoids and esophageal cancer risk have yielded inconsistent results. This study was designed to examine the association between flavonoids, each flavonoid subclass, and the risk of esophageal cancer with a meta-analysis approach. We searched for all relevant studies with a prospective cohort or case-control study design published from January 1990 to April 2016, using PUBMED, EMBASE, and Web of Science. Pooled odds ratios (ORs) were calculated using fixed or random-effect models. In total, seven articles including 2629 cases and 481,193 non-cases were selected for the meta-analysis. Comparing the highest-intake patients with the lowest-intake patients for total flavonoids and for each flavonoid subclass, we found that anthocyanidins (OR = 0.60, 95% CI: 0.49-0.74), flavanones (OR = 0.65, 95% CI: 0.49-0.86), and flavones (OR = 0.78, 95% CI 0.64-0.95) were inversely associated with the risk of esophageal cancer. However, total flavonoids showed marginal association with esophageal cancer risk (OR = 0.78, 95% CI: 0.59-1.04). In conclusion, our study suggested that dietary intake of total flavonoids, anthocyanidins, flavanones, and flavones might reduce the risk of esophageal cancer.