Fruits, vegetables and lung cancer: a pooled analysis of cohort studies

Dietary factors and the risk of lung cancer by epidermal growth factor receptor mutation status and histological subtypes

Background

Previous studies have reported differential associations of certain dietary factors such as soy consumption by epidermal growth factor receptor mutant (EGFR +) subtype of non-small cell lung cancer (NSCLC). However, whether the other dietary factors including meat, fruits, and vegetables have differential risks on different histological and molecular subtypes of lung cancer remains unclear. Therefore, we conducted a case-control study to evaluate these associations.

Methods

A total of 3,170 cases and 4,238 controls from three different studies (Genes and Environment in Lung Cancer Study, Lung Cancer Consortium Singapore Study, and Multi-ethnic Cohort Study) were included. Information on demographics, lifestyle, and dietary consumption was obtained using questionnaires. Diet was assessed by using the number of standard servings of each item consumed per week. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between meat, vegetables, and fruits consumption with lung cancer risk after adjusting for potential confounders.

Results

We identified a significant inverse association between higher consumption of fruits and the risk of lung cancer (2nd tertile: OR = 0.54, 95%CI = 0.46-0.65; 3rd tertile: OR = 0.77, 95%CI = 0.65-0.91), compared with the lower (1st tertile) consumption of fruits. Higher vegetable consumption was significantly associated with a lower risk of EGFR + lung cancer (OR = 0.69, 95% CI = 0.54-0.88), however, this association was not significant among EGFR wild-type (-) lung cancer. Conversely, higher consumption of total meat (OR = 2.10, 95%CI = 1.58-2.79) was significantly associated with higher lung cancer risk, as compared with the lower consumption group.

Conclusions

Differential associations between vegetable consumption with EGFR mutation status in NSCLC were found. Further prospective studies are warranted to assess this association and elucidate the biological mechanisms.

The Potential Role of Nutrition in Lung Cancer Establishment and Progression

Lung cancer is a devastating disease with a high incidence and low survival rates, so recent studies have focused on analyzing the risk factors that might prevent this disease from developing or have protective/therapeutic effects. Nutrition is an important key factor in the prevention and treatment of lung cancer. Various factors appear to be involved in the development of the latter, such as cigarette smoking or certain external environmental factors. The increase in oxidative stress is therefore an integral part of the carcinogenesis process. The biological role of bioactive factors derived from adipose tissue, mainly adipokines, is implicated in various cancers, and an increasing body of evidence has shown that certain adipocytokines contribute to the development, progression and prognosis of lung cancer. Not all adipokines stimulate tumor growth; in fact, adiponectin inhibits carcinogenesis by regulating both cell growth and the levels of inflammatory cytokines. Adiponectin expression is deregulated in several cancer types. Many nutritional factors have been shown to increase adiponectin levels and therefore could be used as a new therapeutic strategy for combating lung cancer. In addition, foods with antioxidant and anti-inflammatory properties play a key role in the prevention of many human diseases, including lung cancer. The purpose of this review is to analyze the role of diet in lung cancer in order to recommend dietary habit and lifestyle changes to prevent or treat this pathology.

Sulforaphane as a potential remedy against cancer: Comprehensive mechanistic review

Sulforaphane belongs to the active class of isothiocyanates capable of delivering various biological benefits for health promotion and disease prevention. This compound is considered vital to curtail numerous metabolic disorders. Various studies have proven its beneficial effects against cancer prevention and its possible utilization as a therapeutic agent in cancer treatment. Understanding the mechanistic pathways and possible interactions at cellular and subcellular levels is key to design and develop cancer therapeutics for humans. In this respect, a number of mechanisms such as modulation of carcinogen metabolism & phase II enzymatic activities, cell cycle arrest, activation of Nrf2, cytotoxic, proapoptotic and apoptotic pathways have been reported to be involved in cancer prevention. This article provides sufficient information by critical analysis to understand the mechanisms involved in cancer prevention attributed to sulforaphane. Furthermore, various clinical studies have also been included for design and development of novel therapies for cancer prevention and cure. PRACTICAL APPLICATIONS: Diet and dietary components are potential tools to address various lifestyle-related disorders. Due to plenty of environmental and cellular toxicants, the chances of cancer prevalence are quite large which are worsen by adopting unhealthy lifestyles. Cancer can be treated with various therapies but those are acquiring side effects causing the patients to suffer the treatment regime. Nutraceuticals and functional foods provide safer options to prevent or delay the onset of cancer. In this regard, sulforaphane is a pivotal compound to be targeted as a potential agent for cancer treatment both in preventive and therapeutic regimes. This article provides sufficient evidence via discussing the underlying mechanisms of positive effects of sulforaphane to further the research for developing anticancer drugs that will help assuage this lethal morbidity.

Diet and Risk of Myeloproliferative Neoplasms in Older Individuals from the NIH-AARP Cohort

BACKGROUND

The etiology of myeloproliferative neoplasms (MPN) is obscure, and no previous studies have evaluated the role of diet.

METHODS

In the NIH-AARP Diet and Health Study, a prospective cohort of 463,049 participants ages 50 to 71 years at baseline (1995-1996), we identified 490 MPN cases after a median follow-up of 15.5 years, including 190 with polycythemia vera (PV) and 146 with essential thrombocythemia (ET). We examined possible associations between various dietary factors and the risk of MPN as a group, as well as PV and ET, using multivariable Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) and adjust for potential confounding variables.

RESULTS

An increased risk was observed between fruit consumption and the risk of MPN overall (third tertile vs. first tertile, HR = 1.32; 95% CI, 1.04-1.67; P _trend = 0.02) and PV (third tertile vs. first tertile, HR = 2.00; 95% CI, 1.35-2.95; P _trend < 0.01). Increased risk of PV was also observed among those with high intake of sugar (HR = 1.77; 95% CI, 1.12-2.79), sugar from natural sources (HR = 1.77; 95% CI, 1.16-2.71), sugar from natural beverage sources (HR = 1.57; 95% CI, 1.08-2.29), and fructose (HR = 1.84; 95% CI, 1.21-2.79).

CONCLUSIONS

The intake of fat and protein did not appear to influence PV risk-neither did meat or vegetable consumption. None of the dietary factors studied was associated with the risk of ET. The role of sugar intake in the etiology of PV in older individuals warrants further investigation.

IMPACT

Our results indicate that high sugar intake is associated with an increased risk of polycythemia vera.

Plant Foods, Antioxidant Biomarkers, and the Risk of Cardiovascular Disease, Cancer, and Mortality: A Review of the Evidence

Although a high intake of plant foods such as fruits, vegetables, whole grains, nuts, and legumes has been recommended for chronic disease prevention, it has been unclear what is the optimal amount of intake of these foods and whether specific subtypes are particularly beneficial. The evidence from several recently published meta-analyses on plant foods and antioxidants and various health outcomes is reviewed as well as more recently published studies. In meta-analyses of prospective studies, inverse associations were observed between intake of fruits, vegetables, whole grains, and nuts and the risk of coronary artery disease, stroke, cardiovascular disease overall, total cancer, and all-cause mortality. The strongest reductions in risk were observed at an intake of 800 g/d for fruits and vegetables, 225 g/d for whole grains, and 15-20 g/d for nuts, respectively. Whole-grain and nut consumption was also inversely associated with mortality from respiratory disease, infections, and diabetes. Stronger and more linear inverse associations were observed between blood concentrations of antioxidants (vitamin C, carotenoids, vitamin E) and cardiovascular disease, cancer, and all-cause mortality than for dietary intake. Most studies that have since been published have been consistent with these results; however, further studies are needed on subtypes of plant foods and less common causes of death. These results strongly support dietary recommendations to increase intake of plant foods, and suggest optimal intakes for chronic disease prevention may be ∼800 g/d for intakes of fruits and vegetables, 225 g/d for whole grains, and 15-20 g/d for nuts. Diets high in plant foods could potentially prevent several million premature deaths each year if adopted globally.

Isolation of strawberry anthocyanin-rich fractions and their mechanisms of action against murine breast cancer cell lines

The aim of this study was the evaluation of the effects of strawberry anthocyanin extract treatment on two in vitro models of murine breast cancer cell lines, in an attempt to detect a specific pathway (AMP-activated protein kinase or AMPK) through which strawberries exert their anticancer activity. The anticancer activity of purified anthocyanin extracts from an Alba cultivar on two murine cancer cell lines, N202/1A (with high levels of the HER2/neu oncogene) and N202/1E (with low levels of the HER2/neu oncogene), was evaluated after 48 and 72 h of treatment. The cell viability and apoptosis, intracellular ROS rates, and cell oxidative damage were assessed. Western blot assays were performed to analyze the expression of several proteins related to apoptosis, autophagy, metastasis, the oxidative status, mitochondrial functionality, and the AMPK pathway. This study demonstrated that the anthocyanin extract of Alba strawberry shows an antiproliferative effect on cancer cells, through the induction of apoptosis and oxidative stress, by stimulating different molecular pathways. This study is one of the first studies that have tried to deepen the understanding of a candidate pathway for the explanation of the effects of strawberry on cancer cells. A relationship between the AMPK pathway and the anticancer effects of strawberries was demonstrated.

Molecular Insights into Potential Contributions of Natural Polyphenols to Lung Cancer Treatment

Naturally occurring polyphenols are believed to have beneficial effects in the prevention and treatment of a myriad of disorders due to their anti-inflammatory, antioxidant, antineoplastic, cytotoxic, and immunomodulatory activities documented in a large body of literature. In the era of molecular medicine and targeted therapy, there is a growing interest in characterizing the molecular mechanisms by which polyphenol compounds interact with multiple protein targets and signaling pathways that regulate key cellular processes under both normal and pathological conditions. Numerous studies suggest that natural polyphenols have chemopreventive and/or chemotherapeutic properties against different types of cancer by acting through different molecular mechanisms. The present review summarizes recent preclinical studies on the applications of bioactive polyphenols in lung cancer therapy, with an emphasis on the molecular mechanisms that underlie the therapeutic effects of major polyphenols on lung cancer. We also discuss the potential of the polyphenol-based combination therapy as an attractive therapeutic strategy against lung cancer.

The Associations of Fruit and Vegetable Intake with Lung Cancer Risk in Participants with Different Smoking Status: A Meta-Analysis of Prospective Cohort Studies

The results of epidemiological studies on the relationship between fruit and vegetable intake and lung cancer risk were inconsistent among participants with different smoking status. The purpose of this study was to investigate these relationships in participants with different smoking status with prospective cohort studies. A systematic literature retrieval was conducted using PubMed and Scopus databases up to June 2019. The summary relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were calculated by random-effects model. The nonlinear dose-response analysis was carried out with restricted cubic spline regression model. Publication bias was estimated using Begg’s test. Nine independent prospective studies were included for data synthesis. Dietary consumption of fruit was negatively correlated with lung cancer risk among current smokers and former smokers, and the summery RRs were 0.86 (95% CI: 0.78, 0.94) and 0.91 (95% CI: 0.84, 0.99), respectively. Consumption of vegetable was significantly associated with reduced risk of lung cancer for current smokers (summary RR = 87%; 95% CI: 0.78, 0.94), but not for former smokers and never for smokers. Dose-response analysis suggested that risk of lung cancer was reduced by 5% (95% CI: 0.93, 0.97) in current smokers, and reduced by 4% (95% CI: 0.93, 0.98) in former smokers with an increase of 100 grams of fruit intake per day, respectively. Besides, dose-response analysis indicated a 3% reduction in lung cancer risk in current smokers for 100 gram per day increase of vegetable intake (95% CI: 0.96, 1.00). The findings of this study provide strong evidence that higher fruit consumption is negatively associated with the risk of lung cancer among current smokers and former smokers, while vegetable intake is significantly correlated with reducing the risk of lung cancer in current smokers. These findings might have considerable public health significance for the prevention of lung cancer through dietary interventions.

Notch signaling in breast cancer: From pathway analysis to therapy

The Notch signaling pathway, which is highly conserved from sea urchins to humans, plays an important role in cell-differentiation, survival, proliferation, stem-cell renewal, and determining cell fate during development and morphogenesis. It is well established that signaling pathways are dysregulated in a wide-range of diseases, including human malignancies. Studies suggest that the dysregulation of the Notch pathway contributes to carcinogenesis, cancer stem cell renewal, angiogenesis, and chemo-resistance. Elevated levels of Notch receptors and ligands have been associated with cancer-progression and poor survival. Furthermore, the Notch signaling pathway regulates the transcriptional activity of key target genes through crosstalk with several other signaling pathways. Indeed, increasing evidence suggests that the Notch signaling pathway may serve as a therapeutic target for the treatment of several cancers, including breast cancer. Researchers have demonstrated the anti-tumor properties of Notch inhibitors in various cancer types. Currently, Notch inhibitors are being evaluated for anticancer efficacy in a number of clinical-trials. However, because there are multiple Notch receptors that can exhibit either oncogenic or tumor-suppressing roles in various cells, it is important that the Notch inhibitors are specific to particular receptors that are tumorigenic in nature. This review critically evaluates existing Notch inhibitory drugs and strategies and summarizes the previous discoveries, current understandings, and recent developments in support of Notch receptors as therapeutic targets in breast cancer.

African-American Women's Tobacco and Marijuana Use: The Effects of Social Context and Substance Use Perceptions

BACKGROUND

Despite the status of tobacco and marijuana as two of the most commonly used substances in the U.S., both have detrimental health and social consequences for disfranchized African-Americans. Substance use may be shaped by social contextual influences from families and peers in African-American communities, and little research has examined perceptions of wrongfulness, harms, and dangers associated with daily tobacco and marijuana use among African-American women.

OBJECTIVES

This study explores the effects of African-American women's social context and substance use perceptions (wrongfulness/harmfulness/dangerousness) on daily tobacco and marijuana use.

METHODS

Survey data was collected in-person from 521 African-American women. Multivariate logistic models identified the significant correlates of women's daily use of tobacco and marijuana in the past six months.

RESULTS

52.59% of participants reported daily tobacco use and 10.56% used marijuana daily. Multivariate models indicated that women were more likely to be daily tobacco users if they had a family member with a substance use problem or perceived tobacco use to be wrong, harmful, or more dangerous than marijuana. In the models with marijuana as the dependent variable, women who lived with a person who used drugs were more likely to use marijuana daily. Perceiving marijuana use as wrong or harmful to one's health was protective against daily marijuana use.

CONCLUSIONS

Findings stress the need for prevention and intervention efforts for African-American women that highlight social context influences and promote greater awareness of the health risks associated with daily tobacco and marijuana use.

Factors affecting the development of airflow limitation among South Korean smokers

INTRODUCTION

Considering that only some and not all smokers develop chronic obstructive pulmonary disease (COPD), there may be other factors responsible for the development of COPD among smokers. Previous researchers have reported that ethnicity could be one of factors associated with the development of COPD. This study aimed to examine the factors associated with the development of airflow limitation, suggestive of having COPD, among Korean smokers using data from the Korea National Health and Nutrition Examination Survey conducted over the past 3 years.

METHODS

A total of 2569 current and former smokers ≥40 years of age were included. Most studies exploring risk factors for COPD have compared smokers and non-smokers with smoking as only one of the independent variables. In this study, we took a different approach, studying only smokers and comparing those with or without airflow limitation.

RESULTS

The prevalence of airflow limitation among the study participants was 19.2% and 22.1% in current and former smokers, respectively. There was no significant correlation between the severity of airflow limitation and total lifetime smoking amount. Among the many variables examined, only age, male gender and total lifetime smoking amount (pack-years) were significant factors associated with the development of cigarette smoke-induced airflow limitation.

CONSLUSIONS

Older Korean men who are heavy smokers may be at a higher risk of developing COPD. Our findings support the importance of smoking cessation as the best way to prevent the development of COPD.

Effects of smoking on disease risk among South Korean adults

INTRODUCTION

Tobacco smoking is currently considered to be the main preventable cause of death and disability worldwide. We examined the magnitude of cigarette smoking effects on major smoking-related diseases, such as chronic obstructive pulmonary disease (COPD), hypertension (HTN) and cardiovascular disease (CVD), among South Korean adults using nationwide and representative survey data.

METHODS

We used data from the Korea National Health and Nutrition Examination Survey, which was conducted over a 9-year period from 2007 to 2015 by the Korea Centers for Disease Control and Prevention. Multiple logistic regression analyses were performed to assess the associations between smoking status and all outcomes of interest. A total of 24072 participants ≥40 years of age were sampled in the current study.

RESULTS

The study results were as follows: 1) Current and former smoking is associated with lower socioeconomic status; 2) The prevalence of major smoking-related diseases was significantly higher in former and current smokers compared to non-smokers; 3) The odd ratios of developing COPD were 3.49 [95% confidence interval (CI): 2.44-5.00], 2.41 (95% CI: 1.68-3.45) and 3.45 (95% CI: 2.20-5.40) among male current smokers, male ex-smokers and female current smokers, respectively. The odd ratio of developing CVD was 2.01 (95% CI: 1.05-3.86) in male ex-smokers. Otherwise, no significant associations between smoking and other diseases were observed after controlling the sociodemographic and clinical factors; and 4) The risk for COPD tends to be related to the smoking amount and weaning after quitting smoking.

CONCLUSIONS

Our study showed that COPD had the strongest association with current and former smoking in both male and female smokers after controlling for all potential confounding factors among major smoking-related diseases.

Dietary Inflammatory Index and Site-Specific Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis

Existing evidence suggests a link between the inflammatory potential of diet and risk of cancer. This study aimed to test the linear and potential nonlinear dose-response associations of the Dietary Inflammatory Index (DII), as being representative of inflammatory features of the diet, and site-specific cancer risk. A systematic search was conducted with the use of PubMed and Scopus from 2014 to November 2017. Prospective cohort or case-control studies reporting the risk estimates of any cancer type for ≥3 categories of the DII were selected. Studies that reported the association between continuous DII score and cancer risk were also included. Pooled RRs were calculated by using a random-effects model. Eleven prospective cohort studies (total n = 1,187,474) with 28,614 incident cases and 29 case-control studies with 19,718 cases and 33,229 controls were identified. The pooled RRs for a 1-unit increment in the DII were as follows: colorectal cancer, 1.06 (95% CI: 1.04, 1.08; I2 = 72.5%; n = 9); breast cancer, 1.03 (95% CI: 1.00, 1.07; I2 = 84.0%; n = 7); prostate cancer, 1.06 (95% CI: 0.97, 1.15; I2 = 56.2%; n = 6); pancreatic cancer, 1.16 (95% CI: 1.05, 1.28; I2 = 61.6%; n = 2); ovarian cancer, 1.08 (95% CI: 1.03, 1.13; I2 = 0%; n = 2); esophageal squamous cell carcinoma, 1.24 (95% CI: 1.10, 1.38; I2 = 64.3%; n = 2); renal cell carcinoma, 1.08 (95% CI: 1.02, 1.13; I2 = 0%; n = 2); and esophageal adenocarcinoma, 1.26 (95% CI: 1.13, 1.39; I2 = 0%; n = 2). A nonlinear dose-response meta-analysis showed that, after a somewhat unchanged risk within initial scores of the DII, the risk of colorectal cancer increased linearly with increasing DII score. In the analyses of breast and prostate cancers, the risk increased with a very slight trend with increasing DII score. In conclusion, the results showed that dietary habits with high inflammatory features might increase the risk of site-specific cancers.

The Role of Cruciferous Vegetables and Isothiocyanates for Lung Cancer Prevention: Current Status, Challenges, and Future Research Directions

Lung cancer remains a leading cause of cancer-related deaths in the United States. Although smoking and air pollution exposure are primary risk factors of lung cancer, diet has also been reported to contribute to lung cancer risk. Cruciferous vegetables contain many bioactive compounds that alter the detoxification process of air-borne carcinogenic compounds and, thereby, may decrease lung cancer risk. In the meta-analysis of 31 observational studies, cruciferous vegetable intake is inversely associated with lung cancer risk (summary odds ratio/relative risk = 0.81 and 95% confidence interval = 0.74-0.89 for comparing the highest with lowest intake categories). More observational studies need to measure urinary isothiocyanate (ITC) concentrations and investigate their association with lung cancer risk in populations with relatively high intake of cruciferous vegetables. Current evidence is limited to two phase 2 clinical trials with incomplete reporting. Hence, more short-term clinical phase 2 trials need to examine effects of various amounts and types of cruciferous vegetables on biomarkers of risk and efficacy before a large phase 3 trial can be conducted to assess effects upon lung cancer risk. This would help further elucidate whether the inverse association observed with self-reported cruciferous vegetable intake is indeed due to ITC content or other bioactive compounds.

A pooled analysis of dietary sugar/carbohydrate intake and esophageal and gastric cardia adenocarcinoma incidence and survival in the USA

Background

During the past 40 years, esophageal/gastric cardia adenocarcinoma (EA/GCA) incidence increased in Westernized countries, but survival remained low. A parallel increase in sugar intake, which may facilitate carcinogenesis by promoting hyperglycaemia, led us to examine sugar/carbohydrate intake in association with EA/GCA incidence and survival.

Methods

We pooled 500 EA cases, 529 GCA cases and 2027 controls from two US population-based case-control studies with cases followed for vital status. Dietary intake, assessed by study-specific food frequency questionnaires, was harmonized and pooled to estimate 12 measures of sugar/carbohydrate intake. Multivariable-adjusted odds ratios (ORs) and hazard ratios [95% confidence intervals (CIs)] were calculated using multinomial logistic regression and Cox proportional hazards regression, respectively.

Results

EA incidence was increased by 51-58% in association with sucrose (ORQ5vs.Q1 = 1.51, 95% CI = 1.01-2.27), sweetened desserts/beverages (ORQ5vs.Q1 = 1.55, 95% CI = 1.06-2.27) and the dietary glycaemic index (ORQ5vs.Q1 = 1.58, 95% CI = 1.13-2.21). Body mass index (BMI) and gastro-esophageal reflux disease (GERD) modified these associations (Pmultiplicative-interaction ≤ 0.05). For associations with sucrose and sweetened desserts/beverages, respectively, the OR was elevated for BMI < 25 (ORQ4-5vs.Q1-3 = 1.79, 95% CI = 1.26-2.56 and ORQ4-5vs.Q1-3 = 1.45, 95% CI = 1.03-2.06), but not BMI ≥ 25 (ORQ4-5vs.Q1-3 = 1.05, 95% CI = 0.76-1.44 and ORQ4-5vs.Q1-3 = 0.85, 95% CI = 0.62-1.16). The EA-glycaemic index association was elevated for BMI ≥ 25 (ORQ4-5vs.Q1-3 = 1.38, 95% CI = 1.03-1.85), but not BMI < 25 (ORQ4-5vs.Q1-3 = 0.88, 95% CI = 0.62-1.24). The sucrose-EA association OR for GERD < weekly was 1.58 (95% CI = 1.16-2.14), but for GERD ≥ weekly was 1.01 (95% CI = 0.70-1.47). Sugar/carbohydrate measures were not associated with GCA incidence or EA/GCA survival.

Conclusions

If confirmed, limiting intake of sucrose (e.g. table sugar), sweetened desserts/beverages, and foods that contribute to a high glycaemic index, may be plausible EA risk reduction strategies.

Dietary sugar/starches intake and Barrett's esophagus: a pooled analysis

Barrett's esophagus (BE) is the key precursor lesion of esophageal adenocarcinoma, a lethal cancer that has increased rapidly in westernized countries over the past four decades. Dietary sugar intake has also been increasing over time, and may be associated with these tumors by promoting hyperinsulinemia. The study goal was to examine multiple measures of sugar/starches intake in association with BE. This pooled analysis included 472 BE cases and 492 controls from two similarly conducted case-control studies in the United States. Dietary intake data, collected by study-specific food frequency questionnaires, were harmonized across studies by linking with the University of Minnesota Nutrient Database, and pooled based on study-specific quartiles. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age, sex, race, total energy intake, study indicator, body mass index, frequency of gastro-esophageal reflux, and fruit/vegetable intake. In both studies, intake of sucrose (cases vs. controls, g/day: 36.07 vs. 33.51; 36.80 vs. 35.06, respectively) and added sugar (46.15 vs. 41.01; 44.18 vs. 40.68, respectively) were higher in cases than controls. BE risk was increased 79% and 71%, respectively, for associations comparing the fourth to the first quartile of intake of sucrose (OR_Q4vs.Q1 = 1.79, 95% CI = 1.07-3.02, P _trend = 0.01) and added sugar (OR_Q4vs.Q1 = 1.71, 95% CI = 1.05-2.80, P _trend = 0.15). Intake of sweetened desserts/beverages was associated with 71% increase in BE risk (OR_Q4vs.Q1 = 1.71, 95% CI = 1.07-2.73, P _trend = 0.04). Limiting dietary intake of foods and beverages that are high in added sugar, especially refined table sugar, may reduce the risk of developing BE.

WITHDRAWN: The anti-cancer properties in parallel with toxic effects of indole-3-carbinol derivatives

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The association between ambient fine particulate matter and incident adenocarcinoma subtype of lung cancer

BACKGROUND

Adenocarcinoma (AC) is the most common lung cancer among non-smokers, but few studies have assessed the effect of PM_2.5 on AC among never smokers. The purpose of this study was to assess the association between ambient PM_2.5 and incident lung AC in the Adventist Health and Smog Study-2 (AHSMOG-2), a cohort of 80,044 non-smokers (81% never smokers) followed for 7.5 years (597,177 person-years) (2002-2011).

METHODS

Incident lung AC was identified through linkage with U.S. state cancer registries. Ambient PM_2.5 levels at subjects' residences were estimated for the years 2000 and 2001, immediately prior to study start.

RESULTS

A total of 164 incident lung AC occurred during follow-up. Each 10 μg/m³ increment in PM_2.5 was associated with an increase in the hazard rate of lung AC [HR = 1.31 (95% confidence interval (CI) 0.87-1.97)] in the single-pollutant model. Excluding those with prevalent non-melanoma skin cancer (NMSC) strengthened the association with lung AC (HR = 1.62 (95% CI, 1.11-2.36) for each 10 μg/m³ PM_2.5 increment. Also, limiting the analyses to subjects who spent more than 1 h/day outdoors, increased the estimate (HR = 1.55, 95% CI: 1.05, 2.30).

CONCLUSIONS

Increased risk of AC was observed for each 10 μg/m³ increment in ambient PM_2.5 concentrations. The risk was higher among those without prevalent NMSC and those who spent more than 1 h/day outdoors.

Cancer incidence attributable to insufficient fruit and vegetable consumption in Alberta in 2012

BACKGROUND

Sufficient fruit and vegetable consumption (≥ 5 servings/d) has been associated with a probable decreased risk for cancers of the oral cavity, pharynx, larynx, esophagus, stomach and lung (fruit only). The purpose of this study was to estimate the proportion and absolute number of cancer cases in Alberta in 2012 that were attributable to insufficient fruit and vegetable consumption.

METHODS

The numbers and proportions of cancers attributable to insufficient fruit and vegetable consumption were estimated using the population attributable risk. Relative risks were obtained from international collaborative panels and peer-reviewed literature. Prevalence data for insufficient fruit and vegetable consumption in Alberta were obtained from the Canadian Community Health Survey (2003, 2004, 2005, 2007/08). Age-, site- and sex-specific cancer incidence data for 2012 were obtained from the Alberta Cancer Registry.

RESULTS

The proportion of men consuming 5 or more servings of fruits and vegetables per day ranged from 25.9%-30.4% across age groups; the range among women was 46.8%-51.5% across age groups. The proportion of cancers attributable to insufficient fruit and vegetable consumption in Alberta was highest for esophageal cancer (40.0%) and lowest for lung cancer (3.3%). Overall, 290 cancer cases (1.8%) in Alberta in 2012 were attributable to insufficient fruit and vegetable consumption.

INTERPRETATION

Almost 2% of cancers in Alberta can be attributed to insufficient fruit and vegetable consumption. A diet rich in fruits and vegetables has benefits for the prevention of cancer and other chronic diseases; thus, increasing the proportion of Albertans who meet cancer prevention guidelines for fruit and vegetable consumption is a priority.

Polyphenol-rich strawberry extract (PRSE) shows in vitro and in vivo biological activity against invasive breast cancer cells

We describe the biological effects of a polyphenol-rich strawberry extract (PRSE), obtained from the “Alba” variety, on the highly aggressive and invasive basal-like breast cancer cell line A17. Dose-response and time-course experiments showed that PRSE is able to decrease the cellular viability of A17 cells in a time- and dose-dependent manner. PRSE effect on cell survival was investigated in other tumor and normal cell lines of both mouse and human origin, demonstrating that PRSE is more active against breast cancer cells. Cytofluorimetric analysis of A17 cells demonstrated that sub-lethal doses of PRSE reduce the number of cells in S phase, inducing the accumulation of cells in G1 phase of cell cycle. In addition, the migration of A17 cells was studied monitoring the ability of PRSE to inhibit cellular mobility. Gene expression analysis revealed the modulation of 12 genes playing different roles in the cellular migration, adhesion and invasion processes. Finally, in vivo experiments showed the growth inhibition of A17 cells orthotopically transplanted into FVB syngeneic mice fed with PRSE. Overall, we demonstrated that PRSE exerts important biological activities against a highly invasive breast cancer cell line both in vitro and in vivo suggesting the strawberry extracts as preventive/curative food strategy.

Apple intake and cancer risk: a systematic review and meta-analysis of observational studies

OBJECTIVE

Conflicting results on the association between fruit consumption and cancer risk have been reported. Little is known about the cancer preventive effects of different fruit types. The present meta-analysis investigates whether an association exists between apple intake and cancer risk.

DESIGN

Relevant observational studies were identified by literature search (PubMed, Web of Science and Embase). A random-effect model was used to estimate the cancer risk in different anatomical sites. Between-study heterogeneity and publication bias were assessed using adequate statistical tests.

RESULTS

Twenty case-control (three on lung, five on colorectal, five on breast, two on oesophageal, three on oral cavity, two on prostate and one each on pancreas, bladder, larynx, ovary, kidney and brain cancer) and twenty-one cohort (seven on lung, two on colorectal, three on breast and one each on oesophageal, pancreas, bladder, kidney, endometrial, head-neck, urothelial and stomach cancer) studies met the inclusion criteria. Comparing the highest v. lowest level of apple consumption, the reduction of lung cancer risk was statistically highly significant in both case-control (OR=0·75; 95% CI 0·63, 0·88; P=0·001, I 2=0 %) and cohort studies (relative risk=0·89; 95% CI 0·84, 0·94; P<0·001, I 2=53 %). Instead, in the case of colorectal (OR=0·66; 95% CI 0·54, 0·81; P<0·001, I 2=55%), breast (OR=0·79; 95% CI 0·73, 0·87; P<0·001, I 2=1 %) and overall digestive tract (OR=0·50; 95% CI 0·36, 0·69; P<0·001, I 2=90 %) cancers a significant preventive effect of apples was found only in case-control studies while prospective studies indicated no effect. No evidence of publication bias could be detected for colorectal, oral cavity, oesophageal and breast cancer. However, some confounding effects may be present and related to the consumption of other fruit which have not been considered as adjusting factors.

CONCLUSIONS

The present meta-analysis indicates that consumption of apples is associated with a reduced risk of cancer in different anatomical sites.

Fruit and vegetables and cancer risk: a review of southern European studies

High intakes of fruit and vegetables may reduce the risk of cancer at several sites. Evidence has been derived mainly from case-control studies. We reviewed the relationship between consumption of vegetables and fruit and the risk of several common cancers in a network of Italian and Swiss case-control studies including over 10,000 cases of fourteen different cancers and about 17,000 controls. Data were suggestive of a protective role of vegetable intake on the risk of several common epithelial cancers. OR for the highest compared with the lowest levels of consumption ranged from 0.2 (larynx, oral cavity and pharynx) to 0.9 (prostate). Inverse associations were found for both raw and cooked vegetables, although for upper digestive tract cancers the former were somewhat stronger. Similar inverse associations were found for cruciferous vegetables. Frequent consumption of allium vegetables was also associated with reduced risk of several cancers. Fruit was a favourable correlate of the risk of several cancers, particularly of the upper digestive tract, with associations generally weaker than those reported for vegetables. A reduced risk of cancers of the digestive tract and larynx was found for high consumption of citrus fruit. Suggestive protections against several forms of cancer, mainly digestive tract cancers, were found for high consumption of apples and tomatoes. High intakes of fibres, flavonoids and proanthocyanidins were inversely related to various forms of cancer. In conclusion, data from our series of case-control studies suggested a favourable role of high intakes of fruit and vegetables in the risk of many common cancers, particularly of the digestive tract. This adds evidence to the indication that aspects of the Mediterranean diet may have a favourable impact not only on CVD, but also on several common (epithelial) cancers, particularly of the digestive tract.

Dietary habits of lung cancer patients from the Lower Silesia region of Poland

AIM OF THE STUDY

Assessment of lung cancer patients' dietary habits before treatment enable medical staff to provide more individual, precise and complex care to patients, taking into consideration their nutritional status. The aim of this study was, therefore, to evaluate dietary habits related to lung cancer risk of lung cancer patients in comparison with controls from the Lower Silesia region of Poland.

MATERIAL AND METHODS

Assessments of dietary habits, based on a validated questionnaire related to lung cancer risk were performed on 92 lung cancer patients and compared with the results obtained in 157 controls. Dietary patterns were evaluated concerning on eating frequency of high- and low- glycemic index products, vegetables and fruits, vegetable and fruit juices, green tea, liquid dairy products, meat and fried products over the previous year. Alcohol consumption was assessed on a dichotomous scale (yes or no).

RESULTS

Majority of patients had inappropriate dietary habits, such as low consumption of low GI cereal products, vegetables, fruit and green tea, and a high consumption frequency of fried products.

CONCLUSIONS

Reported dietary mistakes indicate the need for dietary education among people at lung cancer risk and with newly diagnosed disease, to enhance their nutritional status.

Fruits, vegetables and lung cancer risk: a systematic review and meta-analysis

BACKGROUND

Lung cancer is the most common cause of cancer death. Fruits and vegetables containing carotenoids and other antioxidants have been hypothesized to decrease lung cancer risk. As part of the World Cancer Research Fund International Continuous Update Project, we conducted a systematic review and meta-analysis of prospective studies.

METHODS

We searched PubMed and several databases up to December 2014 for prospective studies. We conducted meta-analyses comparing the highest and lowest intakes and dose-response meta-analyses to estimate summary relative risks (RRs) and 95% confidence intervals (CIs), and examine possible non-linear associations. We combined results from the Pooling Project with the studies we identified to increase the statistical power of our analysis.

RESULTS

When comparing the highest with the lowest intakes, the summary RR estimates were 0.86 [95% CI 0.78-0.94; n (studies) = 18] for fruits and vegetables, 0.92 (95% CI 0.87-0.97; n = 25) for vegetables and 0.82 (95% CI 0.76-0.89; n = 29) for fruits. The association with fruit and vegetable intake was marginally significant in current smokers and inverse but not significant in former or never smokers. Significant inverse dose-response associations were observed for each 100 g/day increase: for fruits and vegetables [RR: 0.96; 95% CI 0.94-0.98, I(2) = 64%, n = 14, N (cases) = 9609], vegetables (RR: 0.94; 95% CI 0.89-0.98, I(2) = 48%, n = 20, N = 12 563) and fruits (RR: 0.92; 95% CI 0.89-0.95, I(2) = 57%, n = 23, N = 14 506). Our results were consistent among the different types of fruits and vegetables. The strength of the association differed across locations. There was evidence of a non-linear relationship (P < 0.01) between fruit and vegetable intake and lung cancer risk showing that no further benefit is obtained when increasing consumption above ∼400 g per day.

CONCLUSIONS

Eliminating tobacco smoking is the best strategy to prevent lung cancer. Although residual confounding by smoking cannot be ruled out, the current evidence from prospective studies is consistent with a protective role of fruit and vegetables in lung cancer aetiology.

Inhibitory Effect of Genistein on PLC/PRF5 Hepatocellular Carcinoma Cell Line

BACKGROUND

Natural compounds including flavonoids like genistein (GE) are able to inhibit cell proliferation and induce apoptosis. GE is the main representative of these groups. GE inhibits carcinogenic tumors such as colon, stomach, lung, and pancreas tumors. The aim of the present study was to analyze the apoptotic effect of GE in the hepatocellular carcinoma (HCC) PLC/PRF5 cell line.

METHODS

Cells were treated with various doses of GE (1, 5, 10, 25, 50, 75, and 100 μM/L) at different times (24, 48, and 72 h) and the MTT assay was commonly used. Furthermore, cells were treated with single dose of GE (25 μM) at different times and flow cytometry was performed.

RESULTS

GE inhibited the growth of liver cancer cells significantly with a time- and dose-dependent manner. The percentage of living cells in GE treatment groups with a concentration of 25 μM at different times were 53, 48 and 47%, respectively (P < 0.001). Result of flow cytometry demonstrated that GE at a 25 μM concentration induces apoptosis significantly in a time-dependent manner. The percentage of apoptotic cells at different times were 44, 56, and 60%, respectively (P < 0.001).

CONCLUSIONS

GE can significantly inhibit the growth of HCC cells and plays a significant role in apoptosis of this cell line.

Dietary Sulforaphane in Cancer Chemoprevention: The Role of Epigenetic Regulation and HDAC Inhibition

SIGNIFICANCE

Sulforaphane, produced by the hydrolytic conversion of glucoraphanin after ingestion of cruciferous vegetables, particularly broccoli and broccoli sprouts, has been extensively studied due to its apparent health-promoting properties in disease and limited toxicity in normal tissue. Recent Studies: Recent identification of a sub-population of tumor cells with stem cell-like self-renewal capacity that may be responsible for relapse, metastasis, and resistance, as a potential target of the dietary compound, may be an important aspect of sulforaphane chemoprevention. Evidence also suggests that sulforaphane may target the epigenetic alterations observed in specific cancers, reversing aberrant changes in gene transcription through mechanisms of histone deacetylase inhibition, global demethylation, and microRNA modulation.

CRITICAL ISSUES

In this review, we discuss the biochemical and biological properties of sulforaphane with a particular emphasis on the anticancer properties of the dietary compound. Sulforaphane possesses the capacity to intervene in multistage carcinogenesis through the modulation and/or regulation of important cellular mechanisms. The inhibition of phase I enzymes that are responsible for the activation of pro-carcinogens, and the induction of phase II enzymes that are critical in mutagen elimination are well-characterized chemopreventive properties. Furthermore, sulforaphane mediates a number of anticancer pathways, including the activation of apoptosis, induction of cell cycle arrest, and inhibition of NFκB.

FUTURE DIRECTIONS

Further characterization of the chemopreventive properties of sulforaphane and its capacity to be selectively toxic to malignant cells are warranted to potentially establish the clinical utility of the dietary compound as an anti-cancer compound alone, and in combination with clinically relevant therapeutic and management strategies.

Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews

Associations between food and beverage groups and the risk of diet-related chronic disease (DRCD) have been the subject of intensive research in preventive nutrition. Pooled/meta-analyses and systematic reviews (PMASRs) aim to better characterize these associations. To date, however, there has been no attempt to synthesize all PMASRs that have assessed the relationship between food and beverage groups and DRCDs. The objectives of this review were to aggregate PMASRs to obtain an overview of the associations between food and beverage groups (n = 17) and DRCDs (n = 10) and to establish new directions for future research needs. The present review of 304 PMASRs published between 1950 and 2013 confirmed that plant food groups are more protective than animal food groups against DRCDs. Within plant food groups, grain products are more protective than fruits and vegetables. Among animal food groups, dairy/milk products have a neutral effect on the risk of DRCDs, while red/processed meats tend to increase the risk. Among beverages, tea was the most protective and soft drinks the least protective against DRCDs. For two of the DRCDs examined, sarcopenia and kidney disease, no PMASR was found. Overweight/obesity, type 2 diabetes, and various types of cardiovascular disease and cancer accounted for 289 of the PMASRs. There is a crucial need to further study the associations between food and beverage groups and mental health, skeletal health, digestive diseases, liver diseases, kidney diseases, obesity, and type 2 diabetes.

Dietary intake and adherence to the 2010 Dietary Guidelines for Americans among individuals with chronic spinal cord injury: a pilot study

OBJECTIVE

To investigate dietary intake and adherence to the 2010 Dietary Guidelines for Americans in individuals with chronic spinal cord injury (SCI) and able-bodied individuals.

DESIGN

A pilot study of dietary intake among a sample of individuals with SCI >1 year ago from a single site compared with able-bodied individuals.

PARTICIPANTS/METHODS

One hundred black or white adults aged 38-55 years old with SCI >1 year and 100 age-, sex-, and race-matched adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary intake was assessed by the CARDIA dietary history. Linear regression analysis was used to compare dietary intake between the subjects with SCI and those enrolled in the CARDIA study. Further, adherence to the 2010 Dietary Guidelines for dairy, fruits, and vegetables, and whole-grain foods was assessed.

RESULTS

Compared with CARDIA participants, participants with SCI consumed fewer daily servings of dairy (2.10 vs. 5.0, P < 0.001), fruit (2.01 vs. 3.64, P = 0.002), and whole grain foods (1.20 vs. 2.44 P = 0.007). For each food group, fewer participants with SCI met the recommended servings compared with the CARDIA participants. Specifically, the participants with SCI and in CARDIA who met the guidelines were, respectively: dairy, 22% vs. 54% (P < 0.001), fruits and vegetables 39% vs. 70% (P = 0.001), and whole-grain foods 8% vs. 69.6% (P = 0.001).

CONCLUSIONS

Compared with able-bodied individuals, SCI participants consumed fewer daily servings of fruit, dairy, and whole grain foods than proposed by the 2010 Dietary Guideline recommendations. Nutrition education for this population may be warranted.

Joint effects of environmental exposures and familial susceptibility to lung cancer in Chinese never smoking men and women

OBJECTIVES

Previous epidemiological studies had limited power to investigate the joint effects of individual environmental risk factors and familial susceptibility to lung cancer. This study aimed to address this shortcoming.

METHODS

We recruited 345 never smoking lung cancer cases and 828 community referents. We developed a collective environmental exposure index by assigning a value of 1 to subjects at high risks regarding environmental risk factors and 0 otherwise, and then summed over using weights equivalent to the excess odds ratio. Potential additive and multiplicative interactions between environmental exposure index and family cancer history were examined.

RESULTS

Compared with "low environmental exposure and without family cancer history", the odds ratio was 6.80 (95% confidence interval = 3.31-13.98) for males who had high environmental exposures but without family cancer history, whereas it increased to 30.61 (95% confidence interval = 9.38-99.87) if they also had a positive family history. The corresponding associations became weaker in never smoking females. No multiplicative interaction was observed for both genders and an additive interaction was restricted among males.

CONCLUSIONS

This study developed a novel environmental exposure index that offers sufficient interest deserving further studies on the interactions between environmental exposures and familial susceptibility to lung cancer risk.

Fruit and vegetable consumption and lung cancer risk: a case-control study in Galicia, Spain

Lung cancer has multiple risk factors and tobacco is the main one. Diet plays a role, but no clear effect has been consistently observed for different fruit and vegetable consumption. We aim to assess the association between fruit and vegetable consumption and lung cancer risk through a hospital-based case-control study in Spanish population. We recruited incident lung cancer cases in 2 Spanish hospitals from 2004 to 2008. Controls were individuals attending hospital for trivial surgery. Cases and controls were older than 30 and did not have a neoplasic history. We collected information on lifestyle with special emphases on tobacco and dietary habits. We included 371 cases and 496 controls. We found no protective effect for overall fruit consumption. For green leafy vegetables, the odds ratio (OR) was 0.92 [95% confidence interval (CI) = 0.32-2.69), and for other vegetables the OR was 0.77 (95% CI = 0.40-1.48) for the categories compared. We observed a reduced risk for broccoli and pumpkin intake. Although fruit consumption does not seem to be associated with a lower lung cancer risk, only the frequent consumption of specific green leafy vegetables and other vegetables might be associated with a reduced risk of lung cancer.

Multiple therapeutic and preventive effects of 3,3'-diindolylmethane on cancers including prostate cancer and high grade prostatic intraepithelial neoplasia

Cruciferous vegetables belong to the plant family that has flowers with four equal-sized petals in the pattern of a crucifer cross. These vegetables are an abundant source of dietary phytochemicals, including glucosinolates and their hydrolysis products such as indole-3-carbinol (I3C) and 3,3′-diindolylmethane (DIM). By 2013, the total number of natural glucosinolates that have been documented is estimated to be 132. Recently, cruciferous vegetable intake has garnered great interest for its multiple health benefits such as anticancer, antiviral infections, human sex hormone regulation, and its therapeutic and preventive effects on prostate cancer and high grade prostatic intraepithelial neoplasia (HGPIN). DIM is a hydrolysis product of glucosinolates and has been used in various trials. This review is to provide an insight into the latest developments of DIM in treating or preventing both prostate cancer and HGPIN.

Association between folate intake and the risk of lung cancer: a dose-response meta-analysis of prospective studies

Background

Studies have reported inconsistent results regarding the existence of an association between folate intake and the risk of lung cancer. The purpose of this study was to summarize the evidence from prospective cohort studies regarding this relationship by using a dose-response meta-analytic approach.

Methodology and Principal Findings

In September 2013, we performed electronic searches in PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate intake on the incidence of lung cancer. Only prospective cohort studies that reported the effect estimates about the incidence of lung cancer with 95% confidence intervals (CIs) for more than 2 categories of folate intake were included. Overall, we examined 9 cohort studies reporting the data of 566,921 individuals. High folate intake had little effect on the risk of lung cancer (risk ratio [RR], 0.92; 95% CI, 0.84–1.01; P = 0.076). Dose-response meta-analysis also suggested that a 100 µg/day increase in folate intake had no significant effect on the risk of lung cancer (RR, 0.99; 95% CI, 0.97–1.01; P = 0.318). Subgroup analysis suggested that the potential protective effect of low folate intake (100–299 µg/day) was more evident in women than men, while the opposite was true of high folate intake (>400 µg/day). Finally, subgroup analyses of a 100 µg/day increment in folate intake indicated that its potential protective effect was more evident in men than in women.

Conclusion/Significance

Our study revealed that folate intake had little or no effect on the risk of lung cancer. Subgroup analyses indicated that an increased folate intake was associated with a reduced risk of lung cancer in men. Furthermore, low folate intake may be a protective factor for women, and high folate intake for men.

Lung cancer correlates in Lebanese adults: a pilot case--control study

BACKGROUND

Lung cancer is one of the most prevalent types of cancers. However, there are no epidemiological studies concerning lung cancer and its risk factors in Lebanon. This study was carried out to determine the association between lung cancer and its most common risk factors in a sample of the Lebanese population.

METHODS

A hospital-based case-control study was conducted. Patients were recruited in a tertiary health care center. A questionnaire in Arabic was designed to assess the possible risk factors for lung cancer.

RESULTS

For females, cigarette smoking (ORa=9.76) and using fuel for heating (ORa=9.12) were found to be the main risk factors for lung cancer; for males, cigarette smoking (ORa=156.98), living near an electricity generator (ORa=13.26), consuming low quantities of fruits and vegetables (ORa=10.54) and a family history of cancer (ORa=8.75) were associated with lung cancer. Waterpipe smoking was significantly correlated with lung cancer in the bivariate analysis.

CONCLUSION

In this pilot study, it was found that in addition to smoking, outdoor and indoor pollution factors were potential risk factors of lung cancer. Additional studies would be necessary to confirm these findings.

Lung cancer: what are the links with oxidative stress, physical activity and nutrition

Oxidative stress appears to play an essential role as a secondary messenger in the normal regulation of a variety of physiological processes, such as apoptosis, survival, and proliferative signaling pathways. Oxidative stress also plays important roles in the pathogenesis of many diseases, including aging, degenerative disease, and cancer. Among cancers, lung cancer is the leading cause of cancer in the Western world. Lung cancer is the commonest fatal cancer whose risk is dependent on the number of cigarettes smoked per day as well as the number of years smoking, some components of cigarette smoke inducing oxidative stress by transmitting or generating oxidative stress. It can be subdivided into two broad categories, small cell lung cancer and non-small-cell lung cancer, the latter is the most common type. Distinct measures of primary and secondary prevention have been investigated to reduce the risk of morbidity and mortality caused by lung cancer. Among them, it seems that physical activity and nutrition have some beneficial effects. However, physical activity can have different influences on carcinogenesis, depending on energy supply, strength and frequency of exercise loads as well as the degree of exercise-mediated oxidative stress. Micronutrient supplementation seems to have a positive impact in lung surgery, particularly as an antioxidant, even if the role of micronutrients in lung cancer remains controversial. The purpose of this review is to examine lung cancer in relation to oxidative stress, physical activity, and nutrition.

Notch inhibitors for cancer treatment

Notch signaling is an evolutionarily conserved cell signaling pathway involved in cell fate during development, stem cell renewal and differentiation in postnatal tissues. Roles for Notch in carcinogenesis, in the biology of cancer stem cells and tumor angiogenesis have been reported. These features identify Notch as a potential therapeutic target in oncology. Based on the molecular structure of Notch receptor, Notch ligands and Notch activators, a set of Notch pathway inhibitors have been developed. Most of these inhibitors had shown anti-tumor effects in preclinical studies. At the same time, the combinatorial effect of these inhibitors with current chemotherapeutical drugs is still under study in different clinical trials. In this review, we describe the basics of Notch signaling and the role of Notch in normal and cancer stem cells as a logic way to develop different Notch inhibitors and their current stage of progress for cancer patient's treatment.

Intakes of fruits, vegetables, and related vitamins and lung cancer risk: results from the Shanghai Men's Health Study (2002-2009)

Most epidemiological studies evaluating the association of fruit and vegetable intakes on lung cancer risk were conducted in North American and European countries. We investigated the association of intakes of fruits, vegetables, dietary vitamins A and C, and folate with lung cancer risk among 61,491 adult Chinese men who were recruited into the Shanghai Men's Health Study, a population-based, prospective cohort study. Baseline dietary intake was assessed through a validated food frequency questionnaire during in-home visits. Multivariate Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of lung cancer risk associated with dietary intakes. During a median follow-up of 5.5 yr, 359 incident lung cancer cases accrued after the first year of follow-up and 68.8% of them were current smokers. Intakes of green leafy vegetables, β-carotene-rich vegetables, watermelon, vitamin A, and carotenoids were inversely associated with lung cancer risk; the corresponding HR (95% CI) comparing the highest with the lowest quartiles were 0.72 (0.53-0.98), 0.69 (0.51-0.94), 0.65 (0.47-0.90), 0.63 (0.44-0.88), and 0.64 (0.46-0.88). Intake of all fruits and vegetables combined was marginally associated with lower risk. Our study suggests that the consumption of carotenoid-rich vegetables is inversely associated with lung cancer risk.

Current evidence on healthy eating

Large nutritional epidemiology studies, with long-term follow-up to assess major clinical end points, coupled with advances in basic science and clinical trials, have led to important improvements in our understanding of nutrition in primary prevention of chronic disease. Although much work remains, sufficient evidence has accrued to provide solid advice on healthy eating. Good data now support the benefits of diets that are rich in plant sources of fats and protein, fish, nuts, whole grains, and fruits and vegetables; that avoid partially hydrogenated fats; and that limit red meat and refined carbohydrates. The simplistic advice to reduce all fat, or all carbohydrates, has not stood the test of science; strong evidence supports the need to consider fat and carbohydrate quality and different protein sources. This article briefly summarizes major findings from recent years bearing on these issues.

What proportion of lung cancer in never-smokers can be attributed to known risk factors?

Though tobacco smoking is the primary risk factor for lung cancer, a significant fraction of lung cancer deaths occur in lifetime nonsmokers. In this article, we calculate the burden of lung cancer in never-smokers attributable to previously identified risk factors in North America, Europe and China, using population-based estimates of exposure prevalence and estimates of relative risk derived from recently published meta-analyses. Population attributable fractions (PAFs) for individual risk factors ranged from 0.40 to 19.93%. Because of differences in the prevalence of exposures, the PAFs associated with several of the risk factors varied greatly by geographical region. Exposure to the selected risk factors appeared to explain a much larger proportion of lung cancer cases in never-smokers in China than in Europe and North America. Our results demonstrate the geographic variability of the epidemiology of lung cancer in never-smokers and highlight the need for further research in this area, particularly in Europe and North America.

Greater intake of fruit and vegetables is associated with lower risk of nasopharyngeal carcinoma in Chinese adults: a case-control study

PURPOSE

The effect of fruit and vegetable intake on the risk of nasopharyngeal carcinoma (NPC) remains uncertain due to limited published evidence. We performed a matched case-control study to investigate the relationship between the intake of fruit and vegetables and the risk of NPC.

METHODS

Between July 2009 and March 2011, 600 (448 male, 152 female), NPC incident cases from a single hospital in Guangzhou, Guangdong Province, China, a high-incidence area, were enrolled in the study. 600 controls, matched by gender, age (± 3 years) and household type (urban/rural) were also enrolled. Face-to-face interviews were used to collect habitual dietary intakes and information on various covariates.

RESULTS

Multivariate conditional logistic regression analyses showed significant, dose-dependent inverse associations between the intake of vegetables, fruit or a combination of the two and the risk of NPC, even after adjustments for social-economic status, body mass index, dietary factors and other potential covariates. The adjusted odds ratios (95% confidence intervals) for NPC in the top quartile of vegetable intake, fruit intake or a combination of the two, as compared to the lowest quartile, were 0.33 (0.22-0.50), 0.70 (0.47-1.04) and 0.37 (0.25-0.55), respectively. Dark green leafy vegetables, carrots, peppers and tomatoes, citrus fruit and pome fruit showed much more pronounced benefits with regards to NPC than other types of fruit and vegetables. Interaction analyses demonstrated that the effects of total combined vegetable and fruit intake were much more significant in subjects with a higher education level (p interaction: 0.027), and the benefits of fruit were observed in males, but not in females (p interaction: 0.088).

CONCLUSION

Our findings suggest that a greater consumption of fruit and vegetables may lower the risk of NPC in Chinese adults.

Suppression of oxidative stress by grape seed supplementation in rats

Polyphenol-rich grape seeds have a beneficial effect on human health. The present study was performed to investigate the effects of grape seeds on antioxidant activities in rats. Male Sprague-Dawley rats were randomly divided into a control diet group (C), a high-fat diet group (HF), a 5% grape seed-supplemented control diet group (G), and a 5% grape seed-supplemented high-fat diet group (HG). Dietary supplementation with grape seeds reduced serum concentrations of lipid peroxides compared with those in the C and HF groups. The hepatic level of lipid peroxides decreased significantly in the grape seed groups compared with that in the C and HF groups. Superoxide dismutase activity in the G group increased significantly compared with that in the C group. Catalase activity tended to be higher by feeding grape seeds. The grape seed diet increased glutathione peroxidase activity in the C group. Glutathione-S-transferase activity increased significantly in the G group compared with that in the C group. Hepatic content of total glutathione increased significantly in the HG group but decreased significantly in the HF group. The ratio of reduced glutathione and oxidized glutathione increased by feeding the grape seed diet. Total vitamin A concentration was significantly higher in HG group than in other groups. Liver tocopherol content of the G and HG groups was significantly higher than that of the control groups. These results suggest that dietary supplementation with grape seeds is beneficial for suppressing lipid peroxidation in high fat-fed rats.

A randomized experiment to examine unintended consequences of dietary supplement use among daily smokers: taking supplements reduces self-regulation of smoking

AIMS

We examined whether smokers' use of dietary supplements (e.g. vitamin C, multi-vitamins) induces illusory invulnerability that in turn disinhibits smoking. Such supplement use may be perceived as conferring health credentials.

DESIGN

  A single-factor (credentials: with or without) between-subjects design was employed. Smokers were assigned randomly to take either a known placebo pill or a dietary supplement (in fact, the same placebo) in an ostensible health-food test.

SETTING

  Laboratory at Kaohsiung Medical University, Taiwan.

PARTICIPANTS

  Study 1 involved of a student sample consisting of 74 daily smokers, whereas study 2 involved a community sample consisting of 80 daily smokers.

MEASUREMENTS

  In Study 1, participants reported their perceived invulnerability following the manipulation. In study 2, pre- and post-test measures of invulnerability were administered, and attitudes towards dietary supplements were assessed prior to the manipulation. In both studies, the dependent measure was the number of cigarettes smoked during completion of an unrelated survey.

FINDINGS

  Participants who believed that they were taking a dietary supplement smoked more cigarettes than did controls. Study 1 found support for the role of perceived invulnerability as a mechanism underlying this effect. Study 2 demonstrated the moderating effect played by attitudes towards dietary supplements: a more positive attitude towards supplements increased susceptibility to licensing effects.

CONCLUSIONS

  Dietary supplement use may create illusory invulnerability, reducing the self-regulation of smoking. Reminding health-conscious smokers that multi-vitamins do not prevent cancer may help such smokers to control their smoking and encourage them to stop.

Methylenetetrahydrofolate reductase polymorphisms and interaction with smoking and alcohol consumption in lung cancer risk: a case-control study in a Japanese population

Background

Cigarette smoking is an established risk factor of lung cancer development while the current epidemiological evidence is suggestive of an increased lung cancer risk associated with alcohol consumption. Dietary folate, which is present in a wide range of fresh fruits and vegetables, may be a micronutrient that has a beneficial impact on lung carcinogenesis. Methylenetetrahydrofolate reductase (MTHFR) plays a crucial role in regulating folate metabolism, which affects both DNA synthesis/repair and methylation. We examined if smoking or alcohol consumption modify associations between MTHFR polymorphisms and lung cancer risk.

Methods

We evaluated the role of the MTHFR C677T (rs1801133) and A1298C (rs1801131) polymorphisms in a case-control study comprised of 462 lung cancer cases and 379 controls in a Japanese population. Logistic regression was used to assess the adjusted odds ratios (OR) and 95% confidence intervals (95% CI).

Results

The TT genotype of the C677T polymorphism was significantly associated with an increased risk of lung cancer (OR = 2.27, 95% CI = 1.42 - 3.62, P < 0.01) while the A1298C polymorphism was not associated with lung cancer risk. The minor alleles of both polymorphisms behaved in a recessive fashion. The highest risks were seen for 677TT-carriers with a history of smoking or excessive drinking (OR = 6.16, 95% CI = 3.48 - 10.9 for smoking; OR = 3.09, 95% CI = 1.64 - 5.81 for drinking) compared with C-carriers without a history of smoking or excessive drinking, but no interactions were seen. The 1298CC genotype was only associated with increased risk among non-smokers (P < 0.05), and smoking was only associated with increased risks among 1298A-carriers (P < 0.01), but no significant interaction was seen. There was a synergistic interaction between the A1298C polymorphism and drinking (P < 0.05). The highest risk was seen for the CC-carriers with excessive drinking (OR = 7.24, 95% CI = 1.89 - 27.7) compared with the A-carriers without excessive drinking).

Conclusions

The C677T polymorphism was significantly associated with lung cancer risk. Although the A1298C polymorphism was not associated with lung cancer risk, a significant interaction with drinking was observed. Future studies incorporating data on folate intake may undoubtedly lead to a more thorough understanding of the role of the MTHFR polymorphisms in lung cancer development.

Induction of cancer cell death by isoflavone: the role of multiple signaling pathways

Soy isoflavones have been documented as dietary nutrients broadly classified as "natural agents" which plays important roles in reducing the incidence of hormone-related cancers in Asian countries, and have shown inhibitory effects on cancer development and progression in vitro and in vivo, suggesting the cancer preventive or therapeutic activity of soy isoflavones against cancers. Emerging experimental evidence shows that isoflavones could induce cancer cell death by regulating multiple cellular signaling pathways including Akt, NF-κB, MAPK, Wnt, androgen receptor (AR), p53 and Notch signaling, all of which have been found to be deregulated in cancer cells. Therefore, homeostatic regulation of these important cellular signaling pathways by isoflavones could be useful for the activation of cell death signaling, which could result in the induction of apoptosis of both pre-cancerous and/or cancerous cells without affecting normal cells. In this article, we have attempted to summarize the current state-of-our-knowledge regarding the induction of cancer cell death pathways by isoflavones, which is believed to be mediated through the regulation of multiple cellular signaling pathways. The knowledge gained from this article will provide a comprehensive view on the molecular mechanism(s) by which soy isoflavones may exert their effects on the prevention of tumor progression and/or treatment of human malignancies, which would also aid in stimulating further in-depth mechanistic research and foster the initiation of novel clinical trials.