Diet and risk of cancer of the upper aerodigestive tract—II. Nutrients

112

103

We examined the association between whole-grain intake and incident upper aerodigestive tract cancer in a cohort of 34,651 postmenopausal, initially cancer-free women. We also studied established risk factors for upper aerodigestive cancers, including fruit and vegetable intake, smoking and alcohol intake. A mailed questionnaire at baseline in 1986 included a food-frequency questionnaire and assessment of other cancer risk factors. During the 14-year follow-up period, 169 Studies that have considered the role of dietary factors with regard to cancers of the upper aerodigestive tract have generally reported inverse associations with intake of fruit and vegetables, 1-7 and whole grains. 8,9 Several studies support the idea that wholegrain intake is associated with reduced risk of gastric cancers. 10 Studies that included grain fiber as a predictor 11,12 further bolster the idea that whole grain may protect against upper aerodigestive tract cancers. Previous studies of upper aerodigestive cancers have been case-control in design and, therefore, potentially subject to recall bias.The mechanism of the apparent protective effect of fruits, vegetables and whole grains against upper aerodigestive cancers remains unclear. It may be a result of their fiber content, antioxidant content or some other phytochemicals. Clarification of the protective mechanisms of fruits, vegetables and whole grains is important to our understanding of cancers of the upper aerodigestive tract. In an analysis of the Iowa Women's Health Study (IWHS), a prospective cohort study of initially 55-to 69-year old women living in Iowa, Zheng et al. 13 reported lower dietary intake of yellow/orange vegetables and of carotene, vitamins C and E and retinol in the 59 women who developed upper digestive tract cancers between 1986 and 1992.Our primary focus was to study whether, after 14 years of follow-up in the IWHS, whole-grain intake is related to reduced risk of upper aerodigestive tract cancers. At the same time, we reviewed evidence for the established lifestyle risk factors: low fruit and vegetable intake, smoking and alcohol intake. To address potential mechanisms, we considered the roles of fiber and specific micronutrients in the risk of upper digestive tract neoplasms. MATERIAL AND METHODSA detailed description of the methodology of the IWHS has been published elsewhere. 14 Briefly, participants in the IWHS were a random sample of women aged 55-69 years from the 1985 Iowa driver's license list. A total of 41,836 women responded to a mail survey in January 1986 (42.7% response rate). Using information from the driver's license list and the 1980 U.S. census, it was determined that responders were about 3 months older than nonresponders, 0.4 kg/m 2 lighter and slightly more likely to live in rural, less affluent counties. Nonresponders had somewhat higher rates of smoking-related diseases. 14 Women were excluded from the analysis if they left 30 or more items blank on the foodfrequency questionnaire or reported implausibly high or low energy intak...

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Dietary risk factors for upper aerodigestive tract cancers

Kasum

Jacobs

Nicodemus

et al. 2002

112

103

“…As a result, 15 articles reporting 20 studies including 3955 esophageal cancer cases and 7063 controls were selected for the meta-analysis. 13,[24][25][26][27][28][29][30][31][32][33][34][35][36][37] The detailed processes of our literature search are shown in Figure 1. The main characters of these studies are presented in Table 1.…”

Section: Literature Search and Study Characteristicsmentioning

confidence: 99%

Association between dietary vitamin C intake and risk of esophageal cancer: A dose–response meta‐analysis

Lü²,

Zhao

et al. 2015

While several epidemiological studies have investigated the association between vitamin C and risk of esophageal cancer, the results remain inconsistent. In the present study, a meta-analysis was conducted to assess the impact of dietary vitamin C intake on esophageal cancer risk. Online databases were searched up to March 29, 2015, for studies on the association between dietary vitamin C intake and esophageal cancer risk. Pooled risk ratios (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Dose-response analyses were performed using the method of restricted cubic splines with four knots at percentiles of 5, 35, 65 and 95% of the distribution. Publication bias was estimated using Egger's tests and funnel plots. In all, 15 articles were included in this meta-analysis, including 20 studies, containing 7063 controls and 3955 cases of esophageal cancer. By comparing the highest vs. the lowest categories of vitamin C intake, we found that vitamin C was inversely associated with the risk of esophageal cancer [overall OR 5 0.58, 95% CI 5 0.49-0.68, I 2 5 56%]. A linear dose-response relationship was found. With an increase in dietary vitamin C intake of 50 mg/day, the risk of esophageal cancer statistically decreased by 13% (OR 5 0.87, 95% CI 5 0.80-0.93, p linearity 5 0.0002). In conclusion, our analysis suggested that the higher intake of dietary vitamin C might have a protective effect against esophageal cancer.Esophageal cancer ranks the tenth most common malignancy and the eighth leading cause of cancer-related deaths worldwide. 1 In 2012, [mt]456,000 newly diagnosed cases and 400,000 related deaths were reported. 2 Most esophageal cancer patients are diagnosed at the advanced stages, and the 5-year survival rate is <20%. 3 Thus, primary prevention of esophageal cancer is becoming critical.A large proportion of cases are induced by the action of chemical carcinogens. The epidemiological evidence suggests that alcohol consumption, smoking tobacco, N-nitroso compound and micronutrient deficiency are among the major risk factors for esophageal cancer. [4][5][6] The ultimate reactive and carcinogenic forms of most chemical carcinogens are strong electrophiles. 7 However, vitamin C can prevent carcinogenesis of esophageal cells by blocking the formation of Nnitroso compounds. [8][9][10][11][12] Since the first study that explored the association between vitamin C and esophageal cancer in 1987, 13 a number of epidemiological studies have investigated the relationship between vitamin C intake and esophageal cancer risk. However, these results are controversial. Therefore, we conducted a meta-analysis to assess the association of dietary vitamin C intake and the risk of esophageal cancer, and to evaluate the dose-response relationship of esophageal cancer and vitamin C intake. Material and Methods Search strategyA comprehensive literature search of Pubmed, and Web of Knowledge was conducted before March 2015. The following keywords were used: "esophageal cancer" or...

“…7,8 The lack of comprehensive flavonoid and proanthocyanidin databases for foods 9 has limited epidemiological investigations of their role in esophageal cancer prevention to only 3 case-control studies. [10][11][12] Total flavonoid consumption was inversely associated with esophageal cancer in 1 study 11 but was not associated with ESCC in another. 10 Of 5 major dietary flavonoid classes, only flavanone consumption was inversely associated with ESCC.…”

mentioning

confidence: 93%

Flavonoid consumption and esophageal cancer among black and white men in the United States

Bobe

Peterson

Gridley

et al. 2009

Flavonoids and proanthocyanidins are bioactive polyphenolic components of fruits and vegetables that may account for part of the protective effect of raw fruit and vegetable consumption in esophageal cancer. We studied the relationship between esophageal cancer and dietary proanthocyanidins, flavonoids and flavonoid subclasses (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols and isoflavonoids) using recently developed USDA and Tufts flavonoid and proanthocyanidin databases. The study was a population-based, case-control analysis of 161 white men with esophageal adenocarcinoma (EAC), 114 white and 218 black men with esophageal squamous cell carcinoma (ESCC) and 678 white and 557 black male controls who lived in 3 areas of the United States. Neither total flavonoid nor proanthocyanidin intake was associated with EAC and ESCC in either white or black men. In white men, inverse associations were observed between anthocyanidin intake and EAC (4th vs. 1st quartile odds ratio [OR], 0.47, 95% confidence interval [CI], 0.24-0.91; p trend 5 0.04) and between isoflavonoid intake and ESCC (4th vs. 1st quartile OR, 0.43, 95% CI, 0.20-0.93; p trend 5 0.01). None of the associations remained significant after adjusting for dietary fiber, which is strongly correlated with flavonoid consumption. We conclude that total flavonoids and proanthocyanidins do not have strong protective effects in either EAC or ESCC. Some protective effects were evident in flavonoid subclasses and population subgroups. In white men, foods rich in anthocyanidins may have chemopreventive effects in EAC and those rich in isoflavonoids may do so in ESCC. ' UICCKey words: case-control study; esophageal adenocarcinoma; esophageal squamous cell carcinoma; flavonoids; proanthocyanidins Low raw fruit and vegetable consumption has been associated with increased risk of the 2 primary histological subtypes of esophageal cancer, esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), in both case-control and prospective cohort studies. 1 A population-based case-control study of EAC and ESCC among black and white men in the United States also suggested that these effects might differ between histological subtypes, population subgroups and food groups. 2,3 Flavonoids and proanthocyanidins (condensed tannins) are a group of bioactive polyphenols that are present in raw fruits and vegetables such as citrus fruits, apples and legumes as well as in beverages such as tea, citrus fruit juices and wine. 4,5 They might partially account for the protective effect of high raw fruit and vegetable consumption in EAC and ESCC. The plant sources of the 6 major classes of dietary monomeric flavonoids, such as anthocyanidins, flavan-3-ols (catechins), flavanones, flavones, flavonols and isoflavonoids, differ as do those for proanthocyanidins, oligomers and polymers of flavan-3-ol units. 6 Monomeric flavonoids and proanthocyanidins have anticarcinogenic properties, including antioxidative, antimutagenic, antiinflammatory and antiproliferative ef...