Vegetables, fruit, and antioxidant-related nutrients and risk of non-Hodgkin lymphoma: a National Cancer Institute-Surveillance, Epidemiology, and End Results population-based case-control study

BACKGROUND: Factors related to DNA damage and altered immunologic responses, such as reactive oxygen species production, are associated with the risk of non-Hodgkin lymphoma (NHL). OBJECTIVE: The aim was to evaluate NHL risk with intakes of vegetables, fruit, and nutrients involved in antioxidant activities. DESIGN: Incident case subjects aged 20-74 y were identified between 1998 and 2000 from a National Cancer Institute-sponsored study by using four Surveillance, Epidemiology, and End Results registries. Control subjects, who were selected by random dialing (< 65 y) and from Medicare files (> or = 65 y), were matched to cases by age, center, race, and sex. Of 1321 case and 1057 control subjects who enrolled, dietary data were collected on a subset (466 cases and 391 controls). Carotenoid intakes were estimated by using updated values from the US Department of Agriculture nutrient databases. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% CIs. RESULTS: NHL risk was inversely associated with higher number of weekly servings of all vegetables (multivariable OR for highest compared with lowest quartile: 0.58; 95% CI: 0.35, 0.95; P for trend = 0.04), green leafy vegetables (OR: 0.59; 95% CI: 0.36, 0.96; P for trend = 0.01), and cruciferous vegetables (OR: 0.62; 95% CI: 0.39, 1.00; P for trend = 0.05) and with higher daily intakes of lutein and zeaxanthin (OR: 0.54; 95% CI: 0.32, 0.91; P for trend = 0.06) and zinc (OR: 0.58; 95% CI: 0.36, 0.91; P for trend = 0.02). An effect modification by exercise and NHL subtype was observed with some food groups and nutrients. CONCLUSION: Higher intakes of vegetables, lutein and zeaxanthin, and zinc are associated with a lower NHL risk.     

Intakes of selected nutrients, foods, and phytochemicals and prostate cancer risk in western New York

A number of epidemiological studies have suggested that diet may affect the etiology of prostate cancer, but few have investigated the impact of phytochemical intakes on this cancer. We conducted a case-control study of diet and prostate cancer in western New York involving 433 men with primary, histologically confirmed prostate cancer and 538 population-based controls, frequency matched to cases on age and county of residence. Diet was assessed with a detailed food-frequency questionnaire. We calculated daily intakes of nutrients and the phytochemicals beta-sitosterol, campesterol, stigmasterol, total phytosterols, total lignan precursors, quercetin, and kaempferol based on published food composition data. Odds ratios (ORs) and 95% confidence intervals (CIs) describing the association of prostate cancer risk with selected nutrients, phytochemicals, and food groups were estimated with unconditional logistic regression. Compared with men in the lowest quartile of intake, reduced risks were observed for men in the highest quartile of intake of vitamin C (OR = 0.49; 95% CI = 0.33-0.74), beta-carotene (OR = 0.53; 95% CI = 0.36-0.79), alpha-carotene (OR = 0.67; 95% CI = 0.47-0.97), lutein (OR = 0.55; 95% CI = 0.37-0.81), lycopene (OR = 0.62; 95% CI = 0.42-0.92), total lignan precursors (OR = 0.66; 95% CI = 0.47-0.94), quercetin (OR = 0.64; 95% CI = 0.44-0.92), and total vegetables (OR = 0.53; 95% CI = 0.36-0.79), but weak increased risks were observed for snacks and sweets (OR = 1.46; 95% CI = 0.95-2.23). Estimates associated with nutrients and phytochemicals were attenuated after adjustment for total vegetable intake. Nevertheless, our results support the hypothesis that a phytochemical-rich, plant-based diet is of importance in reducing risks of hormone-related neoplasms.     

Raw and cooked vegetables, fruits, selected micronutrients, and breast cancer risk: a case-control study in Germany

In 1998-2000, a case-control study of breast cancer was conducted in Heidelberg, Germany. Three hundred ten consecutively recruited cases with primary breast cancer were matched according to 10-yr age groups to 353 controls with conditions unrelated to diet or endocrine disorders. Intake of raw vegetables, total vegetables, and whole-grain products was inversely associated with breast cancer risk (highest vs. lowest quartile adjusted odds ratio [OR] 0.51, 95% confidence interval [CI] 0.31-0.84; OR = 0.62, 95% CI = 0.38-1.02; and OR = 0.57; 95% CI = 0.34-0.95, respectively). Also, high intake of some selected vitamins and minerals possessing putative DNA-stabilizing properties displayed significant inverse risk associations. Adjusted ORs were as follows: vitamin C (OR = 0.49, 95% CI = 0.2-0.88), folate equivalents (OR = 0.47, 95% CI = 0.25-0.88), b-carotene (OR = 0.46, 95% CI = 0.27-0.80), zinc (OR = 0.35, 95% CI = 0.15-0.78), and copper (OR = 0.51, 95% CI = 0.31-1.03). In contrast, no significant association with risk was seen for an increased intake of fruits, cooked vegetables, fiber, calcium, manganese, or iron. In this population of German women, components of raw vegetables and some micronutrients appear to decrease breast cancer risk.     

Impact of consumption of vegetable, fruit, grain, and high glycemic index foods on aggressive prostate cancer risk

Prostate cancer is a common but complex disease, and distinguishing modifiable risk factors such as diet for more aggressive disease is extremely important. Previous work has detected intriguing associations between vegetable, fruit, and grains and more aggressive prostate cancer, although these remain somewhat unclear. Here we further investigate such potential relationships with a case-control study of 982 men (470 more aggressive prostate cancer cases and 512 control subjects). Comparing the highest to lowest quartiles of intake, we found that increasing intakes of leafy vegetables were inversely associated with risk of aggressive prostate cancer [adjusted odds ratio (OR) = 0.66, 95% CI: 0.46, 0.96; P trend = 0.02], as was higher consumption of high carotenoid vegetables (OR = 0.71, 95% CI: 0.48, 1.04; P trend = 0.04). Conversely, increased consumption of high glycemic index foods were positively associated with risk of aggressive disease (OR = 1.64, 95% CI: 1.05, 2.57; P trend = 0.02). These results were driven by a number of specific foods within the food groups. Our findings support the hypothesis that diets high in vegetables and low in high glycemic index foods decrease risk of aggressive prostate cancer.     

Dietary antioxidants and lung cancer risk: a case-control study in Uruguay.

To examine the protective role of dietary antioxidants (carotenoids, vitamin C, vitamin E, glutathione, and flavonoids) in lung cancer risk, a case-control study involving 541 cases of lung cancer and 540 hospitalized controls was carried out in Uruguay. The relevant variables were energy adjusted using the residuals method and then categorized in quartiles. Adjusted odds ratios (ORs) for antioxidants were calculated through unconditional logistic regression. With the exception of lycopene and vitamin C, the remaining antioxidants were associated with significant reductions in risk of lung cancer. Of particular interest was the inverse association between dietary glutathione and lung cancer [OR of quartile with highest intake compared with lowest quartile = 0.42, 95% confidence interval (CI) = 0.27-0.63]. Also, carotenoids and vitamin E were associated with significant reductions in risk of lung cancer (OR = 0.43, 95% CI = 0.29-0.64 for total carotenoids and OR = 0.50, 95% CI = 0.39-0.85 for vitamin E). A joint effect for high vs. low intakes of beta-carotene and glutathione was associated with a significant reduction in risk (OR = 0.32, 95% CI = 0.22-0.46). It could be concluded that dietary antioxidants are associated with a significant protective effect in lung carcinogenesis and that the inverse association for glutathione persisted after controlling for total vegetables and fruits.     

Impact of Consumption of Vegetable,Fruit, Grain,and High Glycemic Index Foods on Aggressive Prostate Cancer Risk

Prostate cancer is a common but complex disease, and distinguishing modifiable risk factors such as diet for more aggressive disease is extremely important. Previous work has detected intriguing associations between vegetable, fruit, and grains and more aggressive prostate cancer, although these remain somewhat unclear. Here we further investigate such potential relationships with a case-control study of 982 men (470 more aggressive prostate cancer cases and 512 control subjects). Comparing the highest to lowest quartiles of intake, we found that increasing intakes of leafy vegetables were inversely associated with risk of aggressive prostate cancer [adjusted odds ratio (OR) = 0.66, 95% CI: 0.46, 0.96; P trend = 0.02], as was higher consumption of high carotenoid vegetables (OR = 0.71, 95% CI: 0.48, 1.04; P trend = 0.04). Conversely, increased consumption of high glycemic index foods were positively associated with risk of aggressive disease (OR = 1.64, 95% CI: 1.05, 2.57; P trend = 0.02). These results were driven by a number of specific foods within the food groups. Our findings support the hypothesis that diets high in vegetables and low in high glycemic index foods decrease risk of aggressive prostate cancer.     

Cruciferous vegetables, genetic polymorphisms in glutathione S-transferases M1 and T1, and prostate cancer risk

Cruciferous vegetables contain anticarcinogenic isothiocyanates (ITCs), particularly the potent sulforaphane, which may decrease risk of prostate cancer through induction of phase II enzymes, including glutathione S-transferases (GSTs). We evaluated this hypothesis in a population-based, case-control study of prostate cancer, including 428 men with incident prostate cancer and 537 community controls. An in-person interview included an extensive food-frequency questionnaire. Genotyping for deletions in GSTM1 and GSTT1 was performed in a subset of men who provided blood. Intakes of cruciferous vegetables and of broccoli, the greatest source of sulforaphane, were associated with decreased prostate cancer risk at all levels above the lowest consumers [adjusted 4th quartile odds ratio (OR)=0.58; 95% confidence interval (CI)=0.38, 0.89, and 0.72 (95% CI=0.49, 1.06)], respectively. In relation to genotypes, there was a nonsignificant increase in risk with the GSTT1 null genotype (OR=1.51; 95% CI=0.98, 2.31) but no effects of GSTM1 genotype. However, men with GSTM1-present genotype and high broccoli intake had the greatest reduction in risk (OR=0.49; 95% CI=0.27, 0.89). Our findings provide evidence that two or more servings per month of cruciferous vegetables may reduce risk of prostate cancer, especially among men with GSTM1-present alleles, and are consistent with a role of dietary ITCs as chemopreventive agents against prostate cancer.     

Intakes of selected nutrients and food groups and risk of ovarian cancer

In a hospital-based case-control study, we examined dietary intakes of selected nutrients and food groups and ovarian cancer risk among 496 women with primary, histologically confirmed epithelial ovarian cancer and 1,425 women with nonneoplastic diagnoses, ages 20-87 years, admitted to Roswell Park Cancer Institute between 1982 and 1998. Data on diet and other relevant risk factors in the few years before admission were collected with a self-administered questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression adjusting for age, education, region of residence, regularity of menstruation, family history of ovarian cancer, parity, age at menarche, oral contraceptive use, and energy intake. Women in the highest vs. the lowest quartile of total energy had a weak increase in risk (OR = 1.25, 95% CI = 0.90-1.73). Significantly reduced risks were associated with higher intakes of dietary fiber (OR = 0.57, 95% CI = 0.38-0.87), vitamin A (OR = 0.66, 95% CI = 0.45-0.98), carotenoid (OR = 0.64, 95% CI = 0.43-0.93), vitamin E (OR = 0.58, 95% CI = 0.38-0.88), beta-carotene (OR = 0.68, 95% CI = 0.46-0.98), and total fruit and vegetable intake (OR = 0.62, 95% CI = 0.42-0.92). Our findings suggest that a diet high in plant foods may be important in reducing risk of ovarian cancer.     

Cancer mortality among butchers: a 24-state death certificate study

OBJECTIVE: The objective of this study was to document cancer mortality among American butchers. METHODS: Death certificates collected in 24 American states were used to calculate mortality odds ratios (ORs) and their confidence intervals (CIs) for 18,639 butchers. RESULTS: Butchers experienced an increased mortality of cancer of the oral cavity (OR, 1.40; 95% CI = 1.09-1.81), esophagus (OR, 1.19; 95% CI = 1.01-1.40), pharynx (OR, 1.22; 95% CI = 0.91-1.64), and larynx (OR, 1.19; 95% CI = 0.92-1.54), as well as a reduced mortality from melanoma (OR, 0.70; 95% CI = 0.52-0.94), non-Hodgkin lymphoma (OR, 0.82; 95% CI = 0.69-0.97), and breast cancer (OR, 0.76; 95% CI = 0.58-0.99). CONCLUSIONS: It is likely that occupational exposures experienced by butchers have contributed to the increased risk of cancers of the oral cavity and esophagus.     

Vegetable intake is associated with lower Frammingham risk scores in Korean men: Korea National Health and Nutrition Survey 2007-2009

BACKGROUND/OBJECTIVESObservational studies suggest that an association between vegetable consumption and coronary heart disease (CHD). However, the results are inconsistent. This study aimed to investigate the daily intake of vegetables on a national level and its effect on the risk of CHD risk, as determined by the Framingham Risk Score (FRS).SUBJECTS/METHODSThis study was conducted a cross-sectional design of 2,510 male adults 40-64y of age who participated in the 2007-2009 Korean National Health and Nutrition Examination Survey. Daily intake of vegetable was assessed by 24-h recall, and the consumption frequency of vegetables was determined using a food frequency questionnaire. The odd ratio of CHD risk according to daily intake and frequency of vegetables was analyzed.RESULTSTotal vegetable intake was inversely and significantly associated with the risk of CHD (Model 1: 4th vs. 1st quartile, OR = 0.74, 95% CI = 0.58-0.96, P for trend = 0.0015), and the significant relationship with CHD risk remained even after adjusting for potential confounders (Model 3: 4th vs. 1st quartile, adjusted OR [aOR] = 0.69, 95% CI = 0.49-0.95, P for trend = 0.0492). Subjects in the higher quartiles of non-salted vegetable intake had 31% lower odds of the risk of CHD compared to those in the lowest quartile after adjusting for various potential confounders in model 3 (aOR = 0.69; 95% CI = 0.49-0.97, P for trend = 0.0478). No significant associations between the frequency of vegetable intake (total, green, white and red vegetable) and the risk of CHD were found.CONCLUSIONSThe major results of this study indicate that higher vegetable intake may help prevent CHD in Korean men.     

Breast cancer risk in premenopausal women is inversely associated with consumption of broccoli, a source of isothiocyanates, but is not modified by GST genotype

The role of vegetable consumption in relation to breast cancer risk is controversial. Anticarcinogenic compounds may be present only in specific vegetables, thereby attenuating findings for total vegetable intake. Cruciferous vegetables contain precursors of isothiocyanates (ITCs), which may be chemopreventive through potent inhibition of phase I, and induction of phase II enzymes, such as glutathione S-transferases (GSTs). We investigated associations between consumption of cruciferous vegetables, sources of ITCs, and breast cancer risk, and potential modification of relations by GSTM1 and GSTT1 genotypes. Cases (n = 740) were Caucasian women with incident breast cancer identified from all major hospitals in Erie and Niagara counties. Community controls (n = 810) were frequency matched to cases by age and county. An in-depth interview including a validated FFQ was administered in person. Odds ratios (ORs) and 95% CIs were used to estimate relative risks. Consumption of cruciferous vegetables, particularly broccoli, was marginally inversely associated with breast cancer risk in premenopausal women [4th quartile OR = 0.6, 95% CI (0.40-1.01), P = 0.058]. Associations were weaker or null among postmenopausal women. No significant effects of GST genotype on risk were observed in either menopausal group. These data indicate that cruciferous vegetables may play an important role in decreasing the risk of premenopausal breast cancer.     

A high ratio of dietary n-6/n-3 polyunsaturated fatty acids is associated with increased risk of prostate cancer

Experimental studies suggest omega-3 (n-3) polyunsaturated fatty acids (PUFA) suppress and n-6 PUFA promote prostate tumor carcinogenesis. Epidemiologic evidence remains inconclusive. The objectives of this study were to examine the association between n-3 and n-6 PUFA and prostate cancer risk and determine if these associations differ by race or disease aggressiveness. We hypothesize that high intakes of n-3 and n-6 PUFA will be associated with lower and higher prostate cancer risk, respectively. A case-control study comprising 79 prostate cancer cases and 187 controls was conducted at the Durham VA Medical Center. Diet was assessed using a food frequency questionnaire. Logistic regression analyses were used to obtain odds ratios (ORs) and 95% confidence intervals (95% CI) for the associations between n-3 and n-6 PUFA intakes, the dietary ratio of n-6/n-3 fatty acids, and prostate cancer risk. Our results showed no significant associations between specific n-3 or n-6 PUFA intakes and prostate cancer risk. The highest dietary ratio of n-6/n-3 was significantly associated with elevated risk of high-grade (OR, 3.55; 95% CI, 1.18-10.69; P_trend = 0.03), but not low-grade prostate cancer (OR, 0.95; 95% CI, 0.43-2.17). In race-specific analyses, an increasing dietary ratio of n-6/n-3 fatty acids correlated with higher prostate cancer risk among white men (P_trend = 0.05), but not black men. In conclusion, our findings suggest that a high dietary ratio of n-6/n-3 fatty acids may increase the risk of overall prostate cancer among white men and possibly increase the risk of high-grade prostate cancer among all men.     

Protein and legume intake and prostate cancer mortality in Puerto Rican men

Prostate cancer is the number 1 cancer killer among Puerto Rican (PR) men. Plant foods have been inversely associated with prostate cancer. Legumes play a significant role in the PR diet; consumption of legumes in PR (14 lb/capita) was double that of the United States (7 lb/capita). We examined dietary protein consumption (from baseline 24-h dietary recalls) and prostate cancer mortality in the PR Heart Health Program, a cohort study of 9,824 men aged 35-79 years at baseline (1964) with follow-up until 2005. Total protein intake in the cohort was 85 g/day, and sources of protein were 30% vegetable, 30% dairy, 31% animal, and 8% seafood protein. Legume intake was 2.3 servings/day (1/4 cup each). Legume intake was not associated with prostate cancer mortality [comparing highest quartile to lowest quartile-odds ratio (OR) 1.40 [95% confidence interval (CI) 0.91-2.18], P trend 0.17]-nor were total protein, animal, seafood, dairy, or vegetable protein intakes. Consuming 1-2 servings of fruit was inversely associated (OR 0.50, 95% CI 0.32-0.77), whereas consuming more than 2 servings of fruit was not associated with prostate cancer mortality. Thus, we find no association between legumes or protein intake and prostate cancer mortality in this longitudinal cohort study of PR men.     

膳食因素与宫颈癌关系的病例对照研究

目的　探讨膳食因素与宫颈癌发生的关系。方法　采用以医院为基础的病例对照研究 ,调查山西省肿瘤医院妇科 2 0 0 4年 1～ 5月经病理确诊的宫颈癌新发病例 (n =132 )和同期就诊的良性肿瘤患者 (n =133)的相关因素和膳食情况 ,膳食摄入情况的调查采用半定量食物频数问卷的方法。采用非条件Logistic回归计算各因素与宫颈癌的OR值及其 95 %CI。结果　在调整非膳食因素的影响后发现 ,深色蔬菜 (OR =0 34,95 %CI =0 15～ 0 76 )和膳食叶酸 (OR =0 36 ,95 %CI=0 14～ 0 95 )是宫颈癌发生的保护性因素 ,且存在剂量 -反应关系 (趋势检验P <0 0 1)。结论　宫颈癌的发生可能与膳食因素有关 ,摄入较多的深色蔬菜特别是富含叶酸的食物可能会降低宫颈癌发生的危险性。     

Statin use and the risk of breast and prostate cancer

BACKGROUND: Laboratory data suggest that the cholesterol-lowering "statin" drugs may have chemopreventive potential against cancer at various sites, including breast and prostate. However, in one trial of pravastatin there was a significant excess of breast cancer in the treatment group. In the present study, we assessed the relation of statin use to the risk of breast and prostate cancer in our hospital-based Case-Control Surveillance Study of Drugs and Serious Illnesses. METHODS: Cases were 1,132 women with breast cancer and 1,009 men with prostate cancer; controls were 1,331 women and 1,387 men admitted for conditions unrelated to statin use. We used multivariate unconditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for use of statins compared with no use. RESULTS: The OR for breast cancer among statin users was 1.5 (95% CI = 1.0-2.3), largely accounted for by an OR of 1.8 (95% CI = 0.9-3.6) among cases with carcinoma in situ. Among invasive cases, the OR was 1.2 (95% CI = 0.7-2.0). The odds ratio for prostate cancer overall was 1.2 (95% CI = 0.8-1.7), and it was 1.4 (95% CI = 0.7-2.5) for Stage A. CONCLUSIONS: The data from the present study do not support a protective effect of statins against breast or prostate cancer. Detection bias is a possible explanation for the higher ORs observed for carcinoma in situ or early-stage cancer as compared with more invasive cancer.     

Intake of fruits, vegetables, and soy foods in relation to breast cancer risk in Korean women: a case-control study

We conducted a case-control study to examine the relationship between fruit, vegetable, and soy food intake and breast cancer risk in Korean women. Incident cases (n=359) were identified through cancer biopsies between March 1999 and August 2003 at two university hospitals in Seoul, Korea. Hospital-based controls (n=708) were selected from patients in the same hospitals during the same period. Subjects were asked by personal interview to indicate their average fruit, vegetable, and soy food intake for a 12-mo period 3 yr prior to the baseline phase. A food intake-frequency questionnaire (98 items) was given by a trained dietitian. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression after adjustment for confounding factors and total energy intake. There was no association between the intake of total fruits, vegetables, or soy food and breast cancer risk. Increasing consumption of grapes was linked to a significant protective effect against risk of breast cancer (OR=0.66; 95% CI=0.41-0.86; P<0.01). Among the vegetables, reduced risk was observed with high tomato intake (OR=0.62; 95% CI=0.38-0.81; P<0.01). Among soy foods, high consumption of cooked soybeans, including yellow and black soybeans, had an association with reduced breast cancer (OR=0.67; 95% CI=0.45-0.91; P<0.02). Our data suggest that increased intake of some fruits, vegetables, and soy foods may be associated with breast cancer risk reduction in Korean women.     

Adenocarcinoma of the stomach and esophagus and drinking water and dietary sources of nitrate and nitrite

We conducted a population-based case-control study of adenocarcinoma of the stomach and esophagus in Nebraska, U.S.A. Nitrate concentrations in public drinking water supplies were linked to residential water source histories. Among those using private wells at the time of the interview, we measured nitrate levels in water samples from wells. Dietary nitrate and nitrite were estimated from a food-frequency questionnaire. Among those who primarily used public water supplies (79 distal stomach, 84 esophagus, 321 controls), average nitrate levels were not associated with risk (highest versus lowest quartile: stomach OR=1.2, 95% CI [0.5-2.7]; esophagus OR=1.3, 95% CI [0.6-3.1]). We observed the highest ORs for distal stomach cancer among those with higher water nitrate ingestion and higher intake of processed meat compared with low intakes of both; however, the test for positive interaction was not significant (p=0.213). We did not observe this pattern for esophagus cancer. Increasing intake of nitrate and nitrite from animal sources was associated with elevated ORs for stomach cancer and with a significant positive trend in risk of esophagus cancer (P-trend=0.325 and 0.015, respectively). Larger studies with higher exposures to drinking water sources of nitrate are warranted to further evaluate N-nitroso compound precursors as risk factors for these cancers.     

Case-control analysis of dietary folate and risk of bladder cancer

Dietary folate, a water-soluble B vitamin found in a variety of fruits and vegetables, is of particular interest as a chemopreventive agent due to its role in DNA methylation and DNA synthesis and repair. We hypothesized that individuals with low folate intake would be at an increased risk for bladder cancer. Using an ongoing case-control study we assessed dietary folate in 409 incident bladder cancer patients and 451 healthy control subjects. A food-frequency questionnaire was used to estimate naturally occurring food folate (microg/kcal/day), dietary folate equivalents (DFE) from food sources (microg DFE/kcal/day), and DFE from all sources (microg DFE/kcal/day). Unconditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Bladder cancer patients reported a statistically significant lower intake of folate than control subjects for food folate and DFE from food sources (P < 0.001) but not for DFE from all sources (P = 0.061). In the highest quartile of food folate intake there was a 54% reduced risk for bladder cancer (OR = 0.46; 95% CI = 0.29-0.73) after adjusting for age, gender, ethnicity, smoking, and total energy intake. Similarly, the highest quartile of intake was associated with a 59% reduced risk for DFE from food sources (OR = 0.41; 95% CI = 0.26-0.65) and a 35% reduced risk for DFE from all sources (OR = 0.65; 95% CI = 0.42-1.00). In the joint-effects analyses using never smokers with high folate intake as the reference group (OR = 1.0), heavy smokers with low food folate intake had a 2.31-fold (95% CI = 1.11-4.82) increased risk, whereas heavy smokers with high folate intake had a reduced OR of 1.31 (95% CI = 0.53-3.26). Although the ORs were not statistically significant, light smokers and high folate intake exhibited a protective effect (OR = 0.62; 95% CI = 0.20-1.94), whereas an increased risk was observed for light smoking and low folate intake (OR = 1.41; 95% CI = 0.57-3.45). These patterns were consistent for the joint effects of smoking and DFE from food sources and DFE from all sources. In summary, high intake of dietary folate was associated with an overall decrease in bladder cancer risk. These data may have important implications for cancer prevention; however, large, hypothesis-driven, population-based clinical trials will be required to confirm these findings.     

Effects of Dietary Fiber,Fats, and Meat Intakes on the Risk of Barrett's Esophagus

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

Association of vegetable, fruit, and grain intakes with colorectal cancer: the Multiethnic Cohort Study

BACKGROUND: It is uncertain whether or not vegetables, fruit, or grains protect against colorectal cancer. OBJECTIVE: In a large prospective study, we investigated the association of vegetable, fruit, and grain intakes with colorectal cancer risk. DESIGN: Between 1993 and 1996, 85 903 men and 105 108 women completed a quantitative food-frequency questionnaire that included approximately 180 foods and beverages in the Multiethnic Cohort Study. A diagnosis of colorectal cancer was made in 1138 men and 972 women after an average follow-up of 7.3 y. Cox proportional hazards models were used to calculate multivariate-adjusted relative risks and 95% CIs for colorectal cancer. RESULTS: In men, multivariate adjustment for energy intake, dietary, and nondietary variables resulted in relative risks in the highest quintile group of 0.74 (95% CI: 0.59, 0.93; P for trend = 0.02) for vegetables and fruit combined, 0.80 (95% CI: 0.64, 0.99; P for trend = 0.09) for fruit alone, and 0.85 (95% CI: 0.69, 1.05; P for trend = 0.05) for vegetables alone. When colon and rectal cases were separated among men, the inverse associations were stronger for colon than for rectal cancer. In women, none of the associations with vegetables, fruit, or vegetables and fruit combined were significant. Grain intake was not associated with colorectal cancer for either men or women. CONCLUSION: The intake of vegetables and fruit was inversely related to colorectal cancer risk among men but not among women. The association appears stronger for colon than for rectal cancer.