Sources of folate and serum folate levels in older adults

This study examined dietary folate intake in 173 older adults. A subsample (n=128) also provided data about folic acid from vitamin/mineral supplements and serum folate. Subjects were community-dwelling men and women 60 years of age and older. Overall, this sample had healthful dietary patterns with adequate dietary folate. Mean dietary intake converted to dietary folate equivalents (DFE) was 464 microg DFE/day. However, 20% (n=36) had inadequate and 2% (n=3) had high dietary DFE (>1,000 microg DFE/day). A subsample (n=128) completed a dietary supplement questionnaire and biochemical assessment of folate. Adding folic acid from vitamin/mineral supplements to dietary folate (total DFE), intake increased to 766 microg DFE/day; 13% (n=16) had inadequate, 75% (n=95) had adequate, and 13% (n=13) had high total DFE. No subject with low total DFE reported supplement use, but 94% (n=39) with high total DFE intake did so. In the subsample, all subjects had acceptable serum folate levels (mean serum folate=28.0+/-13.8 ng/mL [63.5+/-31.3 nmol/L]). In conclusion, vitamin/mineral supplements should be included in nutrition assessment of older adults. Older adults may be at risk for inadequate folate intake if their energy intake is low, they do not take a vitamin/mineral supplement, or are not consuming fortified cereals. However, older adults may be at risk for excess folic acid intake if they consume both a supplement and fortified cereals.     

Dietary intakes of selected nutrients and food groups and risk of cervical cancer

We investigated the relationships between intakes of selected dietary nutrients and food groups and risk of cervical cancer in a hospital-based, case-control study including 239 cases diagnosed with squamous cell carcinoma of the cervix and 979 hospital patients with nonneoplastic diagnoses who completed a self-administered questionnaire between 1982 and 1998 at Roswell Park Cancer Institute. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression adjusting for age, education, smoking status, use of oral contraceptives, barrier contraceptives and spermicides, family history of cervical cancer, year questionnaire completed, and energy intake. Significant reductions in risk of approximately 40-60% were observed for women in the highest vs. lowest tertiles of dietary fiber (OR=0.59, 95% CI=0.37-0.94), vitamin C (OR=0.52, 95% CI=0.33-0.80), vitamin E (OR=0.44, 95% CI=0.27-0.72), vitamin A (OR=0.47, 95% CI=0.30-0.73), alpha-carotene (OR=0.41, 95% CI=0.27-0.63), beta-carotene (OR=0.44, 95% CI=0.29-0.68), lutein (OR=0.51, 95% CI=0.33-0.79), folate (OR=0.55, 95% CI=0.34-0.88), and total fruit and vegetable intake (OR=0.52, 95% CI=0.34-0.77). Our findings suggest that a diet rich in plant-based nutrients may be important in reducing the risk of cervical cancer.     

Dietary Intakes of Selected Nutrients and Food Groups and Risk of Cervical Cancer

We investigated the relationships between intakes of selected dietary nutrients and food groups and risk of cervical cancer in a hospital-based, case-control study including 239 cases diagnosed with squamous cell carcinoma of the cervix and 979 hospital patients with nonneoplastic diagnoses who completed a self-administered questionnaire between 1982 and 1998 at Roswell Park Cancer Institute. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression adjusting for age, education, smoking status, use of oral contraceptives, barrier contraceptives and spermicides, family history of cervical cancer, year questionnaire completed, and energy intake. Significant reductions in risk of approximately 40–60% were observed for women in the highest vs. lowest tertiles of dietary fiber (OR = 0.59, 95% CI = 0.37–0.94), vitamin C (OR = 0.52, 95% CI = 0.33–0.80), vitamin E (OR = 0.44, 95% CI = 0.27–0.72), vitamin A (OR = 0.47, 95% CI = 0.30–0.73), α -carotene (OR = 0.41, 95% CI = 0.27–0.63), β -carotene (OR = 0.44, 95% CI = 0.29–0.68), lutein (OR = 0.51, 95% CI = 0.33–0.79), folate (OR = 0.55, 95% CI = 0.34–0.88), and total fruit and vegetable intake (OR = 0.52, 95% CI = 0.34–0.77). Our findings suggest that a diet rich in plant-based nutrients may be important in reducing the risk of cervical cancer.     

Folate intake, serum homocysteine and methylenetetrahydrofolate reductase (MTHFR) C677T genotype are not associated with oral cancer risk in Puerto Rico

We examined the relationships between folate and methionine intake, serum homocysteine levels (as a biomarker for folate metabolism), and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism genotype and risk of oral cancer in a population-based, case-control study in Puerto Rico. Structured questionnaires were used to collect information on demographic factors, usual adult diet, and tobacco and alcohol use. Oral epithelial cells and blood samples were collected from a subset of subjects. Analyses were conducted by logistic regression, adjusting for age, sex, lifetime smoking and lifetime alcohol intake, with the following numbers of cases/controls, respectively: dietary data (341/521); MTHFR genotype (148/149); and homocysteine (60/90). Although increased folate intake was associated with decreased oral cancer risk [adjusted odds ratio (OR) in highest vs. lowest quartile = 0.6, 95% confidence interval (CI): 0.4, 1.0, P(trend) = 0.05)], this finding was due almost entirely to folate intake from fruit (adjusted OR = 0.4, 95% CI: 0.2, 0.6; P(trend) = 0.0001), whereas other dietary folate sources showed no clear association. Methionine intake and serum homocysteine levels were not associated with oral cancer risk. Subjects with the MTHFR C677T homozygous variant (TT) genotype had a nonsignificantly lower risk, and risk patterns tended to differ by level of folate, methionine, alcohol intake and smoking, although the power to detect significant associations in subgroups of these variables was low. Risks for oral cancer are not folate specific; preventive recommendations for this disease should emphasize the importance of a healthy diet, including substantial intake of fruits.     

Dietary carotenoids and genetic instability modify bladder cancer risk

In vitro and in vivo studies have shown that carotenoid supplementation is associated with decreased DNA damage, but the role of dietary carotenoids in cancer risk remains controversial because epidemiologic studies have yielded conflicting results. Limited data exist regarding the role of dietary carotenoids in the context of constitutional genetic instability in cancer risk. This case-control study estimated dietary carotenoid intake [microg/(kJ . d)] from a FFQ for 423 patients with bladder cancer and 467 healthy controls, and quantified baseline and benzo[a]pyrene diol epoxide (BPDE)- and gamma-radiation-induced DNA damage in the peripheral blood lymphocytes using the comet assay. Overall, intake of total carotenoids was lower (P < 0.01) for bladder cancer cases (mean +/- SD: 1273.4 +/- 688.9) compared with healthy controls (1501.3 +/- 791.5). When categorized into quartiles, there was an inverse association between increasing levels of carotenoid intake and bladder cancer risk with greatest protective effect [odds ratio (OR) = 0.56, 95% CI, 0.37-0.85] in the quartile with the highest level of intake. Baseline and mutagen-induced DNA damage was significantly higher in cases than in controls; when analyzed jointly with carotenoid intake, high DNA damage and low carotenoid intake were associated with the highest risk. For example, with high baseline DNA damage and low total carotenoid intake, the OR was 3.08 (95% CI, 1.64-5.77); with high baseline DNA damage and high total carotenoid intake, the risk was somewhat attenuated (OR = 2.49, 95% CI, 1.28-4.84). The risk was decreased further for low baseline DNA damage and low total carotenoid intake (OR = 2.18; 95% CI, 1.13-4.22). This study provides evidence of a preventive role for carotenoids in bladder cancer, and these data may have important implications for cancer prevention, especially for individuals susceptible to DNA damage.     

Dietary intake of lycopene is associated with reduced pancreatic cancer risk

Although fruits and vegetables have been implicated in the etiology of pancreatic cancer, the role of phytochemicals in these food groups has received little attention to date. In this study, we investigated the possible association between dietary carotenoids and pancreatic cancer risk. A case-control study of 462 histologically confirmed pancreatic cancer cases and 4721 population-based controls in 8 Canadian provinces took place between 1994 and 1997. Dietary intake was assessed by a self-administered FFQ. Unconditional logistic regression was used to assess associations between specific and total carotenoid intakes and the risk of pancreatic cancer. All tests of statistical significance were 2-sided. After adjustment for age, province, BMI, smoking, educational attainment, dietary folate, and total energy intake, lycopene, provided mainly by tomatoes, was associated with a 31% reduction in pancreatic cancer risk among men [odds ratio (OR) = 0.69; 95% CI: 0.46-0.96; P = 0.026 for trend] when comparing the highest and lowest quartiles of intake. Both beta-carotene (OR = 0.57; 95% CI: 0.32-0.99; P = 0.016 for trend) and total carotenoids (OR = 0.58; 95% CI: 0.34-1.00; P = 0.02 for trend) were associated with a significantly reduced risk among those who never smoked. The results of this study suggest that a diet rich in tomatoes and tomato-based products with high lycopene content may help reduce pancreatic cancer risk.     

天津市区胃癌危险因素的配对病例对照研究

目的 进一步探讨各危险因素与胃癌的关系。方法 选取天津市市内六区1998年和1999年的189例新发胃癌病人并按性别、年龄、民族等配比条件选取该市189名健康人群进行1：1配对的病例对照研究,资料处理采用条件logistic回归分析。结果 多因素条件logistic回归分析显示胃癌的发病与下列4种因素关节密切：烟熏食品OR=2.34,95%CI：1.60-4.98;吸烟量OR=6.07,95%CI：1.26-7.16;喜食重盐饮食OR=1.95,95%CI：1.27-3.23;过量摄入动物肉类OR=1.46,95%CI：1.05-2.02。结论 经常食用烟熏食品、吸烟量大、喜食重盐饮食、过量摄入动物肉类可能是胃癌的危险因素。     

Tea as a Potential Chemopreventive Agent in PhIP Carcinogenesis: Effects of Green Tea and Black Tea on PhIP-DNA Adduct Formation in Female F-344 Rats

Disturbances in DNA methylation have been hypothesized as being involved in carcinogenesis. It has been proposed that dietary factors such as folate, alcohol, and methionine may be associated with colon cancer because of their involvement in DNA methylation processes. Data from a large retrospective population‐based case‐control study of incident colon cancer were used to evaluate whether intake of alcohol and other dietary factors involved in DNA methylation are associated with colon cancer. Dietary data were obtained using a detailed diet history questionnaire. We did not observe strong independent associations between folate, vitamin B6, vitamin B12, methionine, or alcohol and risk of colon cancer after adjusting for body size, physical activity, cigarette smoking patterns, energy intake, and dietary intake of fiber and calcium. However, when assessing the associations between colon cancer and a composite dietary profile based on alcohol intake, methionine, folate, vitamin B12, and vitamin B6 we observed a trend of increasing risk as one moved from a low‐ to a high‐risk group. This trend was modest and most marked in those diagnosed at a younger age [odds ratio (OR) for men = 1.3, 95% confidence interval (CI) = 0.9–1.9; OR for women = 1.6, 95% CI= 1.0–2.6]. We observed that associations with this high‐risk dietary profile were greater among those who took aspirin or nonsteroidal anti‐inflammatory drugs on a regular basis and were younger at the time of diagnosis (men OR = 1.7, 95% CI = 1.0–3.2; women OR = 2.2, 95% CI= 1.0–4.8) and for distal tumors (men OR = 1.4, 95% CI = 0.9–2.3; women OR = 2.0, 95% CI = 1.0–3.8). Findings from this study provide only limited support for previously reported associations between dietary factors involved in DNA methylation and risk of colon cancer.     

Dietary vitamin D and calcium intake and premenopausal breast cancer risk in a German case-control study

Epidemiological studies and laboratory data suggest that vitamin D may protect against the development of cancer, including breast cancer. Vitamin D supply affects the bioavailability of dietary calcium, which might also have anticarcinogenic effects. However, few studies considered them jointly. We used a population-based case-control study in Germany to examine the independent and joint effects of dietary vitamin D and calcium on premenopausal breast cancer risk. Dietary information was assessed using a validated food frequency questionnaire from 278 premenopausal cases and 666 age-matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate models adjusting vitamin D models for calcium intake and vice versa. Breast cancer risk was significantly inversely associated with vitamin D intake. The OR and 95% CI for the highest intake category (> or = 5 microg/day) was 0.50 (95% CI = 0.26-0.96) compared with the lowest (< 2 microg/day; P(trend) = 0.02). Dietary calcium intake was not associated with breast cancer (OR = 0.73, 95% CI = 0.41-1.29) for the highest (> or = 1,300 mg/day) versus the lowest category (< 700 mg/day), P(trend) = 0.29). No statistically significant interaction between the 2 nutrients was observed. Our data support a protective effect of dietary vitamin D on premenopausal breast cancer risk independent of dietary calcium intake.     

Intake of folate and related nutrients in relation to risk of epithelial ovarian cancer

Assessments of the relation between folate intake and ovarian cancer risk have been limited and inconsistent. Therefore, the authors prospectively examined the association of dietary and supplemental intakes of folate, methionine, and vitamin B(6) with ovarian cancer risk among 80,254 Nurses' Health Study participants. Beginning in 1976, women completed biennial questionnaires assessing ovarian cancer risk factors; starting in 1980, food frequency questionnaires were administered every 2-4 years. During 22 years of follow-up (1980-2002), the authors confirmed 481 incident epithelial ovarian cancers. There were no associations between total folate (top quintile vs. bottom: relative risk (RR) = 1.21, 95% confidence interval (CI): 0.92, 1.60), methionine (RR = 1.00, 95% CI: 0.76, 1.33), dietary vitamin B(6) (RR = 1.09, 95% CI: 0.81, 1.47), or total vitamin B(6) (RR = 1.13, 95% CI: 0.85, 1.51) intake and ovarian cancer risk. Higher dietary folate was associated with a modestly decreased risk after exclusion of cases diagnosed during the 4 follow-up years after dietary assessment (RR = 0.66, 95% CI: 0.43, 1.03) and for the serous subtype (RR = 0.51, 95% CI: 0.31, 0.84). Results did not vary by alcohol intake, multivitamin use, menopausal status, or oral contraceptive use. There was little evidence that folate, methionine, and vitamin B(6) are important in ovarian cancer risk, although dietary folate was inversely associated with risk in some analyses.     

Nutritional factors and susceptibility to arsenic-caused skin lesions in West Bengal, India

There has been widespread speculation about whether nutritional deficiencies increase the susceptibility to arsenic health effects. This is the first study to investigate whether dietary micronutrient and macronutrient intake modulates the well-established human risk of arsenic-induced skin lesions, including alterations in skin pigmentation and keratoses. The study was conducted in West Bengal, India, which along with Bangladesh constitutes the largest population in the world exposed to arsenic from drinking water. In this case-control study design, cases were patients with arsenic-induced skin lesions and had < 500 microg/L arsenic in their drinking water. For each case, an age- and sex-matched control was selected from participants of a 1995-1996 cross-sectional survey, whose drinking water at that time also contained < 500 microg/L arsenic. Nutritional assessment was based on a 24-hr recall for major dietary constituents and a 1-week recall for less common constituents. Modest increases in risk were related to being in the lowest quintiles of intake of animal protein [odds ratio (OR) = 1.94; 95% confidence interval (CI), 1.05-3.59], calcium (OR = 1.89; 95% CI, 1.04-3.43), fiber (OR = 2.20; 95% CI, 1.15-4.21), and folate (OR = 1.67; 95% CI, 0.87-3.2). Conditional logistic regression suggested that the strongest associations were with low calcium, low animal protein, low folate, and low fiber intake. Nutrient intake was not related to arsenic exposure. We conclude that low intake of calcium, animal protein, folate, and fiber may increase susceptibility to arsenic-caused skin lesions. However, in light of the small magnitude of increased risks related to these dietary deficiencies, prevention should focus on reducing exposure to arsenic.     

叶酸与宫颈癌关系的病例对照研究

目的探讨膳食叶酸、血清叶酸与宫颈癌的关系以及叶酸和人乳头瘤病毒(HPV)16在宫颈癌发生中的相互作用。方法采用以医院为基础的病例对照研究方法,对111例经病理学确诊的宫颈鳞癌新发病例和111例子宫肌瘤患者进行年龄、籍贯、居住地匹配,在收集宫颈癌相关因素的同时,采用食物频数问卷(FFQ)调查膳食叶酸摄入情况,利用特异PCR检测HPV16 DNA,血清叶酸采用RIA定量测定。结果官颈癌组HPV16感染率(61．26％)显著高于对照组(28．83％),调整OR 值4．95(95％CI:2．49-9．83);病例组膳食叶酸摄入量(5．00μg/kcal±0．41 μg／kcal)和血清叶酸水平 (1．79 ng／ml±1．42 ng／ml)均低于对照组(5．14μg／kcal±0．35μg/kcal,2．59 ng／ml±2．81 ng／ml),差异有统计学意义,特别是随着血清叶酸水平的降低,患宫颈癌的危险性增加(X2=17．37,P=0．000);血清叶酸水平较低同时伴有HPV16感染患宫颈癌的危险明显高于两者单独作用之和,交互作用检验有统计学意义(G=5．56,P=0．02)。结论叶酸缺乏可增加宫颈癌发生的危险。     

Risk factors for urothelial carcinoma: drinking measures, smoking and other life style-related risk factors--results of the Berlin Urothelial Study (BUS)

With the exception of smoking and several occupational exposures there is little knowledge about risk factors for urothelial cancer. A case control study in the area of former West Berlin was performed from 1990-1995 to investigate the role of several lifestyle risk factors, such as smoking, drinking behaviour and regular intake of analgesics and laxatives. The study includes 647 hospital-based incident cases with bladder cancer (n = 571), renal pelvis cancer (n = 51), and ureter cancer (n = 25), and 647 population-based controls which were matched individually by sex and age. Data analyses were carried out using standard methods for case control studies (conditional multiple logistic regression analysis). Odds ratios (OR) and 95% confidence intervals (CI) were applied as effect parameter. Statistically significantly increased odds ratios were observed for current smoking (OR: 3.46, 95% CI: 2.50-4.78), previous but now abandoned smoking (OR: 1.51, 95% CI: 1.09-2.81), and for regular intake of laxatives (OR: 2.52, 95% CI: 1.56-4.09). Furthermore, an increased risk for urothelial cancer was observed for daily consumption of three and more litres of cold drinks (OR: 2.65 95% CI: 1.12-6.24). The results underline that lifestyle factors other than smoking may contribute to a higher risk of urothelial cancer.     

Dietary acrylamide intake and the risk of renal cell, bladder, and prostate cancer

BACKGROUND: Acrylamide, a probable human carcinogen, was recently detected in various heat-treated carbohydrate-rich foods. Epidemiologic studies on the relation with cancer have been few and largely negative. OBJECTIVE: We aimed to prospectively examine the association between dietary acrylamide intake and renal cell, bladder, and prostate cancers. DESIGN: The Netherlands Cohort Study on diet and cancer includes 120,852 men and women aged 55-69 y. At baseline (1986), a random subcohort of 5000 participants was selected for a case-cohort analysis approach using Cox proportional hazards analysis. Acrylamide intake was assessed with a food-frequency questionnaire at baseline and was based on chemical analysis of all relevant Dutch foods. RESULTS: After 13.3 y of follow-up, 339, 1210, and 2246 cases of renal cell, bladder, and prostate cancer, respectively, were available for analysis. Compared with the lowest quintile of acrylamide intake (mean intake: 9.5 microg/d), multivariable-adjusted hazard rates for renal cell, bladder, and prostate cancer in the highest quintile (mean intake: 40.8 microg/d) were 1.59 (95% CI: 1.09, 2.30; P for trend = 0.04), 0.91 (95% CI: 0.73, 1.15; P for trend = 0.60), and 1.06 (95% CI: 0.87, 1.30; P for trend = 0.69), respectively. There was an inverse nonsignificant trend for advanced prostate cancer in never smokers. CONCLUSIONS: We found some indications for a positive association between dietary acrylamide and renal cell cancer risk. There were no positive associations with bladder and prostate cancer risk.     

A long-term controlled folate feeding study in young women supports the validity of the 1.7 multiplier in the dietary folate equivalency equation

The presence of folic acid in enriched cereal grain products and the higher bioavailability of folic acid than food folate led to the expression of the 1998 folate RDA, 400 microg/d, as dietary folate equivalents (DFE). DFE are defined as: mug natural food folate + 1.7 x microg synthetic folic acid. The 1.7 multiplier was based on assumptions that added folic acid was 85% available and food folate was 50% available. The 85/50 ratio also inferred that the bioavailability of food folate was approximately 60% relative to added folic acid. The objective of this long-term controlled feeding study was to assess the dietary folate equivalency of folic acid. After a 2-wk period of folate restriction, women (n = 42, 18-45 y old) consumed either 400 or 800 microg DFE/d derived from various combinations of food folate and folic acid for 12 wk. Folic acid was converted to DFE using the 1.7 multiplier from the DFE calculation and was consumed with a meal throughout the treatment period. Folate status response to the various treatments was assessed during wk 12-14. Serum folate, RBC folate, and plasma total homocysteine did not differ among the 400 microg DFE/d groups or among the 800 microg DFE/d groups. In contrast, consumption of 800 microg DFE/d led to higher (P 相似文献   

Dietary intake of soy protein and tofu in association with breast cancer risk based on a case-control study

Soy food and its constituents may protect against breast cancer, but the association between soy intake and decreased breast cancer risk is inconsistent. We evaluated the relationship between breast cancer risk and the dietary intake of soy protein as measured by total soy food and tofu intake. Histologically confirmed cases (n = 362) were matched to controls by age (within 2 yr) and menopausal status. High soy protein intake was associated with reduced breast cancer risk in analyses adjusted for potential confounders including dietary factors among premenopausal women (odds ratio [OR] = 0.39 in the highest quintile, 95% confidence interval [CI] = 0.22-0.93, P for trend = 0.03) and postmenopausal women (OR = 0.22, 95% CI = 0.06-0.88, P for trend = 0.16). We also found an inverse association between total tofu intake and breast cancer risk among premenopausal women (for total tofu intake, OR = 0.23 in the highest quintile, 95% CI = 0.11-0.48, P for trend < 0.01; for at least 1 serving of tofu as the main ingredient per day, OR = 0.26, 95% CI = 0.13-0.55, P for trend < 0.01). We concluded that increased regular soy food intake at a level equivalent to traditional Korean consumption levels may be associated with a reduced risk of breast cancer, and this effect is more pronounced in premenopausal women.     

Dietary and other methyl-group availability factors and pancreatic cancer risk in a cohort of male smokers

The authors examined prospectively whether dietary folate and other factors known to influence methyl-group availability were associated with the development of exocrine pancreatic cancer within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. Of the 27,101 healthy male smokers aged 50--69 years who completed a self-administered dietary questionnaire at baseline, 157 developed pancreatic cancer during up to 13 years of follow-up from 1985 to 1997. Cox proportional hazards models were used to estimate the hazards ratios and 95% confidence intervals. The adjusted hazards ratio comparing the highest with the lowest quintile of dietary folate intake was 0.52 (95% confidence interval: 0.31, 0.87; p-trend = 0.05). Dietary methionine, alcohol intake, and smoking history did not modify this relation. No significant associations were observed between dietary methionine, vitamins B(6) and B(12), or alcohol intake and pancreatic cancer risk. Consistent with prior studies, this study shows that cigarette smoking was associated with an increased risk (highest compared with lowest quintile, cigarettes per day: hazards ratio = 1.82; 95% confidence interval: 1.10, 3.03; p-trend = 0.05). These results support the hypothesis that dietary folate intake is inversely associated with the risk of pancreatic cancer and confirm the risk associated with greater cigarette smoking.     

Cigarette smoking and risk of bladder, pancreas, kidney, and colorectal cancers in Iowa

PURPOSE: Although there are numerous reports on the effects of cigarette smoking and cancer, they have infrequently compared risks at more than one cancer site after multivariate adjustment. We analyzed data from a population-based case-control study that included five anatomic sites to evaluate the association between cigarette smoking and each cancer site and to rank the associations by site. METHODS: Study respondents included 1452 bladder, 406 kidney, 376 pancreatic, 685 colon, and 655 rectal cancer cases, as well as 2434 population controls. A self-administered questionnaire was used to collect information on cigarette smoking and other potential confounders including occupation, drinking water source, and dietary practices. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), after adjustment for age, total energy intake, and other site- and sex-specific confounders. RESULTS: In both sexes, cigarette smoking (ever vs. never) was associated with risk of bladder cancer (OR = 2.5; 95% CI, 2.0-3.1 for males; OR = 2.7; 2.0-3.6 for females) and pancreatic cancer (OR = 1.8; 1.2-2.8 for males; OR = 2.1; 1.4-3.1 for females). Cigarette smoking also increased the risk of kidney cancer among males (OR = 1.8; 1.3-2.7), and to a lesser degree, among females (OR = 1.2; 0.8-1.8). No association was found for colon or rectal cancer in either sex. CONCLUSIONS: Cigarette smoking increased the risk of bladder, kidney, and pancreatic cancer in men and women. The rankings of multivariate-adjusted ORs from highest to lowest were bladder, pancreas, kidney, and colorectum, with little difference between men and women.     

Dietary folate intake, alcohol, and risk of breast cancer in a prospective study of postmenopausal women.

Low B-vitamin intake may increase risk of breast cancer through decreased DNA repair capacity. Alcohol intake increases risk for breast cancer, with evidence from prospective studies of an interaction between alcohol and folate. We explored dietary intake of folate and other B vitamins with risk of breast cancer in a cohort study of 34,387 postmenopausal women. To measure diet, we mailed a food frequency questionnaire; we estimated nutrient intakes and categorized them into four levels: <10th, 11th-30th, 31st-50th, and >50th percentiles. Through 12 years of follow-up, we identified 1,586 cases of breast cancer in the cohort at risk. We estimated relative risks (RRs) and 95% confidence intervals (CIs) through Cox regression models adjusted for age, energy, and other risk factors. Women in the lowest 10th percentile of folate intake from diet alone were at modestly increased risk of breast cancer relative to those above the 50th percentile: RR = 1.21 (95% CI = 0.91--1.61). We examined the joint association of folate intake and alcohol use on risk of breast cancer, with the reference group defined as women with high folate (>50th percentile) and no alcohol use. The RRs of breast cancer associated with low dietary folate intake were 1.08 (95% CI = 0.78--1.49) among nondrinkers, 1.33 (95% CI = 0.86--2.05) among drinkers of < or = 4 gm per day, and 1.59 (95% CI = 1.05--2.41) among drinkers of > 4 gm per day. These results suggest that the risks of postmenopausal breast cancer may be increased among women with low intakes of folate if they consume alcohol-containing beverages.