The association between dietary lignans, phytoestrogen-rich foods, and fiber intake and postmenopausal breast cancer risk: a German case-control study

Phytoestrogens are structurally similar to estrogens and may affect breast cancer risk by mimicking estrogenic/antiestrogenic properties. In Western societies, whole grains and possibly soy foods are rich sources of phytoestrogens. A population-based case-control study in German postmenopausal women was used to evaluate the association of phytoestrogen-rich foods and dietary lignans with breast cancer risk. Dietary data were collected from 2,884 cases and 5,509 controls using a validated food-frequency questionnaire, which included additional questions phytoestrogen-rich foods. Associations were assessed using conditional logistic regression. All analyses were adjusted for relevant risk and confounding factors. Polytomous logistic regression analysis was performed to evaluate the associations by estrogen receptor (ER) status. High and low consumption of soybeans as well as of sunflower and pumpkin seeds were associated with significantly reduced breast cancer risk compared to no consumption (OR = 0.83, 95% CI = 0.70-0.97; and OR = 0.66, 95% CI = 0.77-0.97, respectively). The observed associations were not differential by ER status. No statistically significant associations were found for dietary intake of plant lignans, fiber, or the calculated enterolignans. Our results provide evidence for a reduced postmenopausal breast cancer risk associated with increased consumption of sunflower and pumpkin seeds and soybeans.     

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.     

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.     

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.     

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.     

Genetic variation in myeloperoxidase modifies the association of serum α-tocopherol with aggressive prostate cancer among current smokers

We investigated associations of serum α- and γ-tocopherols and their effect modification by polymorphisms in oxidative stress regulatory enzymes in relation to prostate cancer risk. In a nested case-control study in the Carotene and Retinol Efficacy Trial, prerandomized serum α- and γ-tocopherol were assayed among 684 men with incident prostate cancer [375 nonaggressive and 284 aggressive cancer (stage III/IV or Gleason score ≥7)] and 1441 controls. Manganese superoxide dismutase Ala-16Val (rs4880), glutathione peroxidase 1 Pro200Leu (rs1050450), catalase -262 C > T (rs1001179), and myeloperoxidase (MPO) G-463A (rs2333227) were genotyped. A multivariate-adjusted inverse association of serum α-tocopherol with total prostate cancer risk was observed in current smokers (OR = 0.62, 95% CI = 0.40-0.96, 4th vs. 1st quartiles). High (≥median) compared to low serum concentrations of α- and γ-tocopherol were inversely associated with aggressive prostate cancer in current smokers (OR = 0.50, 95% CI = 0.32-0.78 and OR = 0.64, 95% CI = 0.43-0.95, respectively). The association was stronger among those with MPO G/A+A/A genotypes. Among current smokers with low serum α-tocopherol concentrations, MPO G/A+A/A, the genotypes downregulating oxidative stress, were associated with an increased risk for aggressive prostate cancer (OR = 2.06, 95% CI = 1.22-3.46). Conversely, current smokers with these genotypes who had high α-tocopherol concentrations had a reduced risk for aggressive prostate cancer (OR = 0.34, 95% CI = 0.15-0.80; P-interaction = 0.001). In conclusion, among current smokers, both high serum α- and γ-tocopherol concentrations were associated with reduced risks of aggressive prostate cancer. The α-tocopherol-associated risks are modified by polymorphism in MPO G-463A.     

Soy Food Consumption and Lung Cancer Risk: A Meta-Analysis Using a Common Measure Across Studies

A published meta-analysis pooled individual studies by using the study-specific odds ratio (OR) or relative risk (RR) for the highest vs. lowest category of soy or isoflavone intake from each study, but it should be problematic to make comparison between studies/populations for lung cancer risk as the quantiles are so different from different studies/populations. Therefore, we conducted a meta-analysis to explore the association between exposure of estimated daily soy protein intake in grams and lung cancer risk. We extracted ORs or RRs and 95% confidence intervals (CIs), converted them to the estimated ones for daily soy protein intake and pooled them using fixed or random effects models from 11 epidemiologic studies. Overall, the inverse association between daily grams of soy protein intake and risk of lung cancer was borderline statistically significant (OR = 0.98, 95% CI = 0.96 to 1.00); the inverse association was statistically significant in nonsmokers (OR = 0.96; 95% CI = 0.93 to 0.99) and stronger than in smokers (P for difference <0.05). No statistical significance for the associations was observed between genders, the origin of the participants, study design and types of soy intake. This study suggests a borderline reduction in risk of lung cancer with daily soy protein intake in grams, and a significant inverse association in nonsmokers.     

(n-6) PUFA increase and dairy foods decrease prostate cancer risk in heavy smokers

Previous studies offer suggestive, but not definitive, evidence that total fat or specific fats may increase prostate cancer risk. This study investigates associations of dietary fat, meat, and dairy foods with prostate cancer risk among 12,025 men in the Carotene and Retinol Efficacy Trial (CARET). After 11 y of follow-up, 890 incident prostate cancers were reported and confirmed. Diet was assessed by a biannual FFQ. Cox proportional hazards models were used to estimate multivariate-adjusted hazard ratios (HR) of intake of fat and fat-related foods (meat and dairy) with prostate cancer incidence. Multiplicative interaction terms tested whether associations differed by family history, race, or smoking. Overall, fat was not associated with total, nonaggressive or aggressive prostate cancer. In subgroup analyses the HR for men with a family history of prostate cancer were 2.47 (95%CI = 0.96-6.37) and 2.61 (95% CI = 1.01-6.72) for total polyunsaturated fat (PUFA) and (n-6) PUFA for the 4th vs. 1st quartiles of intake, respectively. Red meat was not associated with total or aggressive prostate cancer. However, higher dairy intake had a statistically significant reduced risk of aggressive prostate cancer than lower dairy intake (HR = 0.59, 95% CI = 0.40-0.85). Dairy foods also protected current, but not former, smokers against aggressive cancer (HR = 0.42, 95% CI = 0.25-0.70). Our findings suggest that associations of dietary fat with prostate cancer risk may vary by type of fat or fat-containing food, and that risk may vary by host factors, including family history and smoking.     

Soy Food Intake Associated with Obesity and Hypertension in Children and Adolescents in Guangzhou,Southern China

The associations between soy food intake and cardio-metabolic risk factors in children remain unclear due to limited evidence. We aim to explore soy food intake and its association with the risks of obesity and hypertension in Chinese children and adolescents. A total of 10,536 children and adolescents aged 7–18 years (5125 boys and 5411 girls) were enrolled in a cross-sectional study in Guangzhou City, southern China. Data on demographic characteristics and dietary consumption were collected using self-reported questionnaires, and anthropometric characteristics were measured. Obesity, abdominal obesity, and hypertension were defined using Chinese criteria for children and adolescents. A multiple logistic regression model was applied to estimate the association between soy food intake and obesity and hypertension. Roughly 39.5% of the participants consumed soy food more than three times per week. The mean amounts of liquid and solid soy food intake were 0.35 ± 0.54 cups/day and 0.46 ± 0.63 servings/day, respectively. The adjusted odds ratios (OR) of hypertension among those with high liquid soy food intake and a high frequency of all soy food intake (more than three times/week) were 0.79 (95% confidence interval (CI), 0.67–0.94), and 0.83 (95% CI, 0.70–0.97) compared to those with no intake. Additionally, the adjusted OR of obesity among those with high solid soy food intake and a high frequency of all soy food intake were 1.34 (95% CI, 1.09–1.63) and 1.30 (95% CI, 1.07–1.58), respectively. In conclusion, 39.5% of southern Chinese children and adolescents had high soy food intake (more than three times/week), which was significantly associated with a lower prevalence of hypertension and a greater prevalence of obesity.     

Soy Food Consumption and Risk of Prostate Cancer: A Meta-Analysis of Observational Studies

Soybean products have been suggested to have a chemo preventive effect against prostate cancer. The aim of this study was to provide a comprehensive meta-analysis on the extent of the possible association between soy-based food consumption and the risk of prostate cancer. Five cohort studies and 8 case-control studies were identified using MEDLINE, EMBASE, CINAHL, Korea Medical Database, KoreaMed, Korean studies Information Service System, Japana Centra Revuo Medicina, China National Knowledge Infrastructure, and a manual search. Summary odds ratios (ORs) comparing high versus low categories of soybean consumptions were calculated on the basis of the random effect model. We analyzed the associations based on the different types of soybean consumptions. The summary ORs (95% CI) for total soy foods were 0.69 (CI = 0.57–0.84) and 0.75 (CI = 0.62–0.89) for nonfermented soy foods. Among individual soy foods, only tofu yielded a significant value of 0.73 (CI = 0.57–0.92). Consumption of soybean milk, miso, or natto did not significantly reduce the risk of prostate cancer. Genistein and daidzein were associated with a lower risk of prostate cancer. This systematic review suggests that soy food consumption could lower the risk of prostate cancer. This conclusion, however, should be interpreted with caution because various biases can affect the results of a meta-analysis.     

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.     

Fruits, vegetables, soy foods and breast cancer in pre- and postmenopausal Korean women: a case-control study

We carried out a case-control study to examine the relationship between fruits, vegetables, and soy foods intake with breast cancer risk in Korean women. Incident cases (n = 359) were identified through cancer biopsies and hospital-based controls (n = 708) were selected in the same hospitals. Subjects were asked to indicate usual dietary habits, which were assessed using a semi-quantitative food frequency questionnaire (98 items). Odds ratio (OR) and 95% confidence intervals (95% CI) were calculated by unconditional logistic regression after adjustment for additional confounding factors according to the menopausal status. High grape intake showed an inverse association of breast cancer in postmenopausal women (OR = 0.59, 95% CI = 0.35-0.95; p for trend = 0.05). High tomato intake was associated with reduced breast cancer risk in premenopausal women (OR = 0.59, 95% CI = 0.38-0.89, p for trend = 0.04). In postmenopausal women, green pepper intake showed an inverse association of breast cancer risk (OR = 0.60, 95% CI = 0.43-0.96, p for trend = 0.03). High soybean intake showed an inverse association of breast cancer in postmenopausal women (OR = 0.61, 95% CI = 0.34-0.89, p for trend = 0.02). Our study suggests that high intake of some fruits, vegetables, and soybeans may be associated with a reduced breast cancer risk.     

Serum selenium and risk of prostate cancer-a nested case-control study

BACKGROUND: Selenium is a potential chemopreventive agent against prostate cancer, whose chemoprotective effects are possibly mediated through the antioxidative properties of selenoenzymes. Interrelations with other antioxidative agents and oxidative stressors, such as smoking, are poorly understood. OBJECTIVES: The aims were to investigate the association between serum selenium and prostate cancer risk and to examine interactions with other antioxidants and tobacco use. DESIGN: A nested case-control study was performed within the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Serum selenium in prospectively collected samples was compared between 724 incident prostate cancer case subjects and 879 control subjects, frequency-matched for age, time since initial screen, and year of blood draw. The men were followed for up to 8 y. RESULTS: Overall, serum selenium was not associated with prostate cancer risk (P for trend = 0.70); however, higher serum selenium was associated with lower risks in men reporting a high (more than the median: 28.0 IU/d) vitamin E intake [odds ratio (OR) for the highest compared with the lowest quartile of selenium: 0.58; 95% CI: 0.37, 0.91; P for trend = 0.05; P for interaction = 0.01] and in multivitamin users (OR for highest compared with the lowest quartile of selenium: 0.61; 95% CI: 0.36, 1.04; P for trend = 0.06; P for interaction = 0.05). Furthermore, among smokers, high serum selenium concentrations were related to reduced prostate cancer risk (OR for the highest compared with the lowest quartile of selenium: 0.65; 95% CI: 0.44, 0.97; P for trend = 0.09; P for interaction = 0.007). CONCLUSION: Greater prediagnostic serum selenium concentrations were not associated with prostate cancer risk in this large cohort, although greater concentrations were associated with reduced prostate cancer risks in men who reported a high intake of vitamin E, in multivitamin users, and in smokers.     

Serum phospholipid fatty acids and prostate cancer risk: results from the prostate cancer prevention trial

Inflammation may be involved in prostate cancer development and progression. This study examined the associations between inflammation-related phospholipid fatty acids and the 7-year-period prevalence of prostate cancer in a nested case-control analysis of participants, aged 55-84 years, in the Prostate Cancer Prevention Trial during 1994-2003. Cases (n = 1,658) were frequency matched to controls (n = 1,803) on age, treatment, and prostate cancer family history. Phospholipid fatty acids were extracted from serum, and concentrations of ω-3, ω-6, and trans-fatty acids (TFAs) were expressed as proportions of the total. Logistic regression models estimated odds ratios and 95% confidence intervals of associations of fatty acids with prostate cancer by grade. No fatty acids were associated with low-grade prostate cancer risk. Docosahexaenoic acid was positively associated with high-grade disease (quartile 4 vs. 1: odds ratio (OR) = 2.50, 95% confidence interval (CI): 1.34, 4.65); TFA 18:1 and TFA 18:2 were linearly and inversely associated with risk of high-grade prostate cancer (quartile 4 vs. 1: TFA 18:1, OR = 0.55, 95% CI: 0.30, 0.98; TFA 18:2, OR = 0.48, 95% CI: 0.27, 0.84). The study findings are contrary to those expected from the pro- and antiinflammatory effects of these fatty acids and suggest a greater complexity of effects of these nutrients with regard to prostate cancer risk.     

Soy and isoflavone intake are associated with reduced risk of ovarian cancer in southeast china

To investigate whether intake of soy and isoflavones has an inverse association with ovarian cancer risk, a case-control study was conducted in Hangzhou, China. Cases were 254 patients with histologically confirmed epithelial ovarian cancer. The 652 controls comprised 340 hospital visitors, 261 non-neoplastic hospital outpatients, and 51 women recruited from the community. Habitual dietary intakes including 9 soy foods were measured by face-to-face interview using a validated and reliable food-frequency questionnaire. Unconditional logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) accounting for age, demographic characteristics, hormonal factors, and total energy intake. Intake of soy and isoflavones was inversely related to the risk of ovarian cancer. Compared with the highest versus the lowest quartile intake, the ORs were 0.50 (95% CI = 0.31-0.82) for total soy foods and 0.51 (95% CI = 0.31-0.85) for isoflavones. Among subgroups of soy foods and isoflavones, the ORs for soybeans, bean curd, daidzein, genistein, and glycitein were 0.35 (95% CI = 0.22-0.58), 0.49 (95% CI = 0.29-0.81), 0.52 (95% CI = 0.31-0.87), 0.50 (95% CI = 0.30-0.84), and 0.59 (95% CI = 0.35-0.97), respectively.     

Soy Isoflavones Intake and Obesity in Chinese Adults: A Cross-Sectional Study in Shanghai,China

This study was designed to examine the association of soy isoflavones (SI) intake with different body measurements indicative of obesity in Chinese adults of Shanghai, a population consuming foods rich in SI. This study used baseline data from the Shanghai Gaofeng cohort study. SI intake was measured by using a self-reported food frequency questionnaire (FFQ). A restricted cubic spline (RCS) was performed to examine the possible nonlinear relationship of SI intake with obesity. A logistic regression model was applied to estimate the odds ratios (OR) and 95% confidence interval (CI). Compared with the lowest tertile group of SI intake, the highest tertile group had a lower prevalence of obesity and central obesity. The OR for overall obesity was 0.91 (95% CI: 0.85, 0.98) in the highest versus the lowest SI tertile group; the associations differed by sex and menopausal status. A negative association was also observed between SI intake and central obesity, and a significant modifying effect of sex was found on the association. No significant interactions were observed between SI intake and physical activity (PA) levels. Our results suggest that Chinese adults with higher dietary intake of SI may be less likely to be obese, particularly for postmenopausal women.     

Plant foods, antioxidants, and prostate cancer risk: findings from case-control studies in Canada

Epidemiological data on most cancer sites suggest that consumption of plant foods, which contain high levels of antioxidants, might slow or prevent the appearance of cancer. We used data from three case-control studies to test this hypothesis. The total study population consisted of 617 incident cases of prostate cancer and 636 population controls from Ontario, Quebec, and British Columbia. Dietary information was collected by an in-person interview with a detailed quantitative dietary history. Unconditional logistic regression analyses were performed to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A decreasing, statistically significant association was found with increasing intakes of green vegetables (OR = 0.54, 95% CI = 0.40-0.71 for 4th quartile), tomatoes (OR = 0.64, 95% CI = 0.45-0.91), beans/lentils/nuts (OR = 0.69, 95% CI = 0.53-0.91), and cruciferous vegetables (OR = 0.69, 95% CI = 0.52-0.91 for 3rd quartile). Higher intakes of fruit were associated with higher ORs (OR = 1.51, 95% CI = 1.14-2.01 for 4th quartile), an effect that was seen for total fruit and citrus fruit, as well as for all other noncitrus fruits. Among the grains, refined-grain bread intake was associated with a decrease in risk (OR = 0.65 for 4th quartile), whereas whole-grain breakfast cereals were associated with a higher risk for prostate cancer. Of all the antioxidant nutrients studied, the ORs were higher with higher intakes of cryptoxanthin (OR = 1.44, 95% CI = 1.09-1.89 for 4th quartile). Exposure to certain dietary components of plant origin, which are potentially modifiable, indicates the theoretical scope for reducing the risk from prostate cancer. Future experimental studies or trials are warranted for further understanding.     

Dietary factors and oral cancer: a case-control study in Greater Metropolitan São Paulo, Brazil

Dietary factors associated with oral cancer were investigated in a case-control hospital-based study in the city of S?o Paulo, Brazil, from 1998 to 2002. A total of 835 subjects, 366 with histologically confirmed incident cases of oral-cavity or pharyngeal cancer and 469 controls participated in the study. Dietary data were collected with a food frequency questionnaire (FFQ). Odds ratios (OR) and 95% confidence intervals (95%CI) were obtained from unconditional logistic regression, adjusted for potential confounders. Inverse associations with risk of oral cancer were found for the highest intake of beans, OR = 0.37 (95%CI: 0.22-0.64), raw vegetables, OR = 0.51 (95%CI: 0.29-0.93) and the intermediate tertile of rice and pasta intake, OR = 0.56 (95%CI: 0.38-0.83). Positive associations were observed for the highest intake of eggs, OR = 1.84 (95%CI: 1.23-2.75), potatoes, OR = 2.22 (95%CI: 1.53-3.25), and milk, OR= 1.80 (95%CI: 1.09-2.98). Some traditional Brazilian foods like rice and beans emerged as protective factors against oral cancer, independently of other risk factors.     

环境和遗传因素与广东前列腺癌关系的病例对照研究

目的 探索我国南方前列腺癌发生与环境危险因素及基因多态性的关系.方法 采用以医院为基础的1:1匹配病例-对照设计,以病理确诊的前列腺癌住院患者为病例,其他疾病住院患者为对照.共完成142对病例和对照的问卷调查,采集85例病例和82例对照的血样.采用聚合酶链反应(PCR)、限制性片段长度多态性聚合酶链反应(PCR-RFLP)检测外周血细胞色素P450家族1A1(CYP1A1)、家族17(CYP17)和雄激素受体(AR)的基因型.应用条件logistic回归模型进行多因素分析.结果 与对照相比,首次遗精年龄小于18岁(OR=2.90,95%CI值:1.76～4.80)、首次性生活年龄≤24岁(OR=2.38,95%C/值:1.14～4.96)、35岁前每周性生活频率高(OR=1.80,95%CI值:1.19～2.70)、有肿瘤家族史(OR=2.70,95%C/值:1.31～5.58)、每天摄人猪肉(OR=2.27,95%C/值:1.38～3.70)是前列腺癌发生的危险因素,而吃水果多和喝绿茶是保护因素,OR值分别为0.25(95%C/值:0.08～0.75)和0.52(95%C/值:0.28～0.96).基因多态性分析发现携带CYP17A1/A2基因型与A1/A1相比,OR值为1.78(95%C/值:0.70～4.53),A2/A2基因型OR值为2.57(95%CI值:0.91～7.25),提示该基因多态性A2突变型与前列腺癌发生有关.在遗传与环境因素交互作用分析中发现遗精年龄早、癌家族史与CYP17基因多态性存在交互作用,OR值分别为13.35(95%C/值:1.58～113.00)和4.01(95%C/值:1.22～13.17).结论 性生活史、饮食、癌家族史与前列腺癌发生相关联.CYP17基因型的突变可能是前列腺癌发生的危险因素,提示遗传与环境因素共同在前列腺癌发生中起作用.     

S-(−)equol producing status not associated with breast cancer risk among low isoflavone-consuming US postmenopausal women undergoing a physician-recommended breast biopsy

Soy foods are the richest sources of isoflavones, mainly daidzein and genistein. Soy isoflavones are structurally similar to the steroid hormone 17β-estradiol and may protect against breast cancer. S-(−)equol, a metabolite of the soy isoflavone daidzein, has a higher bioavailability and greater affinity for estrogen receptor β than daidzein. Approximately one-third of the Western population is able to produce S-(−)equol, and the ability is linked to certain gut microbes. We hypothesized that the prevalence of breast cancer, ductal hyperplasia, and overall breast pathology will be lower among S-(−)equol producing, as compared with nonproducing, postmenopausal women undergoing a breast biopsy. We tested our hypothesis using a cross-sectional study design. Usual diets of the participants were supplemented with 1 soy bar per day for 3 consecutive days. Liquid chromatography–multiple reaction ion monitoring mass spectrometry analysis of urine from 143 subjects revealed 25 (17.5%) as S-(−)equol producers. We found no statistically significant associations between S-(−)equol producing status and overall breast pathology (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.23-1.89), ductal hyperplasia (OR, 0.84; 95% CI, 0.20-3.41), or breast cancer (OR, 0.56; 95% CI, 0.16-1.87). However, the mean dietary isoflavone intake was much lower (0.3 mg/d) than in previous reports. Given that the amount of S-(−)equol produced in the gut depends on the amount of daidzein exposure, the low soy intake coupled with lower prevalence of S-(−)equol producing status in the study population favors toward null associations. Findings from our study could be used for further investigations on S-(−)equol producing status and disease risk.