Rice consumption and cancer incidence in US men and women

While both the 2012 and 2014 Consumer Reports concerned arsenic levels in US rice, no previous study has evaluated long-term consumption of total rice, white rice and brown rice in relation to risk of developing cancers. We investigated this in the female Nurses' Health Study (1984-2010), and Nurses' Health Study II (1989-2009), and the male Health Professionals Follow-up Study (1986-2008), which included a total of 45,231 men and 160,408 women, free of cancer at baseline. Validated food frequency questionnaires were used to measure rice consumption at baseline and repeated almost every 4 years thereafter. We employed Cox proportional hazards regression model to estimate multivariable relative risks (RRs) and 95% confidence intervals (95% CIs). During up to 26 years of follow-up, we documented 31,655 incident cancer cases (10,833 in men and 20,822 in women). Age-adjusted results were similar to multivariable-adjusted results. Compared to participants with less than one serving per week, the multivariable RRs of overall cancer for individuals who ate at least five servings per week were 0.97 for total rice (95% CI: 0.85-1.07), 0.87 for white rice (95% CI: 0.75-1.01), and 1.17 for brown rice (95% CI: 0.90-1.26). Similar non-significant associations were observed for specific sites of cancers including prostate, breast, colon and rectum, melanoma, bladder, kidney, and lung. Additionally, the null associations were observed among European Americans and non-smokers, and were not modified by BMI. Long-term consumption of total rice, white rice or brown rice was not associated with risk of developing cancer in US men and women

Long-term use of antibiotics and risk of colorectal adenoma

Objective—Recent evidence suggests that antibiotic use, which alters the gut microbiome, is associated with an increased risk of colorectal cancer. However, the association between antibiotic use and risk of colorectal adenoma, the precursor for the majority of colorectal cancers, has not been investigated. Design—We prospectively evaluated the association between antibiotic use at age 20–39 and 40–59 (assessed in 2004) and recent antibiotic use (assessed in 2008) with risk of subsequent colorectal adenoma among 16,642 women aged ≥60 enrolled in the Nurses’ Health Study who underwent at least one colonoscopy through 2010. We used multivariate logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results—We documented 1,195 cases of adenoma. Increasing duration of antibiotic use at age 20–39 (Ptrend=0.002) and 40–59 (Ptrend=0.001) was significantly associated with an increased risk of colorectal adenoma. Compared to non-users, women who used antibiotics for ≥2 months between age 20–39 had a multivariable OR of 1.36 (95% CI: 1.03–1.79). Women who used ≥2 months of antibiotics between age 40–59 had a multivariable OR of 1.69 (95% CI: 1.24–2.31). The associations were similar for low-risk vs. high-risk adenomas (size ≥1 cm, or with tubulovillous/villous histology, or ≥3 detected lesions), but appeared modestly stronger for proximal compared with distal adenomas. In contrast, recent antibiotic use within the past 4 years was not associated with risk of adenoma (Ptrend=0.44). Conclusions—Long-term antibiotic use in early to middle adulthood was associated with increased risk of colorectal adenoma

Pre-Diagnostic Leukocyte Genomic DNA Methylation and the Risk of Colorectal Cancer in Women

Background: Abnormal one-carbon metabolism may lead to general genomic (global) hypomethylation, which may predispose an individual to the development of colorectal neoplasia. Methods: We evaluated the association between pre-diagnostic leukocyte genomic DNA methylation level and the risk of colorectal cancer in a nested case-control study of 358 colorectal cancer cases and 661 matched controls within the all-female cohort of the Nurses’ Health Study (NHS). Among control subjects, we further examined major plasma components in the one-carbon metabolism pathway in relation to genomic DNA methylation level. Liquid chromatography/tandem mass spectrometry was used to examine leukocyte genomic DNA methylation level. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression. Results: Overall genomic DNA methylation level was not associated with the risk of colorectal cancer (p for trend, 0.45). Compared with women in the lowest quintile of methylation, the multivariate OR of colorectal cancer risk was 1.32 (95% CI, 0.82–2.13) for those in the highest quintile. We did not find significant associations between major plasma components of one-carbon metabolism or risk factors for colorectal cancer and genomic DNA methylation level (all p for trend >0.05). Also, neither one-carbon metabolism-related plasma components nor well-known risk factors for colorectal cancer modified the association between genomic DNA methylation level and the risk of colorectal cancer (all p for interaction >0.05). Conclusions: We found no evidence that hypomethylation of leukocyte genomic DNA increases risk of colorectal cancer among women. Additional studies are needed to investigate the association between pre-diagnostic genomic DNA methylation level and colorectal cancer risk among diverse populations

Preventable fractions of colon and breast cancers by increasing physical activity in Brazil: perspectives from plausible counterfactual scenarios

Background: Physical activity is associated with lower risk of colon and breast cancers. Herein we estimated preventable fractions of colon and breast cancers in Brazil by increasing population-wide physical activity to different counterfactual scenarios. Methods: We used data from a representative national survey in Brazil and corresponding relative risks of colon and postmenopausal breast cancers from a meta-analysis. Estimated cancer incidence was retrieved from GLOBOCAN and Brazilian National Cancer Institute. Five counterfactual scenarios for physical activity were considered: (i) theoretical minimum risk exposure level (≥8,000 metabolic equivalent of tasks-minute/week – MET-min/week); (ii) physical activity recommendation (≥600 MET-min/week); (iii) a 10% reduction in prevalence of insufficient physical inactivity (<600 MET-min/week); (iv) physical activity level in each state equals the most active state in Brazil; (v) closing the gender differences in physical activity. Results: About 19% (3,630 cases) of colon cancers and 12% (6,712 cases) of postmenopausal breast cancers could be prevented by increasing physical activity to ≥8,000 MET-min/week. Plausible counterfactual scenarios suggested the following impact on cancer prevention: reaching physical activity recommendation: 1.3% (1,113 cases) of breast and 6% (1,137 cases) of colon; 10% reduction in physical inactivity prevalence: 0.2% (111 cases) of breast and 0.6% (114 cases) of colon; most active state scenario: 0.3% (168 cases) of breast and 1% (189 cases) of colon; reducing gender differences in physical activity: 1.1% (384 cases) of breast and 0.6% (122 cases) of colon. Conclusions: High levels of physical activity are required to achieve sizable impact on breast and colon cancer prevention in Brazil

Post Diagnosis Diet Quality and Colorectal Cancer Survival in Women

Background: Dietary factors are known to influence colorectal cancer (CRC) risk, however, their association with CRC survival is unclear. Therefore, we prospectively examined the association between diet quality scores, dietary patterns and colorectal cancer (CRC) survival. Methods: 1201 women diagnosed with stage I–III CRC between 1986 and 2008, were followed through 2010. Diet was assessed via a food frequency questionnaire administered at least 6 months after diagnosis. We computed the Alternate Healthy Eating Index-2010 (AHEI-2010), alternate Mediterranean Diet score (aMED) and Dietary Approaches to Stop Hypertension score (DASH) and derived two dietary patterns, Western (unhealthy) and prudent (healthy), by principal component analysis for each woman. Results: During follow-up, we documented 435 deaths, including 162 from CRC. After adjusting for potential confounders, only a higher AHEI-2010 score was significantly associated with lower overall mortality (HR comparing extreme quintiles = 0.71, 95% CI 0.52–0.98, p trend = 0.01) as well as borderline significantly with lower risk of CRC mortality by the trend test (HR Q5 vs Q1 = 0.72, 95% CI = 0.43–1.21, p trend = 0.07). When AHEI-2010 components were examined separately, inverse associations for overall mortality were primarily accounted for by moderate alcohol intake (HR comparing abstainers vs 5–15 g/d = 1.30, 95%CI = 1.05–1.61) and lower intake of sugar sweetened beverages and fruit juices combined (HR for each additional serving = 1.11, 95% CI = 1.01–1.23). No other diet quality score or dietary pattern was associated with overall or CRC-specific mortality. Conclusion: Higher AHEI-2010 score may be associated with lower overall mortality, moderate alcohol consumption and lower consumption of sugar sweetened beverages and juices combined appeared to account for most of the observed associations

Dietary Patterns and Risk of Colorectal Cancer Subtypes Classified by Fusobacterium nucleatum in Tumor Tissue

Importance—Fusobacterium nucleatum appears to play a role in colorectal carcinogenesis through suppression of host immune response to tumor. Evidence also suggests that diet influences intestinal F. nucleatum. However, the role of F. nucleatum in mediating the relationship between diet and the risk of colorectal cancer is unknown. Objective—To test the hypothesis that the associations of prudent diets (rich in whole grains and dietary fiber) and Western diets (rich in red and processed meat, refined grains, and desserts) with colorectal cancer risk may differ according to the presence of F. nucleatum in tumor tissue. Design—Prospective cohort study. Setting—The Nurses’ Health Study (1980–2012) and the Health Professionals Follow-up Study (1986–2012). Participants—121,700 US female nurses and 51,529 US male health professionals aged 30 to 55 years and 40 to 75 years, respectively, at enrollment. Exposures—Prudent and Western dietary patterns. Main Outcomes and Measures—Incidence of colorectal carcinoma subclassified by F. nucleatum status in tumor tissue, determined by quantitative polymerase chain reaction. Results—We documented 1,019 incident colon and rectal cancer cases with available F. nucleatum data among predominantly white 137,217 individuals over 26–32 years of follow-up encompassing 3,643,562 person-years. The association of prudent diet with colorectal cancer significantly differed by tissue F. nucleatum status (Pheterogeneity = .01). Prudent diet score was associated with a lower risk of F. nucleatum-positive cancers [Ptrend = .003; multivariable hazard ratio of 0.43 (95% confidence interval 0.25–0.72) for the highest vs. the lowest prudent score quartile], but not with F. nucleatum-negative cancers (Ptrend = .47). Dietary component analyses suggested possible differential associations for the cancer subgroups according to intakes of dietary fiber (Pheterogeneity = .02). There was no significant heterogeneity between the subgroups according to Western dietary pattern scores (Pheterogeneity = .23). Conclusions and Relevance—Prudent diets rich in whole grains and dietary fiber are associated with a lower risk for F. nucleatum-positive colorectal cancer but not F. nucleatum-negative cancer, supporting a potential role for intestinal microbiota in mediating the association between diet and colorectal neoplasms

Habitual intake of flavonoid subclasses and risk of colorectal cancer in two large prospective cohorts

Background: Flavonoids inhibit the growth of colon cancer cells in vitro. In a secondary analysis of a randomized controlled trial, the Polyp Prevention Trial, a higher intake of one sub-class, flavonols, was significantly associated with reduced risk of recurrent advanced adenoma. Most previous prospective studies on colorectal cancer evaluated only a limited number of flavonoid sub-classes and intake ranges, yielding inconsistent results.  Objective: To examine whether higher habitual dietary intakes of flavonoid subclasses (flavonols, flavones, flavanones, flavan-3-ols and anthocyanins) are associated with lower risk of colorectal cancer.  Design: Using data from validated food frequency questionnaires administered every four years and an updated flavonoid food composition database flavonoid intakes were calculated for 42,478 male participants from the Health Professionals Follow-up Study and for 76,364 female participants from the Nurses’ Health Study.  Results: During up to 26 years of follow-up, 2,519 colorectal cancer cases (1,061 in men, 1,458 in women) were documented. Intakes of flavonoid subclasses were not associated with risk of colorectal cancer in either cohort. Pooled multivariable adjusted relative risks (95% confidence interval) comparing the highest with the lowest quintile were 1.04 (0.91, 1.18) for flavonols; 1.01 (0.89, 1.15) for flavones; 0.96 (0.84, 1.10) for flavanones; 1.07 (0.95, 1.21) for flavan-3-ols; and 0.98 (0.81, 1.19) for anthocyanins (all p-values for heterogeneity by sex >0.19). In subsite analyses, flavonoid intake was also not associated with colon or rectal cancer risk.  Conclusion: Our findings do not support the hypothesis that a higher habitual intake of any flavonoid sub-class decreases the risk of colorectal cancer

Polyclonal human antibodies against glycans bearing red meat-derived non-human sialic acid N-glycolylneuraminic acid are stable, reproducible, complex and vary between individuals: Total antibody levels are associated with colorectal cancer risk.

BACKGROUND: N-glycolylneuraminic acid (Neu5Gc) is a non-human red-meat-derived sialic acid immunogenic to humans. Neu5Gc can be metabolically incorporated into glycan chains on human endothelial and epithelial surfaces. This represents the first example of a "xeno-autoantigen", against which circulating human "xeno-autoantibodies" can react. The resulting inflammation ("xenosialitis") has been demonstrated in human-like Neu5Gc-deficient mice and contributed to carcinoma progression via antibody-mediated inflammation. Anti-Neu5Gc antibodies have potential as biomarkers for diseases associated with red meat consumption such as carcinomas, atherosclerosis, and type 2 diabetes. METHODS: ELISA assays measured antibodies against Neu5Gc or Neu5Gc-glycans in plasma or serum samples from the Nurses' Health Studies, the Health Professionals Follow-up Study, and the European Prospective Investigation into Cancer and Nutrition, including inter-assay reproducibility, stability with delayed sample processing, and within-person reproducibility over 1-3 years in archived samples. We also assessed associations between antibody levels and coronary artery disease risk (CAD) or red meat intake. A glycan microarray was used to detected antibodies against multiple Neu5Gc-glycan epitopes. A nested case-control study design assessed the association between total anti-Neu5Gc antibodies detected in the glycan array assay and the risk of colorectal cancer (CRC). RESULTS: ELISA assays showed a wide range of anti-Neu5Gc responses and good inter-assay reproducibility, stability with delayed sample processing, and within-person reproducibility over time, but these antibody levels did not correlate with CAD risk or red meat intake. Antibodies against Neu5Gc alone or against individual Neu5Gc-bearing epitopes were also not associated with colorectal cancer (CRC) risk. However, a sialoglycan microarray study demonstrated positive association with CRC risk when the total antibody responses against all Neu5Gc-glycans were combined. Individuals in the top quartile of total anti-Neu5Gc IgG antibody concentrations had nearly three times the risk compared to those in the bottom quartile (Multivariate Odds Ratio comparing top to bottom quartile: 2.98, 95% CI: 0.80, 11.1; P for trend = 0.02). CONCLUSIONS: Further work harnessing the utility of these anti-Neu5Gc antibodies as biomarkers in red meat-associated diseases must consider diversity in individual antibody profiles against different Neu5Gc-bearing glycans. Traditional ELISA assays for antibodies directed against Neu5Gc alone, or against specific Neu5Gc-glycans may not be adequate to define risk associations. Our finding of a positive association of total anti-Neu5Gc antibodies with CRC risk also warrants confirmation in larger prospective studies

Investigation of scaling effect on power factor of permanent magnet Vernier machines for wind power application

This study investigates the scaling effect on power factor of surface mounted permanent magnet Vernier (SPM-V) machines with power ratings ranging from 3 kW, 500 kW, 3 MW to 10 MW. For each power rating, different slot/pole number combinations have been considered to study the influence of key parameters including inter-pole magnet leakage and stator slot leakage on power factor. A detailed analytical modelling, incorporating these key parameters, is presented and validated with two-dimensional finite-element analysis for different power ratings and slot/pole number combinations. The study has revealed that with scaling (increasing power level), significant increase in electrical loading combined with the increased leakage fluxes, i.e. (i) magnet leakage flux due to large coil pitch to rotor pole pitch ratio, (ii) magnet inter-pole leakage flux and (iii) stator slot leakage flux, reduces the ratio of armature flux linkage to permanent magnet flux linkage and thereby has a detrimental effect on the power factor. Therefore, unlike conventional SPM machines, the power factor of SPM-V machines is found to be significantly reduced at high power ratings