Publications (37) View all
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Article: Dietary and supplemental folate and the risk of left- and right-sided colorectal cancer.
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ABSTRACT: Epidemiological evidence suggests that folate may lower the risk of colorectal cancer (CRC) although studies have been inconsistent and some have indicated differences in the effects of naturally occurring dietary folate and the synthetic form of this vitamin, folic acid. Most studies to date have considered CRC as a single disease; however, cancers that develop on the left and right sides of the colorectum display important phenotypic differences, suggesting they may also have different risk factors. A population-based case-control study was conducted in Western Australia to examine the relationship between intake of both natural dietary folate and supplements containing folic acid and the risk of left- and right-sided CRC. Data were available for 850 cases (575 left-sided and 275 right-sided) and 958 controls. Odds ratios were calculated using multinomial logistic regression models. There was no association between natural dietary folate intake and risk of either left-or right-sided CRC. Supplement use similarly had no significant effect on right-sided CRC. However, long-term supplement users (4+ yr) were at lower risk of left-sided CRC than those who had not taken supplements (OR = 0.65, 95% CI, 0.50-0.86) and there was a significant trend in risk reduction as duration of use increased (P < 0.01).Nutrition and Cancer 10/2012; 64(7):937-45. · 2.78 Impact Factor -
Article: Author's Response.
Journal of the Academy of Nutrition and Dietetics. 05/2012; 112(5):610-1. -
Article: Quantitative exposure metrics for sleep disturbance and their association with breast cancer risk.
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ABSTRACT: PURPOSE: It has been acknowledged by those in the field of sleep epidemiology that the current measures of sleep used in many epidemiological studies do not adequately capture the complexity and variability of sleep. A number of ways to improve the measurement of sleep have been proposed. This study aimed to assess the relationship between novel 'sleep disturbance' metrics, as expanded measures of sleep, and breast cancer risk. METHODS: Data for this study were derived from a population-based case-control study conducted in Western Australia between 2009 and 2011. Participants completed a self-administered questionnaire that included questions about demographic, reproductive, and lifestyle factors in addition to questions on sleep. Four metrics of exposure to sleep disturbance (cumulative, average, duration, and peak) were developed. Unconditional logistic regression was used to examine the association between metrics of sleep disturbance and breast cancer risk. RESULTS: There was no evidence to support an association between any of the sleep disturbance metrics and breast cancer risk. Compared with the reference group of unexposed women, the fully adjusted ORs for cumulative sleep disturbance (harm) metric were as follows: 1st tertile 0.90 (95 % CI: 0.72-1.13); OR for the 2nd tertile 1.04 (95 % CI: 0.84-1.29); and OR for the 3rd tertile 1.02 (95 % CI: 0.82-1.27). CONCLUSIONS: This study found no association between several metrics of sleep disturbance and risk of breast cancer. Our experience with developing metrics of sleep disturbance may be of use to others in sleep epidemiology wishing to expand their scope of sleep measurement.Cancer Causes and Control 02/2013; · 2.88 Impact Factor -
Article: Occupational pesticide exposure among Yemeni women.
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ABSTRACT: OBJECTIVES: Limited research on the nature and extent of pesticide exposure among women in developing countries is available. The aim of this study was to describe potential pesticide exposure among women living in Yemen that occurs through agricultural work. METHODS: In this cross-sectional study, 410 women who had a daughter enrolled in high school during 2011-2012 were surveyed regarding pesticide exposure. RESULTS: Of the 410 women who responded to the survey, 171 women reported working on farms during their lifetime. Of these 171 women, 147 reported working on a farm prior to marriage and 108 reported working on a farm after marriage. Among the women who reported working on a farm before marriage, 47% had worked on farms where pesticides were used. Among those women who reported working on farms after marriage, 69% of women worked on farms where pesticides were used. Among women who reported working on a farm before marriage where pesticides were used, 45% reported not using any protective equipment. This proportion was 33% among women who worked on a farm after marriage. Among the 28 commercial pesticides that were listed within the questionnaire, the banned compound dimethoate was the most commonly reported pesticide to be used on farms. CONCLUSIONS: The findings suggest that improving safe pesticide management practices among farmers and enforcing effective banning of the most toxic pesticides is needed to reduce pesticide exposure among Yemeni women.Environmental Research 01/2013; · 3.40 Impact Factor -
Article: Physical Activity and Risks of Proximal and Distal Colon Cancers: A Systematic Review and Meta-analysis.
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ABSTRACT: Background Although there is convincing epidemiological evidence that physical activity is associated with a reduced risk of colon cancer, it is unclear whether physical activity is differentially associated with the risks of proximal colon and distal colon cancers. We conducted a systematic review and meta-analysis to investigate this issue. Methods MEDLINE and EMBASE were searched for English-language cohort and case-control studies that examined associations between physical activity and the risks of proximal colon and distal colon cancers. A random-effects meta-analysis was conducted to estimate the summary relative risks (RRs) for the associations between physical activity and the risks of the two cancers. All statistical tests were two-sided. Results A total of 21 studies met the inclusion criteria. The summary relative risk of the main results from these studies indicated that the risk of proximal colon cancer was 27% lower among the most physically active people compared with the least active people (RR = 0.73, 95% confidence interval [CI] = 0.66 to 0.81). An almost identical result was found for distal colon cancer (RR = 0.74, 95% CI = 0.68 to 0.80). Conclusion The results of this systematic review and meta-analysis suggest that physical activity is associated with a reduced risk of both proximal colon and distal colon cancers, and that the magnitude of the association does not differ by subsite. Given this finding, future research on physical activity and colon cancer should focus on other aspects of the association that remain unclear, such as whether sedentary behavior and nonaerobic physical activity are associated with the risk of colon cancer.CancerSpectrum Knowledge Environment 08/2012; 104(20):1548-61. · 14.07 Impact Factor
