Global Environmental Influences

Coffee, Tea, or Soy Involved in Cancer? What Effects on the Human Body?

Coffee, Tea, Caffeine Intake, and Risk of Adult Glioma in Three Prospective Cohort Studies

Soy Consumption and Colorectal Cancer Risk in Humans: A Meta-Analysis

Obesity and Cancer: The Role of Dysfunctional Adipose Tissue…





Coffee, Tea, Caffeine Intake, and Risk of Adult Glioma in Three Prospective Cohort Studies

   1. Crystal N. Holick1,
   2. Scott G. Smith2,
   3. Edward Giovannucci1,2,3 and
   4. Dominique S. Michaud1,4

      Authors' Affiliations: Departments of 1Epidemiology and 2Nutrition, Harvard School of Public Health; and 3Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; and 4Department of Epidemiology and Public Health, Faculty of Medicine, Imperial College London, London, United Kingdom

Current data suggest that caffeinated beverages may be associated with lower risk of glioma. Caffeine has different effects on the brain, some of which could play a role in brain carcinogenesis, and coffee has been consistently associated with reduced risk of liver cancer, thus suggesting a potential anticarcinogenic effect. A total of 335 incident cases of gliomas (men, 133; women, 202) were available from three independent cohort studies. Dietary intake was assessed by food frequency questionnaires obtained at baseline and during follow-up. Cox proportional hazard models were used to estimate incidence rate ratios (RR) and 95% confidence intervals (CI) between consumption of coffee, tea, carbonated beverages, caffeine, and glioma risk adjusting for age and total caloric intake. Estimates from each cohort were pooled using a random-effects model. Consumption of five or more cups of coffee and tea daily compared with no consumption was associated with a decrease risk of glioma (RR, 0.60; 95% CI, 0.41-0.87; Ptrend = 0.04). Inverse, although weaker, associations were also observed between coffee, caffeinated coffee, tea, and carbonated beverages and glioma risk. No association was observed between decaffeinated coffee and glioma risk. Among men, a statistically significant inverse association was observed between caffeine consumption and risk of glioma (RR, 0.46; 95% CI, 0.26-0.81; Ptrend = 0.03); the association was weaker among women. Our findings suggest that consumption of caffeinated beverages, including coffee and tea, may reduce the risk of adult glioma, but further research is warranted to confirm these findings in other populations. Cancer Epidemiol Biomakers Prev; 19(1);39–47

Soy Consumption and Colorectal Cancer Risk in Humans: A Meta-Analysis

   1. Lin Yan1,
   2. Edward L. Spitznagel2 and
   3. Maarten C. Bosland3
      Authors' Affiliations:1USDA, ARS, Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota; 2Department of Mathematics, Washington University, St. Louis, Missouri; and 3Department of Pathology, University of Illinois at Chicago College of Medicine, Chicago, Illinois
The purpose of the present study was to determine the relationship between soy consumption and colorectal cancer risk in humans by conducting a meta-analysis of available epidemiologic studies. We systematically reviewed publications obtained through a Medline literature search and identified four cohort and seven case-control studies on soy and colorectal cancer risk that met the inclusion criteria. We extracted the risk estimate (hazard ratio, relative risk, or odds ratio) of the highest and the lowest reported categories of intake from each study and conducted this analysis using a random-effects model. Our analysis did not find that soy consumption was associated with colorectal cancer risk [combined risk estimate, 0.90; 95% confidence interval (95% CI), 0.79-1.03] nor did the separate analyses on colon cancer (combined risk estimate, 0.88; 95% CI, 0.74-1.06) and rectal cancer (combined risk estimate, 0.88; 95% CI, 0.67-1.14). However, when separately analyzed on the basis of gender, we found that soy was associated with an approximately 21% reduction in colorectal cancer risk in women (combined risk estimate, 0.79; 95% CI, 0.65-0.97; P = 0.026), but not in men (combined risk estimate, 1.10; 95% CI, 0.90-1.33). Thus, consumption of soy foods may be associated with a reduction in colorectal cancer risk in women, but not in men. Cancer Epidemiol Biomarkers Prev; 19(1); 148–58

Obesity and Cancer: The Role of Dysfunctional Adipose Tissue

   1. Rob C.M. van Kruijsdijk1,
   2. Elsken van der Wall2 and
   3. Frank L.J. Visseren1
      Departments of 1Vascular Medicine and 2Pathology and Medical Oncology, University Medical Center Utrecht, the Netherlands

Overweight and obesity are health problems of epidemic proportions, increasing the risk not only of cardiovascular disease and type 2 diabetes mellitus but also of various types of cancer. Obesity is strongly associated with changes in the physiological function of adipose tissue, leading to insulin resistance, chronic inflammation, and altered secretion of adipokines. Several of these factors, such as insulin resistance, increased levels of leptin, plasminogen activator inhibitor-1, and endogenous sex steroids, decreased levels of adiponectin, and chronic inflammation, are involved in carcinogenesis and cancer progression. This article reviews these mechanisms, focusing on adipose tissue dysfunction as a unifying causal factor. Although understanding of the link between obesity and cancer might provide therapeutic targets, preventing overweight and obesity still remains number one priority. (Cancer Epidemiol Biomarkers Prev 2009;18(10):2569–78)