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ABSTRACT: Millions of Americans use dietary supplements with little knowledge about their benefits or risks. We examined associations of various herbal/specialty supplements with lung and colorectal cancer risk. Men and women, 50 to 76 years, in the VITamins And Lifestyle cohort completed a 24-page baseline questionnaire that captured duration (years) and frequency (days per week) of use of commonly used herbal/specialty supplements. Dose was not assessed due to the lack of accurate potency information. Supplement exposure was categorized as "no use" or "any use" over the previous 10 years. Hazard ratios (HR) were estimated by multivariate Cox regression models. Incident lung (n = 665) and colorectal cancers (n = 428) were obtained from the Surveillance, Epidemiology, and End Results cancer registry. Any use of glucosamine and chondroitin, which have anti-inflammatory properties, over the previous 10 years, was associated with significantly lower lung cancer risk: HR 0.74 [95% confidence interval (95% CI), 0.58-0.94] and HR 0.72 (95% CI, 0.54-0.96) and colorectal cancer risk: HR 0.73 (95% CI, 0.54-0.98) and HR 0.65 (95% CI, 0.45-0.93), respectively. There were also statistically significantly inverse associations of fish oil: HR 0.65 (95% CI, 0.42-0.99), methylsulfonylmethane: HR 0.46 (95% CI, 0.23-0.93), and St. John's wort: HR 0.35 (95% CI, 0.14-0.85) with colorectal cancer risk. In contrast, garlic pills were associated with a statistically significant 35% elevated colorectal cancer risk. These results suggest that some herbal/specialty supplements may be associated with lung and colorectal cancer risk; however, these products should be used with caution. Additional studies examining the effects of herbal/specialty supplements on risk for cancer and other diseases are needed.
Cancer Epidemiology Biomarkers & Prevention 06/2009; 18(5):1419-28. · 4.12 Impact Factor
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ABSTRACT: Several, but not all, studies have observed increased risks of testicular germ cell cancer (TGCC) associated with bicycling and other recreational activities. To further examine whether physical activity (PA) in adolescence is associated with TGCC risk, the authors conducted a case-control study in western Washington State.
Cases (n = 391) were men diagnosed with TGCC, who were identified through a population-based cancer registry. Controls (n = 1,023) were men identified from the general population in western Washington State by using random digit telephone dialing. Participants were queried about various specific PA in grades 7-12 including bicycling, horseback riding, competitive sports, physical education class, as well as moderate, vigorous, and sedentary activities in general.
In multivariate analyses, bicycling, vigorous-intensity activities, and sedentary activities were not associated with TGCC risk, while horseback riding and wrestling were associated with decreased risks, and moderate-intensity activities, soccer, basketball, and intermediate duration of competitive activities were associated with increased risks.
The lack of internal consistency of the findings within the current study and of findings among prior studies suggests that PA contributes little, if any, to the risk of TGCC.
Cancer Causes and Control 05/2009; 20(8):1281-90. · 2.88 Impact Factor
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ABSTRACT: To describe and compare the prevalence of physical activity (PA) in relation to veteran status and use of Department of Veterans Affairs (VA) facilities.
Data were obtained from the 2003 Behavioral Risk Factor Surveillance System surveys of US adults. Veteran status, VA health care use, and PA were determined in 245,564 adults. Individuals were classified as inactive, insufficiently active, or meeting recommendations for moderate or strenuous PA. To adjust for confounding, we used model-based direct adjustment and chi-square tests corrected for the survey design.
After adjusting for age and gender, the prevalence of inactivity was significantly lower (16.2% vs 20.5%), and meeting PA recommendations was significantly greater (46.0% vs 42.0%) in veterans than in nonveterans (P < 0.0001). Compared with veterans who did not obtain their health care from the VA, VA users were more likely to be inactive (20.8% vs 14.7%) and less likely to be insufficiently active (34.1% vs 38.2%) or meet recommendations (45.1% vs 47.1%; P < 0.0001). Differences in PA levels between veterans and nonveterans and between VA users and nonusers did not change substantially after additional adjustment for education, race/ethnicity, and smoking.
Despite the high level of PA required of active duty military personnel, only a minority of veterans met PA recommendations, and the prevalence of inactivity was particularly high in VA users. These findings suggest a large potential to increase PA and improve health in VA users.
Medicine and science in sports and exercise 04/2009; 41(5):1006-13. · 3.71 Impact Factor
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ABSTRACT: High-dose beta-carotene supplementation in high-risk persons has been linked to increased lung cancer risk in clinical trials; whether effects are similar in the general population is unclear. The authors examined associations of supplemental beta-carotene, retinol, vitamin A, lutein, and lycopene with lung cancer risk among participants, aged 50-76 years, in the VITamins And Lifestyle (VITAL) cohort Study in Washington State. In 2000-2002, eligible persons (n = 77,126) completed a 24-page baseline questionnaire, including detailed questions about supplement use (duration, frequency, dose) during the previous 10 years from multivitamins and individual supplements/mixtures. Incident lung cancers (n = 521) through December 2005 were identified by linkage to the Surveillance, Epidemiology, and End Results cancer registry. Longer duration of use of individual beta-carotene, retinol, and lutein supplements (but not total 10-year average dose) was associated with statistically significantly elevated risk of total lung cancer and histologic cell types; for example, hazard ratio = 2.02, 95% confidence interval: 1.28, 3.17 for individual supplemental lutein with total lung cancer and hazard ratio = 3.22, 95% confidence interval: 1.29, 8.07 for individual beta-carotene with small-cell lung cancer for >4 years versus no use. There was little evidence for effect modification by gender or smoking status. Long-term use of individual beta-carotene, retinol, and lutein supplements should not be recommended for lung cancer prevention, particularly among smokers.
American journal of epidemiology 02/2009; 169(7):815-28. · 5.59 Impact Factor
