Pooled analysis of studies on DNA adducts and dietary vitamins.

OBJECTIVES: There is some evidence that dietary components that are rich in antioxidant and vitamins are inversely associated with DNA adduct levels induced by environmental carcinogens such as polycyclic aromatic hydrocarbons, although the epidemiologic data are inconsistent. This study addresses the association between vitamins, DNA adducts and smoking. METHODS: A combined analysis of individual data on the association between bulky DNA adducts and dietary vitamins was conducted. A Medline search was performed to identify studies on healthy subjects in which smoking and vitamins intake information were available, and bulky DNA adducts were measured in peripheral blood with 32P-postlabelling. Eight published studies met the eligibility criteria, and individual data from 7 data sets including 2758 subjects were obtained. GSTM1 and GSTT1 were also available on all the subjects. RESULTS: Vitamin E was inversely significantly associated with DNA adducts after adjustment for possible confounding factors. Vitamins A and C were not independent predictors of DNA adducts. A stratified analysis showed that vitamin A had a significant inverse association with DNA adducts in ever smokers only. CONCLUSIONS: This result is relevant to planning any future chemo-preventive interventions directed to high risk subgroups of the population, for cancer prevention.

Comparison of knowledge and attitudes toward cancer among African Americans.

BACKGROUND: It has been noted that the African American population in the U.S. bears disproportionately higher cancer morbidity and mortality rates than any racial and ethnic group for most major cancers. Many studies also document that decreased longevity is associated with low educational attainment and other markers of low socioeconomic status (SES), both of which are prevalent in African American communities across the nation. Evidence suggests that this phenomenon may be due to attitudes that reflect a lack of knowledge surrounding facts about cancer awareness and prevention. This study was designed to yield data concerning the general population's attitudes toward cancer, taking into consideration racial and/or socioeconomic differences in the population studied. RESULTS: Two hundred and fifteen subjects participated in the survey, of which 74% (159/215) defined themselves as African-American, 20% were White, and 6% were of other races. While only 38% of the study population was able to identify at least 5 risk factors associated with cancer, a lower proportion of African Americans identified at least 5 risk factors than whites (34% vs. 53%, p = 0.03). In addition, a slightly higher percentage of African Americans (10%) were not aware of the definition of a clinical trial when compared to whites (8%, p > 0.1). Of those aware of the definition of a clinical trial, African Americans were more reluctant to participate in clinical trials, with 53% answering no to participation compared to 15% of whites (p = 0.002). CONCLUSION: When comparing results to a similar study conducted in 1981, a slight increase in cancer knowledge in the African American population was observed. Our results suggest that while knowledge of cancer facts has increased over the years amongst the general population, African Americans and lower income populations are still behind. This may affect their risk profile and cancer early detection.