Proceedings of the American Association for Cancer Research (AACR) 100th Annual Meeting, April 18-22, 2009, Denver, Colorado. Abstract 73. Philadelphia, PA: American Association for Cancer Research, 2009 Apr; 50:18
Experimental studies (animal and in vitro) suggest that dietary antioxidants may provide protection against the DNA damage induced by ionizing radiation (IR). However, data from radiation-exposed human populations supporting these associations are limited. Airline pilots are exposed to cosmic IR, an efficient inducer of chromosome aberrations (CA) which have been shown to be associated with increased cancer risk. We examined the association between the frequency of translocations (the most stable form of CA) and the intakes of vitamins C and E, and carotenoids among 82 male airline pilots. All study subjects completed a self-administered questionnaire with information on occupational history and lifestyle factors. Dietary antioxidant intakes were estimated using a validated semi-quantitative food frequency questionnaire and were energy-adjusted. Translocations were scored in an average of 1039 cell equivalents (CE) per subject using fluorescence in situ hybridization with whole chromosome paints, and expressed per 100 CE. Negative binomial regression was used to estimate rate ratios (RRs) and 95% confidence intervals (CIs), adjusted for age, flight experience in years, self-reported personal diagnostic X-ray procedures, military service, and lifestyle factors. We observed a significant and inverse association between the frequency of translocations and the intake of vitamin C, ß-cryptoxanthin, lutein-zeaxanthin (hereafter referred to as lutein), and ß-carotene from food. The adjusted RRs (95% CIs) for subjects in the highest compared with the lowest tertile were 0.56 (0.38, 0.82) for vitamin C, 0.66 (0.44, 0.97) for ß-cryptoxanthin, and 0.60 (0.41, 0.86) for lutein. For ß-carotene, the adjusted RR (95% CI) was significant for subjects in the middle but of borderline significance in the highest tertile compared with those in the lowest tertile: 0.61 (0.41, 0.91) and 0.70 (0.47, 1.03), respectively. Translocation frequency was not significantly associated with the intake of vitamin E, a-carotene, or lycopene from food; total vitamin C or E from food and supplements; or the use of vitamin E or C, or multivitamin supplements. However, the adjusted RR (95% CI) for subjects who consumed = median compared with < median servings/week of high vitamin C fruits and vegetables was 0.62 (0.44, 0.87), of citrus fruits was 0.64 (0.47, 0.87), and of green leafy vegetables was 0.59 (0.43, 0.81). The strongest inverse associations were observed for subjects with = median compared with < median intakes of combinations of antioxidants from food: vitamins C and E (RR: 0.42; 95% CI: 0.26, 0.68); and vitamins C and E, ß-carotene, ß-cryptoxanthin, and lutein (RR: 0.27; 95% CI: 0.14, 0.55). In conclusion, our data suggest that the combined intake of vitamins C and E, ß-carotene, ß-cryptoxanthin, and lutein from food or a diet high in their food sources may protect against IR-induced DNA damage.
Proceedings of the American Association for Cancer Research (AACR) 100th Annual Meeting, April 18-22, 2009, Denver, Colorado