High dietary niacin intake is associated with decreased chromosome translocation frequency in airline pilots.

摘要

Experimental studies suggest that B vitamins such as niacin, folate, riboflavin, vitamin B₆ and vitamin B₁₂ may protect against DNA damage induced by ionising radiation (IR). However, to date, data from IR-exposed human populations are not available. We examined the intakes of these B vitamins and their food sources in relation to the frequency of chromosome translocations as a biomarker of cumulative DNA damage, in eighty-two male airline pilots. Dietary intakes were estimated by using a self-administered semi-quantitative FFQ. Translocations in peripheral blood lymphocytes were scored by using fluorescence in situ hybridisation whole-chromosome painting. Negative binomial regression was used to estimate rate ratios and 95% CI, adjusted for age and occupational and lifestyle factors. We observed a significant inverse association between translocation frequency and dietary intake of niacin (P = 0.02): adjusted rate ratio for subjects in the highest tertile compared with the lowest tertile was 0.58 (95% CI 0.40, 0.83). Translocation frequency was not associated with total niacin intake from food and supplements as well as dietary or total intake of folate, riboflavin or vitamin B₆ or B₁₂. However, the adjusted rate ratios were significant for subjects with >= median compared with < median intake of whole grains (P = 0.03) and red and processed meat (P = 0.01): 0.69 (95% CI 0.50, 0.96) and 1.56 (95% CI 1.13, 2.16), respectively. Our data suggest that a high intake of niacin from food or a diet high in whole grains but low in red and processed meat may protect against cumulative DNA damage in IR-exposed persons.