Relationship between smoking, dietary intakes and plasma levels of vitaminE and beta-carotene in matched maternal-cord pairs

The concentrations of tocopherols and carotenoids are lowered in umbilical cord blood plasma, which may have a negative effect on antioxidant protecti on in neonates. Smoking may adversely affect dietary intakes and plasma con centrations of carotenoids. The dietary intakes of vitamin E and beta-carot ene were assessed in 66 pregnant women (31 smokers and 35 non-smokers) betw een 10 and 20 weeks gestation using a food frequency questionnaire. The con centrations of alpha-tocopherol and beta-carotene were measured in maternal plasma at the time of the dietary assessment, and in the matched umbilical cords of their newborn after delivery. In smoking and non-smoking mothers, the mean intakes of vitamin E (9.3 [SD 5] and 82 [SD 5] mgd(-1)) and beta- carotene (3464 [SD 1885] and 2977 [SD 1503] mu gd(-1)) were not significant ly different. The plasma concentrations of alpha-tocopherol (20.8 [SD 4] an d 20.5 [SD 4] mu molL(-1)), the alpha-tocopherol to lipid ratios (3.2 [SD 0 .8] and 3.5 [SD 0.8]) and the plasma concentrations of beta-carotene (0.22 [SD 0.1] and 0.22 [SD 0.1] mu molL(-1)) were not significantly different in smoking and non-smoking mothers;. There were no significant differences in plasma alpha-tocopherol (7.4 [SD 2] and 7.3 [SD 2] mu molL(-1)), in alpha- tocopherol to lipid ratios (3.2 [SD 0.6] and 2.8 [SD 0.6]) or in beta-carot ene concentrations 10.05 [SD 0.04] and 0.03 [SD 0.02] mu molL(-1)) in cords from newborns of smoking and non-smoking mothers. There was a significant correlation (r = 0.41, P = 0.015) between dietary intakes and plasma concen trations of beta-carotene in non-smoking mothers, However, this relationshi p was not significant in smoking mothers (r = 0.28, P = 0.12). There were n o relationships between dietary intakes and plasma concentrations of tocoph erol. These results indicate that smoking during pregnancy does not appear to affect the dietary intakes or plasma concentrations of alpha-tocopherol and beta-carotene in pregnant women or their babies. However, smoking does influence the relationship between dietary intakes and plasma levels of bet a-carotene.