Abstract
Oxygen radical injury may be a common pathogenetic mechanism in several diseases of newborn infants; the objective of our study was to investigate nutritional and environmental factors which contribute to oxidative stress during pregnancy. Ethane, a volatile alkane produced during peroxidation of omega-3 fatty acids, was used as a non-invasive indicator of oxidative stress. Forty-four inner-city pregnant women were studied to investigate relationships between breath ethane, antioxidant nutritional status and the use of drugs, alcohol and/or tobacco. The mean age of the women was 24 ± 1 years; they were studied at 28 weeks of gestation. Nineteen of the 44 women (43%) smoked, five (11%) had positive urine drug screens and three (7%) consumed alcoholic beverages. No relationship was shown between the breath ethane of the whole group and intake of total calories, fat, protein or vitamins A, C, E, carotene or iron. Similarly, there were no correlations between breath ethane and serum vitamins A, E, E/total lipids, β-carotene, selenium, copper or manganese. No effect of drug or alcohol intake on breath ethane was noted. In contrast, there was a direct correlation between breath ethane and the number of cigarettes smoked per day (r = 0.3805, p = 0.0108). The mean breath ethane of smokers (229 ± 29 pmol l−1) was higher than that of the non-smokers (151 ± 16 pmol l−1, p = 0.0227). In the smokers (but not in the non-smokers) breath ethane correlated inversely with serum vitamin C (r = −0.5434, p = 0.0162). No correlation was shown between breath ethane and vitamin E intake in smokers, although an inverse correlation was noted in non-smokers (r= −0.4063, p = 0.0439) In general, the nutrient intake of smokers was equivalent or higher than that of non-smokers and was consistent with the Recommended Dietary Allowances (RDA) of the US. We conclude that cigarette smoking is pro-oxidant during pregnancy and that intake of antioxidant nutrients in amounts consistent with the RDA does not protect against this oxidant effect.
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