Fruit and vegetable intake influences the association between exposure to polycyclic aromatic hydrocarbons and a marker of oxidative stress in pregnant women.

Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy is known to increase oxidative stress, which may influence pregnancy outcomes and health of the child. This study investigated whether fruit and vegetable intake modifies the relationship between exposure to PAHs and oxidative stress status during pregnancy. Urinary levels of 2-naphthol and 1-hydroxypyrene (biomarkers of exposure to PAHs), and malondialdehyde (MDA; a biomarker of oxidative stress) were analyzed in 715 pregnant women at 12-28 weeks of gestation. The dietary antioxidant intake during pregnancy was estimated using the 24-h recall method. Urinary 2-naphthol, 1-hydroxypyrene and MDA levels were analyzed by high-performance liquid chromatography-fluorescence detection. The urinary MDA level was positively correlated with the 2-naphthol level (r=0.255, P<0.001) and 1-hydroxypyrene level (r=0.240, P<0.001). Multiple regression analysis after adjustment for covariates revealed that the urinary 1-hydroxypyrene level was positively associated with the MDA level; these positive associations only existed in pregnant women, with either the fruit and vegetable intake or the vitamin C intake in the first tertile (<390.1 g/day) or in the first and second tertiles (<141.5 mg/day), respectively. These results suggest that an adequate maternal intake of fruit, vegetables and vitamin C is beneficial to the defense against the oxidative stress associated with exposure to PAHs in pregnant women.