Associations between antioxidant vitamins and the risk of invasive cervical cancer in Chinese women: A case-control study.

Previous studies on the associations between dietary antioxidant vitamins and the risk of cervical cancer remain inconsistent, and little evidence is available for serum antioxidant vitamins, which provide more accurate measurements of these nutrients. We conducted a case-control study of 458 incident cases with invasive cervical cancer and 742 controls to assess the effects of diet or serum antioxidant vitamins. Higher serum antioxidant vitamins were associated with a lower risk of cervical cancer after adjusting for potential confounders. The odds ratios (ORs) for the highest (vs. lowest) quartile were 0.66 (95% confidence interval [CI] = 0.46-0.93; P = 0.024) for α-carotene, 0.63 (95% CI = 0.45-0.90; P = 0.006) for β-carotene, 0.53 (95% CI = 0.37-0.74; P < 0.001) for vitamin E, and 0.48 (95% CI = 0.33-0.69; P < 0.001) for vitamin C. Dietary intakes of vitamins E and C were inversely associated with the risk of cervical cancer. Risk of cervical cancer from serum antioxidant vitamins was more evident in passive smokers than non-passive smokers. These findings indicated that antioxidant vitamins (mainly α-carotene, β-carotene, and vitamins E and C) might be beneficial in reducing the risk of invasive cervical cancer in Chinese women, especially in passive smokers.