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

Liyuan Guo,Yumei Zhu,Honghui Zhao,Dongwei Mao,Chengjun Lin,Jianhua Che,Xiujuan Tian,Hong Zhu,Shiyu Han

doi:10.1038/srep13607

Abstract

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.

Highlights

Non-compliance of participants, and difference in the sensitivity of individuals to questions about vegetable or fruit intake, etc
Univariate analysis indicated that higher serum concentrations of α -carotene, β -carotene, vitamin E, and vitamin C were associated with lower risk of cervical cancer, but no significant association was observed for retinol (P-trend = 0.102)
Quartiles of dietary energy-adjusted antioxidant vitamin intakes of corresponding factors in the non-missing data, the associations between dietary or serum antioxidant vitamins and the risk of cervical cancer did not significantly change. In this hospital-based case-control study, we showed that higher serum concentrations of α -carotene, β -carotene, vitamin E, and vitamin C were associated with lower risk of cervical cancer in Chinese women

Summary

Introduction

Non-compliance of participants, and difference in the sensitivity of individuals to questions about vegetable or fruit intake, etc. A nested case-control study in the United States showed inverse associations between cervical cancer risk and serum α -carotene and β -carotene, but not retinol nor vitamins C and E9. Another nested case-control study in Finland and Sweden did not observe any associations between serum antioxidant vitamins and cervical cancer[8]. The main aim of this study was to evaluate the associations between serum antioxidant vitamin concentrations and risk of cervical cancer in a hospital-based case-control study of Chinese women. Our analyses included effect modification by passive-smoking status because smoking is an important modification factor for antioxidant status in vivo[12]

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