The role of beta-carotene and other dietary factors in the aetiology of cervical dysplasia: results of a case-control study.

The effects of beta-carotene and several other dietary factors on the risk of cervical dysplasia were evaluated in a case-control study. Cases (n = 257) were the participants of a randomized trial assessing the effect of beta-carotene on cervical dysplasia. Controls (n = 705) were sampled from the general population. A postal questionnaire was used to obtain information about the frequency of consumption of several food items containing beta-carotene, retinol, vitamin C and dietary fibre. Information was also collected about other risk factors for cervical dysplasia, in order to adjust for possible confounding. To our surprise, we observed an increased risk of cervical dysplasia for women with a high intake of beta-carotene (odds ratio (OR) = 2.31; 95% confidence interval (CI): 1.27-4.19). No relationship was found with the intake of retinol, while both vitamin C and dietary fibre showed a weak and not statistically significant inverse relationship with cervical dysplasia. These findings do not support the hypothesis that beta-carotene protects against cervical dysplasia.