A nested case-control study of dietary factors and the risk of incident cytological abnormalities of the cervix.
Several earlier case-control studies reported inverse associations of cervical squamous intraepithelial lesions (SIL) with high dietary or biomarker levels of carotenoids, folate, and vitamins C and E. However, most studies did not measure the primary causal factor, cancer-associated genital human papillomaviruses (HPV), now detected by sensitive viral DNA tests. This nested case-control study assessed whether high dietary intakes of these nutrients, plus zinc and vitamin A, reduced SIL risk in cancer-associated HPV DNA-positive women. Using a 60-item food-frequency questionnaire, nutrient estimates were obtained for 33 incident cases with high-grade lesions, 121 with low-grade lesions, 97 with equivocal SIL, and 806 cytologically normal controls sampled from a large prospective cohort study. Baseline cervicovaginal lavages were tested for HPV DNA by the polymerase chain reaction. Among DNA-positive cases (n = 68) and controls (n = 69), age-adjusted odds ratios (ORs) of SIL in the highest vs. the lowest nutrient quartiles were 1.4 [95% confidence interval (CI) = 0.5-4.2] for vitamin A, 0.6 (CI = 0.2-2.0) for beta-carotene, 1.3 (CI = 0.4-3.6) for vitamin C, 1.0 (CI = 0.4-3.6) for vitamin E, 0.7 (CI = 0.3-2.1) for folate, and 0.8 (CI = 0.3-2.2) for zinc. ORs in HPV DNA-negative women approximated 1.0, with the exception of vitamin E (OR = 0.5, CI = 0.3-0.9). These results do not support a protective role for the above nutrients against low-grade or equivocal SIL, which constituted the majority of diagnoses in this study.
Wideroff
L
L
Epidemiology and Biostatistics Program, National Cancer Institute, Bethesda, MD 20892, USA.
Potischman
N
N
Glass
A G
AG
Greer
C E
CE
Manos
M M
MM
Scott
D R
DR
Burk
R D
RD
Sherman
M E
ME
Wacholder
S
S
Schiffman
M
M
D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage; D002338:Carotenoids / Q000008:administration & dosage; D016022:Case-Control Studies; D002584:Cervix Uteri / Q000821:virology; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis*; D004032:Diet; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage; D006801:Humans; D027383:Papillomaviridae / Q000235:genetics*; D030361:Papillomavirus Infections; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012307:Risk Factors; D007507:Therapeutic Irrigation; D014412:Tumor Virus Infections; D014810:Vitamin E / Q000008:administration & dosage; D015032:Zinc / Q000008:administration & dosage; D002578:Uterine Cervical Dysplasia / Q000517:prevention & control* / Q000821:virology*
D004279:DNA, Viral; D014810:Vitamin E; D002338:Carotenoids; D005492:Folic Acid; D015032:Zinc; D001205:Ascorbic Acid