American Indian women in the Southwest have high rates of cervical dysplasia and cervical cancer but low rates of cancer at other sites (119). A pilot case-control study in this population evaluated the relationship between cytological abnormalities and dietary intake of various micronutrients. Forty-two women with cervical dysplasia and 58 with normal cytology provided 24-h dietary recall information. Although no differences between case-subjects and controls were statistically significant, women whose intake of vitamin C, vitamin E or folacin was low were at higher risk for cervical dysplasia. Whereas many epidemiological investigations suggest a protective role for dietary vitamin A, β-carotene, or other carotenoids, a study in the  etiology of cervical dysplasia (120). Subjects were 257 women with cervical dysplasia and 705 population controls who were thought to be free of dysplasia but were not examined cytologically when they entered the study. Information on diet and other risk factors was obtained by postal questionnaire. There was no indication that β-carotene protects against development of cervical dysplasia. In fact, there was a slightly higher risk of dysplasia in women with the highest intake of β-carotene protects against development of cervical dysplasia. In fact, there was a slightly higher intake of β-carotene. Nor could a relationship be shown with dietary retinol. Fiber and vitamin C were weakly but nonsignificantly protective.

A case- control study at major cancer treatment centers in Costa Rica, Panama, Mexico City, and Bogota, Colombia investigated dietary (121) and serological (112) indicators of risk for invasive cervical cancer. After adjustment for confounding factors, women in the highest quartiles of fruit and fruit juice consumption were at slightly lower risk. Vegetables, foods of animal origin, folacin-rich food, complex carbohydrates, and legumes were not associate with risk. Based on nutrient indices, significant trends of decreasing risk were found for vitamin C, β-carotene, and other carotenoids. However, adjustment  for vitamin C intake attenuated the effect of  β-carotene. For cancer patients, serologic investigations were restricted to those with stage I and II disease, to minimize the effects of disease on serum markers. Case-patients and controls did not differ significantly in serum levels of retinal, cryptozanthin, lycopene, α-carotene, lutein, or α-tocopherol. The mean level of β-carotene was some what lower in cancer patients; that of γ- tocopherol might represent an alteration caused by the disease process, but no evidence for a disease effect was seen for the other markers. The general concordance between dietary and serum data suggests that β-carotene has a protective role in the etiology of cervical cancer and demonstrates the discriminatory indicators.