We evaluated tumor ER status and self-reported dietary intake in 142 women and plasma concentrations of carotenoids, retinol, and tocopherols in 149 women, at diagnosis of breast cancer, before any medical or surgical treatment. Overall odds of ER-positive status were decreased in relation to years of oral contraceptive use and preformed vitamin A intake. In the second study older women, women with higher plasma lutein concentration, and women not using beta-carotene supplements were more likely to be ER positive, when data were adjusted for body mass index and factors that may influence breast cancer risk or hormonal status. Significant independent relationships between plasma retinol or tocopherol concentrations and ER status were not observed. The strong and independent relationships between carotenoid intake, plasma lutein concentration, and ER status may relate to observations linking a carotenoid-rich diet with improved prognosis after diagnosis of breast cancer.
Data regarding carotenoids other than beta-carotene in relation to prostate cancer risk are sparse.
We concluded a prospective cohort study to examine the relationship between the intake of various carotenoids, retinol, fruits, and vegetables and the risk of prostate cancer. All P values resulted from two-sided tests. No consistent association was observed for dietary retinol and risk of prostate cancer. These findings suggest that intake of lycopene or other compounds in tomatoes may reduce prostate cancer risk, but other measured carotenoids are unrelated to risk. Our findings support recommendations to increase vegetable and fruit consumption to reduce cancer incidence but suggest that tomato-based foods may be especially beneficial regarding prostate cancer risk.