Associations between Dietary Intake of Fruits and Vegetables in Relation to Urinary Estrogen DNA Adduct Ratio

Background: Estrogen exposure plays a role in breast cancer (BC) development. A novel estrogen biomarker, the estrogen DNA adduct (EDA) ratio, was shown to be elevated in women at high-risk of BC and among BC cases. Modifiable factors may impact the EDA ratio, with studies demonstrating that resveratrol reduces EDA ratio in vitro. We sought to examine the hypothesis that dietary intake of fruits and vegetables is inversely associated with EDA ratio. Methods: This analysis was conducted in 53 pre-menopausal, healthy women aged 40 - 45 years from a cross-sectional study in which participants provided first-void urine samples and 3-day food records. Urine samples were analyzed using ultra performance liquid chromatography/tandem mass spectrometry. The EDA ratio was calculated as the estrogen-DNA adducts divided by estrogen metabolites and conjugates. A trend test was used to assess associations between tertiles of dietary intake using linear regression. Results: After adjustment for age, total energy, percent adiposity, serum estradiol and estrone-sulfate, we observed inverse associations of EDA ratio with carbohydrate consumption (P = 0.01) and vegetable intake (P = 0.01). EDA ratio was inversely associated with 5 botanical groups (Chenopodiaceae: P = 0.02;Umbelliferae: P = 0.03;Compositae: P = 0.01;Ericaceae: P = 0.01;Musaceae: P = 0.03) but not fruit intake overall. Conclusion: Although these data require replication before conclusions are drawn, this report suggests an inverse association between vegetable and carbohydrate consumption and EDA ratio. Impact: While more information is still needed, these findings suggest a link between dietary intake and a biomarker that is both associated with high-risk BC status and associated with modifiable factors.

Fruit intake associated with urinary estrogen metabolites in healthy premenopausal women

Urinary concentrations of 2:16-hydroxyestrone (2:16-OHE1) approximate concentrations of 2-OHE1 and 16α-OHE1 in breast tissue. As estrogens are purported to be involved in breast cancer development, the 2:16-OHE1 ratio can provide an indication of estrogen metabolite exposure in the breast. With prior studies observing associations between urinary estrogen metabolites and dietary intakeof fruits, vegetables, and fiberascertained from food questionnaires, we examined associations between dietary factors ascertained through 3-day food records and urinary 2:16-OHE1 in191 pre-menopausal healthy women. Fruit consumption was positively associated with 2:16-OHE1 after adjustment for total energy, ethnicity, body mass index, parity, smoking history, and serum estradiol (p = 0.003). Fruit consumption was positively associated with 2-OHE1 concentrations (p = 0.006), but was not associated with 16α-OHE1 (p = 0.92). The Musaceae botanical grouping (comprised primarily of bananas) was positively associated with the 2:16-OHE1 ratio, and Rosaceae (comprised of citrus fruits) and Musaceae botanical groupings were positively associated with 2-OHE1 (but not 16α-OHE1) concentrations, after adjustment for confounders. Our data suggest that dietary fruit intakeis associated with urinary 2-OHE1 and the 2:16-OHE1 ratio and that breast tissue exposure to estrogen metabolites may thus be influenced-by diet.