Relation of insulin-like growth factor (IGF) I and IGF-binding protein 3 concentrations with intakes of fruit, vegetables, and antioxidants

Relation of insulin-like growth factor (IGF) I and IGF-binding protein 3 concentrations with intakes of fruit, vegetables, and antioxidants 1,2,3 Cong Dung Tran, Caroline Diorio, Sylvie B\ue9rub\ue9, Michael Pollak and Jacques Brisson 1 From the D\ue9partement de m\ue9decine sociale et pr\ue9ventive, Universit\ue9 Laval, Quebec, Canada (CDT, CD, and JB); Unit\ue9 de recherche en sant\ue9 des populations (CDT, CD, SB and JB) and Centre des maladies du sein Desch\ueanes-Fabia (SB and JB), H\uf4pital du St-Sacrement du Centre hospitalier affili\ue9 universitaire de Qu\ue9bec, Canada; and the Departments of Medecine and Oncology, Cancer Prevention Research Unit, Lady Davis Institute of the Jewish General Hospital and McGill University, Montreal, Canada (MP) Background: Fruit, vegetable, and antioxidant intakes may reduce the risk of several insulin-like growth factor (IGF)\u96related chronic diseases, such as certain types of cancers and cardiovascular diseases. Objective: This study investigated whether intakes of fruit, vegetables, and antioxidants ( f-carotene, lycopene, and vitamin C) are associated with plasma IGF-I and IGF-binding protein 3 (IGFBP-3) concentrations. Design: Plasma IGF-I and IGFBP-3 concentrations were measured in 1542 healthy women by enzyme-linked immunosorbent assay. A self-administered semiquantitative food-frequency questionnaire was used to estimate mean daily dietary intakes of fruit, vegetables, and antioxidants over the year preceding blood sampling. Multivariate analyses were performed by using generalized linear models to evaluate the association of quintiles of daily intakes with concentrations of growth factors. Results: A higher intake of citrus fruit was associated with higher concentrations of IGF-I (215 ng/mL for quintile 5 compared with 205 ng/mL for quintile 1; P for trend =3D 0.04) and with lower concentrations of IGFBP-3 (4803 ng/mL for quintile 5 compared with 4960 ng/mL for quintile 1; P for trend =3D 0.04). Higher dietary vitamin C intake was associated with higher concentrations of IGF-I (214 ng/mL for quintile 5 compared with 204 ng/mL for quintile 1; P for trend =3D 0.02) and lower concentrations of IGFBP-3 (4813 ng/mL for quintile 5 compared with 4953 ng/mL for quintile 1; P for trend =3D 0.03). Total intake of fruit and vegetables and intakes of other botanical fruit and vegetable subgroups, f-carotene, and lycopene were not related to either IGF-I or IGFBP-3 concentrations. Conclusion: Women with higher intakes of citrus fruit or dietary vitamin C tend to have higher plasma concentrations of IGF-I and lower plasma concentrations of IGFBP-3. Key Words: Diet \u95 fruit \u95 vegetables \u95 antioxidants \u95 nutrients \u95 insulin-like growth factor \u95 insulin-like growth factor binding protei