Effect of lycopene supplementation on insulin-like growth factor-1 and insulin-like growth factor binding protein-3:: a double-blind, placebo-controlled trial

Objective: Studies have suggested a link between lycopene and insulin-like growth factor-1 ( IGF-1). The aim of this study was to test the effect of lycopene supplementation on IGF-1 and binding protein-3 ( IGFBP-3) status in healthy male volunteers. Design, setting, subjects and intervention: This was a 4 week randomized, double-blind, placebo-controlled study of lycopene supplementation ( 15 mg/day) in healthy male volunteers ( n = 20). Fasting blood samples were collected at baseline and after 4 weeks. Samples were analysed for lycopene by high-performance liquid chromatography ( HPLC) and IGF-1 and IGFBP-3 by enzyme-linked immunosorbent assay ( ELISA). Changes in end points from baseline were compared in those who received placebo versus those who received the lycopene supplement. Results: Median change in lycopene from baseline ( post-supplement - baseline) was higher in subjects in the intervention than those on placebo ( lycopene group 0.29 ( 0.09, 0.46); placebo group 0.03 ( - 0.11, 0.08) mu mol/l; median ( 25th, 75th percentiles), P < 0.01). There was no difference in median change in IGF-1 concentrations ( lycopene group -0.6 ( - 2.6, 1.9); placebo group - 1.15 ( - 2.88, 0.95) nmol/l, P = 0.52), or median change in IGFBP-3 concentrations ( lycopene group 245 ( - 109, 484); placebo group 101 ( - 34, 234) nmol/l, P = 0.55) between intervention and control groups. Change in lycopene concentration was associated with the change in IGFBP-3 in the intervention group ( r = 0.78; P = 0.008; n = 10). Conclusions: Lycopene supplementation in healthy male subjects has no effect on IGF-1 or IGFBP-3 concentrations in a healthy male population. However, the association between change in lycopene concentration and change in IGFBP-3 in the intervention group suggests a potential effect of lycopene supplementation on IGFBP-3. Sponsorship: University-funded.