Effect of lycopene supplementation on insulin-like growth factor-1 and insulin-like growth factor binding protein-3:...

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.

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) micromol/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).

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.