COLOSTRUM HAS NO EFFECT ON GROWTH FACTORS, AND ON A DOPING TEST

Abstract

Bovine colostrum is secreted during the first few days after calving and is a rich source of bioactive components, including insulin-like growth factor I (IGF-I), which may stimulate muscle protein synthesis. Several studies suggest that bovine colostrum ingestion may improve exercise performance. Since improvement in exercise performance was not paralleled by increased IGF-1 levels in the blood the mechanism of performance enhancement is unknown. Because IGF-1 is on the IOC doping list, it has to be clear whether athletes take any risk for a positive doping test when taking bovine colostrum. The aim of this study was twofold: to study the human growth hormone (hGH), IGF-1 levels and hematocrit in the blood before and after 4 weeks supplementation and to submit the urine to an official doping test. Nine healthy males took 60 gr/day bovine colostrum (Intact, Pro Performance) for 4 weeks. Blood and urine samples were collected just before starting supplementation and 4 weeks later. At week 4 blood was collected twice, after an overnight fast and 2 hours after taking the supplement. The doping test did not show any positive test. Mean hematocrit was 43.4% before, and 44.2% after 4 weeks (p = 0.31). IGF-1 before supplementation was 31.02 ± 13.25 nmol/l, and did not change after 4 weeks. HGH before supplementation, was 0.13 ± 0.08 μg/l and did not change either. Thus, bovine colostrum supplementation does not increase hGH and IGF-1 in the blood and does not yield a positive doping test.