Oral bovine colostrum supplementation does not increase circulating insulin-like growth factor-1 concentration in healthy adults: results from short- and long-term administration studies.
PURPOSE
Bovine colostrum is available in health food shops and as a sports food supplement and is rich in antibodies and growth factors including IGF-1. World Anti-Doping Agency advises athletes against taking colostrum for fear of causing increased plasma IGF-1. There are also concerns that colostrum may theoretically stimulate malignancy in organs which express IGF-1 receptors. We, therefore, determined changes in plasma IGF-1 levels in subjects taking colostrum or placebo for 1 day, 4 weeks, and 12 weeks.


METHODS
Plasma IGF1 levels were determined in healthy males (n = 16) who ingested 40 g bovine colostrum or placebo along with undertaking moderate exercise for total period of 4.5 h. Two further studies followed changes in IGF1 using double-blind, parallel group, placebo-controlled, randomized trials of colostrum or placebo (N = 10 per arm, 20 g/day for 4 weeks and N = 25 colostrum, N = 29 placebo arm 20 g/day for 12 weeks).


RESULTS
Baseline IGF1 levels 130 ± 36 ng/ml. 4.5 h protocol showed no effect of colostrum on plasma IGF1 (ANOVA, treatment group: p = 0.400, group × time: p = 0.498, time p = 0.602). Similarly, no effect of colostrum ingestion was seen following 4 week (ANOVA, group: p = 0.584, group × time interaction: p = 0.083, time p = 0.243) or 12 week (ANOVA, group: p = 0.400, group × time interaction: p = 0.498, time p = 0.602) protocol.


CONCLUSIONS
Ingestion of standard recommended doses of colostrum does not increase IGF-1 levels in healthy adults, providing additional support for the safety profile of colostrum ingestion.
['Davison|Glen|G|http://orcid.org/0000-0003-4340-0074', 'Jones|Arwel W|AW|http://orcid.org/0000-0003-1689-8065', 'Marchbank|Tania|T|http://orcid.org/0000-0003-2076-9098', 'Playford|Raymond J|RJ|http://orcid.org/0000-0003-1235-8504']
D000284:Administration, Oral D000328:Adult D000818:Animals D015415:Biomarkers D003126:Colostrum D019587:Dietary Supplements D006801:Humans D007334:Insulin-Like Growth Factor I D008297:Male D008892:Milk D012016:Reference Values
Food supplement Nutraceutical Prostate cancer Sports nutrition