Nutrition and Metabolic Insights

Background: Several isolated ingredients have been proposed to increase growth hormone (GH) release, including Chlorophytum borivilianum and Velvet bean. A combination of these two ingredients has been packaged within an investigational dietary supplement. It was the purpose of the present investigation to determine the impact of acute ingestion of this supplement on circulating GH in healthy, exercise-trained men.

Methods: Fifteen men ingested the dietary supplement on two different days, separated by one week. Blood was collected from subjects before ingestion of the supplement and at 20, 40, 60, 80, 100, and 120 minutes post ingestion. GH was analyzed in serum samples using an ELISA method. Values for GH for each subject, at each collection time, were averaged over both test days and used in the main analysis.

Results: Serum GH increased over time, with higher values at 60 minutes (1.56 ± 0.65 ng • mL-1; P = 0.04; +767%), 80 minutes (1.76 ± 0.69 ng • mL-1; P = 0.02; +878%), and 100 minutes (1.48 ± 0.62 ng • mL-1; P = 0.05; +722%) compared to pre ingestion (0.18 ± 0.04 ng • mL-1). A great deal of subject variability existed in the area under the curve (AUC) for GH, with pooled values ranging from 0.49 to 61.2 ng • mL-1 • 2 hr-1.

Conclusion: Acute ingestion of an investigational dietary supplement containing the active ingredients Chlorophytum borivilianum and Velvet bean results in an increase in circulating GH in exercise-trained men. Additional placebo controlled investigations are needed to extend these findings. Moreover, studies are needed to determine if chronic use of such supplementation leads to favorable changes in health-related parameters associated with increased circulating GH.