The effects of dietary protein on the somatotropic axis: a comparison of soy, gelatin, α-lactalbumin and milk

Abstract

Background/Objectives: Growth hormone (GH) is an important regulator of growth and body composition. It has been shown that GH release can be promoted by administration of various amino acids (AAs), such as arginine and lysine, that are present in soy protein. We previously showed that oral ingestion of soy protein stimulates the GH release, it is not known however to which extent other proteins stimulate the GH secretion. Subjects/Methods: Ingestion of soy protein (soy), gelatin protein (gelatin), a-lactalbumin protein (a-lactalbumin) and milk protein (milk) were compared on their GH-stimulating capacity. After oral ingestion of protein (0.6 g protein per kg bodyweight), blood was sampled every 20 min for 5 h to analyze GH, AA, insulin and glucose concentrations. The study was performed in eight healthy women (aged 19-26 years; body mass index 19-26 kg/m 2 ) in a randomized, single blind, placebocontrolled crossover design. Results: GH responses were more increased after ingestion of gelatine (8.2 ± 1.1 mg/l) compared with ingestion of soy, a-lactalbumin and milk (5.0±0.8, 4.5±0.6 and 6.4±1.0 mg/l, respectively) (Po0.05). After ingestion of each protein, GH responses were higher compared with placebo ingestion (Po0.05). Simultaneously ingestion of gelatin resulted in the highest serum-arginine concentrations (ARG) compared with after ingestion of the other proteins (Po0.05). Insulin as well as glucose concentrations were not different after ingestion of the various proteins (Po0.05). Conclusions: The GH-promoting activity of protein depends on the protein source, in that, gelatin protein is the most potent GH stimulator. Arginine may be the responsible AA in the GH-promoting effect of gelatin, although each protein may have its own specific AA-spectrum involved in the stimulation of the somatotropic axis.

The association of macro- and micronutrient intake with growth hormone secretion

“…While van Vught et al have performed detailed studies evaluating the contribution of protein intake on acute GH stimulation 5, 6 , limited studies have evaluated the role of macronutrient intake in long-term GH regulation. An earlier study in 35 elderly subjects was not able to detect any association between macronutrient intake and morning GH.…”

“…Endogenous and stimulated GH secretion are reduced in the context of generalized and excess visceral adiposity 1–3 and are known to be enhanced by fasting 4 . Furthermore, protein intake, in particular gelatin, can acutely increase GH secretion in the short term 5,6 . However, the long-term contribution of various macro- and micronutrients on GH secretion has not been comprehensively investigated.…”

Associations of types of dairy consumption with adiposity: cross-sectional findings from over 12 000 adults in the Fenland Study, UK

“…Dairy products and mainly milk have been consistently associated with bone health due to their nutrients content including calcium, phosphorous, vitamin D and protein, which might partly explain the positive association with lean mass(37). Another potential mechanism is the increasing effect of milk on growth hormone(38, 39), which has been associated with a higher lean mass through a higher bone mineral density and muscle mass(40).…”

MicroRNA-21-Enriched Exosomes as Epigenetic Regulators in Melanomagenesis and Melanoma Progression: The Impact of Western Lifestyle Factors

“…This is of concern because height at ages 7–13 years significantly increases MM risk [ 209 ]. Elevated GH plasma levels have also been observed after ingestion of gelatin protein, soy protein, and α-lactalbumin, a whey protein [ 303 ]. Of notice, recombinant GH is frequently abused in combination with androgens and whey protein supplements to gain muscle mass [ 304 ], a doping procedure that may increase MM risk.…”