Misschien zullen er een aantal al van op de hoogte zijn, maar ik denk dat velen dit niet weten. Ik heb er even snel twee studies uitgepikt:
Bron: Inheritable stimulatory effects of caffeine on steroidogenic acute regulatory protein expression and cortisol production in human adrenocortical cells
Bron: Caffeinated coffee does not acutely affect energy intake, appetite, or inflammation but prevents serum cortisol concentrations from falling in healthy men
In mensentaal: cafeïne stimuleert de aanmaak van cortisol, het stresshormoon dat onder andere verantwoordelijk is voor de afbraak van eiwitten. Cortisol is spierafbrekend. Ik kan me voorstellen dat mensen die de hele dag door koffie drinken, hiermee nadeel zullen ondervinden bij het opbouwen en behouden van spieren. Kappen dus met die koffie! Iemand die opmerkingen heeft over deze bevindingen (m.b.t. bodybuilding)?
Citaat:
|
Caffeine is the most widely consumed psychoactive substance in the world. It can elevate the level of glucocorticoid which is involved in metabolism regulation, stress response, and immune function. However, the specific mechanism has yet to be elucidated. Glucocorticoid is steroid hormone synthesized in adrenal cortex and the key rate-limiting step in its biosynthesis is mediated by steroidogenic acute regulatory protein (StAR). This study was designed to investigate the direct effects and inheritable epigenetic mechanisms of caffeine on cortisol production and StAR expression in human adrenocortical cells. The human adrenocortical cell line NCI-H295A was cultured with 0.4-40μM caffeine. There was a significant increase of the cortisol production in cells. In both acutely and chronically caffeine-treated cell groups, mRNA and protein expressions of StAR were stimulated in a dose-dependent manner. DNA methylation detection via bisulfite-sequencing PCR (BSP) uncovered a single site CpG demethylation at nt -682 within the StAR promoter region. Then we investigated how long the increased StAR expression and the single CpG demethylation could last. The caffeine was withdrawn after 48h of treatment and then the cells were continually subcultured for up to 5 and 10 passages, respectively. The results showed that the StAR expression at post-caffeine passage 10 still increased, as compared with that in the control. The caffeine-induced demethylation at nt -682 in StAR promoter underwent a similar time course as StAR expression does. The present study reveals the direct effect and possible inheritable epigenetic mechanism of caffeine on steroidogenesis in human adrenocortical cells and has implications for our understanding of the consumption of caffeine. |
Citaat:
|
Our aim in this crossover study was to investigate the acute effects of caffeinated and decaffeinated coffee consumption on appetite feelings, energy intake, and appetite-, inflammation-, stress-, and glucose metabolism-related markers. Sixteen healthy men (age range, 21-39 y; BMI range, 19.7-28.6 kg/m(2)) received in a random order on 3 separate occasions a standard breakfast snack with 200 mL of either caffeinated coffee (3 mg caffeine/kg body weight), decaffeinated coffee, or water (control). Before intervention (-15 min) and at standard time points following breakfast consumption (0, 15, 30, 60, 90, 120, 150, and 180 min), participants recorded their appetite feelings and we collected blood samples for measurements of circulating glucose, insulin, cortisol, and appetite- and inflammation-related markers. At 180 min, participants consumed a meal ad libitum. The appetite-related ratings, the appetite plasma hormonal responses as well as the plasma glucose, serum insulin, and plasma and serum inflammatory marker responses did not show an overall intervention effect or a time x intervention interaction. Ad libitum energy intake did not differ among the 3 interventions. However, a significant intervention effect (P = 0.04) and a time x intervention interaction (P-interaction = 0.02) were found for serum cortisol; cortisol concentrations were significantly higher following the caffeinated coffee intervention, compared to control, at 60 min and thereafter. In conclusion, the usually consumed amount of caffeinated coffee does not have short-term effects on appetite, energy intake, glucose metabolism, and inflammatory markers, but it increases circulating cortisol concentrations in healthy men. |
In mensentaal: cafeïne stimuleert de aanmaak van cortisol, het stresshormoon dat onder andere verantwoordelijk is voor de afbraak van eiwitten. Cortisol is spierafbrekend. Ik kan me voorstellen dat mensen die de hele dag door koffie drinken, hiermee nadeel zullen ondervinden bij het opbouwen en behouden van spieren. Kappen dus met die koffie! Iemand die opmerkingen heeft over deze bevindingen (m.b.t. bodybuilding)?