geht ja auch eher um die unterdrückung der hormonproduktion....
Zitat:
Growth Hormone
The deleterious effects of ethanol on humans and animals is consistent and well-established in both adults and adolescents, with decreases in GH levels, GH mRNA (24), as well as GH releasing factor mRNA levels (25). In adolescent rats, administration of 3g/kg of ethanol, which, due to the faster metabolism of rats produced blood alcohol levels equivalent to only about 4-6 drinks for humans, caused a massive drop in GH levels to just 4-7% of control by the 1.5 hour mark (26) -- Levels were still down 66-86% after 24 hours. In adult rats, the same 3g/kg caused total suppression of GH release, with 2g/kg causing significant but not total suppression (27).
In young adult male humans, 1.5mg/kg disrupted the nocturnal rhythm of GH secretion in all subjects, as well as decreasing overall release by 30% (28).
Zitat:
Let's now turn to some studies that looked directly at testosterone levels following acute alcohol administration. In adult males, 1.3g/kg of ethanol (about 10 drinks for a 200 lb person), caused a significant decrease vs. basal levels at the 60 minute mark. Differences for the next two hours were not significant, though the researches did not utilize a control group, so the natural morning rise in testosterone could have masked any effects (38). 1.5g/kg lowered levels by an average of 23% over a 24 hour period (28). 1.75g/kg lowered levels by 27% and 16% at 12 and 24 hours, respectively (34). Adolescent males admitted to the hospital for alcohol intoxication were found to have 21% lower testosterone levels than controls (36).
A couple of studies have looked at alcohol and exercise. 1.5g/kg depressed testosterone by more than 20% by 1 hour and was still depressed by the same margin at hour 10 (37). Interestingly, when the same ethanol dose was preceded by an exercise session, the suppressive effect continued for 22 hours -- and when exercise was performed during a hangover, significant suppression (21-32%) vs. ethanol alone continued for 26 hours. Compared to control, both ethanol groups had significantly lower testosterone levels for 42 hours - this is almost 2 full days. A much smaller intake (.83g/kg) did not result in a significant decrease (35).
All of this is at what are fairly moderate doses. Let's take a look at binge drinking doses.
Probably for ethical reasons, doses equating to 20+ drinks have not been studied in humans, so we must settle for rat data, but considering the effects at lower doses seem quite similar, these studies are likely quite relevant -- and could actually underestimate the effect, since, as we mentioned, these doses resulted in much lower blood alcohol levels in rats than humans.
3g/kg caused massive suppression of testosterone (67). Between hours 1.5 and 96 (yes, 4 days later), testosterone was reduced between 50-75% and, even a full week later, it was still down 40%. By week two, it was finally back to control level.
Zitat:
Protein Synthesis
Both ethanol and its metabolic byproduct, aldehyde, have been shown to reduce protein synthesis in skeletal muscle (85, 86, 87, 88). To make matters worse, it is predominately Type II, fast-twitch fibers that are affected, with type IIB being hit the hardest (85, 86, 87). This is not a good thing for bodybuilders, and it is a very bad thing for athletes.
With acute administration of real-world doses (.8 - 2.0g/kg) of ethanol, reductions in protein synthesis of 20-30% have been seen within about o*ne to two hours of administration, this is before the previously reviewed hormonal changes occur, indicating that alcohol is exerting a direct effect (85, 86, 88). Within 24 hours, decreases of as high as 63% have been shown to occur (86), which likely reflects the added contribution of negative hormonal changes.
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