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Ursprungligen postat av nikeplektrum
Haft en mailkonversation med henne i dag angående hennes senaste artikel i SvD om energidrycker.
Enligt henne är det absolut Taurin som ökar pulsen och är den aktiva ingrediensen i energidrycker, och alltså inte de 100-tals mg koffein man får i sig genom att dricka ett flertal.
Vafan
Hon är ju inte vetenskapsjournalist, men hon gör ju ett bra jobb:
Cardiovascular effects
While the primary goal of our study was to test how a
combination of caffeine and taurine impacted short term
memory, we found that ingestion of these drugs significantly
decreased heart rate an average of 8.1 beats=min
within 45 min. Mean arterial blood pressure also increased
but only after subjects took a memory test. Consumption
of caffeine increases cardioacceleratory signals, which
should increase heart rate (Suleman and Siddiqui,
1997–2004). Numerous studies, however, have shown that
caffeine consumption can cause heart rate to decline
through pressure-induced reflex bradycardia (Suleman
and Siddiqui, 1997–2004). Caffeine-induced heart rate
decline may also result from direct central vagal stimulation
(Whitsett et al., 1984). The caffeine dosage used in
our study (1.1–2.2 mg=kg) was lower than that used in
other studies (2.2–8.8 mg=kg), though the average heart
rate decline we observed was equal to or greater than that
seen previously (Pincomb et al., 1987, 1991; Robertson
et al., 1978; Suleman and Siddiqui, 1997–2004; Sung
et al., 1990; Whitsett et al., 1984). It may be that the taurine
facilitated pressure-induced reflex bradycardia, which
has been observed in rats (Yang and Lin, 1983). Further,
taurine has also been shown to increase cardiac stroke
volume (Baum and Weis, 2001), which would also
enhance pressure-induced reflex bradycardia.
After completing the memory assessment, test subject
mean arterial blood pressure (MABP3) was significantly
increased by an average of 2.8mmHg, and heart rate
began to return to resting levels but was still significantly
lower than them (Fig. 3). This might indicate that caffeine
and taurine in combination with a stressful event (such
as taking a test) elevate blood pressure and possibly heart
rate, likely in conjunction with catecholamine release
from the adrenal glands (Charmandari et al., 2005;
Robertson et al., 1978). The combination of caffeine
and psychological stress has been shown to increase blood
pressure (Pincomb et al., 1987).
http://dx.doi.org/10.1007/s00726-005-0302-x