JAMA 7/4/07 - Maybe some wizard medicine applies to muggles as well… An article in JAMA by Taubert et al. tests the theory that flavonols found in dark chocolate may lower blood pressure.
The study population consisted of 44 otherwise healthy subjects with upper-range prehypertension or stage 1 hypertension. Patients with any other major medical problems including CVD, diabetes, hyperlipidemia, etc were excluded. Study design was an RCT with investigators blinded, but subjects not – because they couldnt disguise the white and the dark chocolate. Patients were also counseled to abstain from any other cocoa products during the study. Participants were instructed to take one 5.6(white) or 6.3(dark) gram piece of chocolate per day.
At 6 weeks – no statistical difference between groups.
12 weeks: dark chocolate group BP was down 2.4/1.3 mmHg from baseline.
At 18 weeks the BP difference in the dark chocolate group was – 2.9/1.9 mmHg.
The white chocolate group: no change.
Looks like we have a winner.
For the basic science portion of the study, researchers measured plasma S-nitrosoglutathione. Basically they postulate that this compound is an intermediary between nitric oxide stores and active NO in the endothelium. They also measured 8-isoprostane, a measure of oxidative stress. Levels of S-nitrosoglutathione were significantly increased only in the dark chocolate group. 8-isoprostane levels were unchanged with intervention in both groups. Investigators concluded that the effect of dark chocolate was more likley from stimulation of endothelial NO production rather than changes in redox equilibrium between thiol and nitrosothiols. Big words aside – it seemed to work… at least in a healthy, homogenous, untreated population with mild HTN – although I dont seem to have alot of those in my practice….
