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- Chocolate (Theobroma cacao, Malvaceae)
- Vascular Function
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Date:
01-30-2015 | HC# 081432-513
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Re: Dark Chocolate Consumption for One Month Improves Vascular Function in Young, Healthy Subjects
Pereira
T, Maldonado J, Laranjeiro M, et al. Central arterial hemodynamic effects of
dark chocolate ingestion in young healthy people: a randomized and controlled
trial. Cardiol Res Pract. 2014;2014:945951. doi: 10.1155/2014/945951.
Ischaemic heart disease
and stroke are the most important causes of mortality worldwide. Studies have
shown that the severity of endothelial dysfunction relates to the risk for an
initial or recurrent cardiovascular event.1 Endothelial dysfunction
plays a critical role in the development of atherosclerosis, leading to
decreased arterial compliance. Nutrition is thought to affect endothelial
function. Foods rich in flavanols have been investigated for their role in
preventing cardiovascular disease. Cocoa (Theobroma
cacao, Malvaceae) and chocolate products have a high flavanol concentration
and antioxidant capacity. The authors conducted a randomized, controlled trial
to determine whether daily ingestion of a small amount of cocoa-rich chocolate
(>70%) improves the vascular function in young, healthy subjects.
Between
November 2012 and February 2013, 60 clinically healthy subjects (20 men and 40
women), all undergraduate students at the Superior Polytechnic Institute of
Coimbra, Portugal, were enrolled in the study. They were randomly allocated to
the control group (CG) or the intervention group (IG). The 30 subjects in the
CG were aged between 18 and 24 years; those in the IG, between 18 and 23 years.
The
first study evaluation was done at baseline, after which the subjects in the IG
ingested 10 g daily of dark chocolate with more than 75% cocoa for 1 month.
[Note: Source of chocolate and other information regarding chocolate contents
were not provided.] The CG had no intervention. A second evaluation was
conducted 1 week after the end of the 1-month intervention period.
Among
the clinical evaluations conducted were aortic pulse wave velocity (PWV),
central pulse wave analysis (PWA), brachial artery flow-mediated dilation (FMD),
augmentation index (AiX), distensibility index (ASI), blood pressure (BP),
heart rate (HR), and clinical observation.
Baseline
group characteristics were similar. The authors report no significant changes
during the trial in body mass index, HR, or brachial BP in either group,
although a consistent trend for reduced BP was seen in the IG.
Statistically
significant decreases in PWV (P=0.02) and ASI (P<0.01) were seen in the IG,
but not in the CG. A similar finding was also observed for the AiX, an indirect
measure of arterial stiffness. At baseline, no significant differences in FMD
were noted between the 2 groups; however, the FMD improved considerably after 1
month in the IG (P<0.001), with no significant changes in the CG. When
pooling the mean within-group individual differences for each group, the
authors reported a reduction in all variables after the 1-month intervention in
the IG, with statistically significant effects for ASI (P<0.001) and PWV
(P=0.010). Brachial and central BP levels also decreased in the IG.
To
summarize, vascular function significantly improved in young, healthy subjects who
consumed 10 g dark chocolate for 1 month.
The
probable mechanism for improved PWV, ASI, and AiX after cocoa consumption may
be the parietal relaxation of the large arteries, as well as a dilation of
small- and medium-sized peripheral arteries and arterioles, say the authors.
The "finding of improved FMD strongly suggests endothelium-dependent
vascular relaxation as the motive for the vasomotor benefit found," leading
to lower PWV, ASI, and AiX, and a trend toward reduced BP, write the authors.
"We
can suggest flavanol-containing cocoa as a promising and powerful option for
cardiovascular primary prevention."
—Shari Henson
Reference
1Widlansky ME, Gokce
N, Keaney JF Jr, Vita JA. The clinical implications of endothelial dysfunction.
J Am Coll Cardiol. 2003;42(7):1149-1160.
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