Heart-Healthy
Compound in Chocolate Identified
In a multifaceted study involving the Kuna
Indians of Panama, an international team of scientists has pinpointed a
chemical compound that is, in part, responsible, for the heart-healthy
benefits of certain cocoas and some chocolate products.
The researchers, who are from the University
of California, Davis; the Heinrich-Heine University of Duesseldorf, Germany;
and Harvard Medical School, hope the findings will lead to new dietary
or medicinal methods for improving and maintaining cardiovascular health.
The study showed that epicatechin, one
of a group of chemicals known as flavanols, was directly linked to improved
circulation and other hallmarks of cardiovascular health. Findings of the
study are reported in the Jan. 16 online issue of the Proceedings of the
National Academy of Sciences.
"Although previous studies strongly indicated
that some flavanol-rich foods, such as wine, tea and cocoa can offer cardiovascular
health benefits, we have been able to demonstrate a direct relationship
between the intake of certain flavanols present in cocoa, their absorption
into the circulation and their effects on cardiovascular function in humans,"
said UC Davis biochemist Hagen Schroeter, who co-authored the paper along
with cardiologist Christian Heiss of the Heinrich-Heine University.
"The results of this study provide direct
proof that epicatechin is, at least in part, responsible for the beneficial
vascular effects that are observed after the consumption of certain flavanol-rich
cocoas," Schroeter said.
Key to the study were volunteers from the
Kuna Indians, who live on the San Blas islands off the coast of Panama.
High blood pressure and other signs of cardiovascular disease are rare
among the island-dwelling Kuna, who are also known to consume large amounts
of flavanol-rich cocoa -- three to four cups per day. However, previous
studies carried out by Norman Hollenberg's research team at Harvard Medical
School have found that Kuna who have migrated to the suburbs of Panama
City on the mainland consume only about four cups of cocoa per week and,
interestingly, do not enjoy the same level of cardiovascular health.
Through analyses of urine samples from
members of both the island-dwelling and mainland Kuna, the researchers
found that, compared to their mainland counterparts, the urine of island
dwellers had more than twice the levels of urinary nitric oxide -- a chemical
compound already known to be associated with healthy flow of blood through
the arteries.
The Kuna project was only one part of a
five-pronged study approach that the research team conducted in order to
determine whether epicatechin meets five previously established criteria
for compounds that directly cause improved circulation. In the other four
parts of the study the researchers demonstrated that:
Levels of nitric oxide in the blood were
higher in individuals who drank flavanol-rich cocoa, compared to those
who drank cocoa beverages with low flavanol levels. This showed that flavanols
contained in the cocoa were actually absorbed and subsequently present
in the bloodstream.
Higher levels of the flavanol epicatechin
in the bloodstream were accompanied by improved blood flow.
In the laboratory, flavanols administered
to samples of vascular tissue caused the tissue to relax.
Pure epicatechin consumed by humans had
much the same effect as did consumption of flavanol-rich cocoa.
Considered together, these findings point
to epicatechin as one of the compounds found in cocoa that has beneficial
impacts on cardiovascular health.
Funding for this research was provided
by the Deutsche Forschungsgemeinschaft, Biomedicinisches Forschungszentrum
of the University of Duesseldorf and Mars Inc.
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