Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flavanols key to potential chocolate benefits

29.09.2005


Flavanol-rich cocoa drink improved blood vessel function in smokers.



Phytochemicals known as flavanols, which are found in chocolate, fruits and vegetables, can boost the levels of nitric oxide in the blood of smokers and reverse some of their smoking-related impairment in blood vessel function, according to a new study in the Oct. 4, 2005, issue of the Journal of the American College of Cardiology.

"While the long-term benefits of such improvements remain to be established, we believe that one exciting outcome of this study is the demonstration that flavanol-rich cocoa can significantly improve an important marker of cardiovascular health in a population with an established cardiovascular risk factor. This raises the possibility that a potential new agent for the prevention and/or treatment of cardiovascular disease may emerge from additional research," said Malte Kelm, M.D. from the Heinrich-Heine-University in Duesseldorf, Germany.


The researchers studied smokers because their blood vessels tend to respond poorly to changes in blood flow, possibly related to impairments in how nitric oxide sends signals to the inner lining, the endothelium, of blood vessels. This impaired endothelial function is a marker for increased risk of cardiovascular disease.

A dozen smokers (six men and six women) in their early 30s, who did not have any known health problems, were enrolled in the double-blind crossover study to compare the effects of a cocoa drink rich in flavanols to a cocoa drink that tasted the same, but contained very low levels of flavanols. One woman was excluded from the analysis because she had high cholesterol levels. Circulating nitric oxide levels and blood vessel responses (flow-mediated dilation) were measured before drinking the cocoa and again two hours later. Each participant drank flavanol-rich and flavanol-poor cocoa drinks during different testing sessions.

There were significant increases in circulating nitric oxide and flow-mediated dilation after ingestion of drinks containing 176 to 185 milligrams of flavanols, a dose potentially exerting maximal effects. These changes correlated with increases in flavanol metabolites. In addition, the improvements were reversed when the participants were given a drug (L-NMMA) that interferes with nitric oxide signaling, thus supporting the idea that the flavanol-rich cocoa drink produced its effects by influencing the nitric oxide system.

"Taken together, these findings support the notion that flavanol-rich foods, including cocoa products, may help to promote cardiovascular health," Dr. Kelm said.

However, he said the main point of the study was to identify the active ingredients so that they can be studied further. The researchers pointed out that the cocoa drink they used was specially processed to retain much higher levels of flavanols than are typically found in commercially-available cocoa drinks; so it is unlikely that drinking more hot chocolate would produce a similar effect.

Even though this study involved only 11 participants, lead author Christian Heiss, M.D., Ph.D., pointed out that the results were in agreement with other studies indicating potential benefits from flavanol-rich foods, including cocoa and chocolate.

"Therefore, we feel that there exists an increasing body of evidence for an acute effect of flavanol-rich foods on vascular reactivity. Nevertheless, the conclusion drawn from these results have to be interpreted with caution, because it is not known whether or not the chronic consumption of flavanol-rich foods leads to sustained increases in endothelial function, and the prevention of future cardiovascular events. In particular in smokers, it is unlikely that cocoa can completely attenuate the deleterious effects of continued smoking," Dr. Heiss said.

Dr. Heiss is currently affiliated with the Division of Cardiology, University of California in San Francisco, California.

The researchers emphasized that this study was not designed to investigate whether flavanols could protect smokers; smokers were enrolled because they tend to have abnormal blood vessel responses.

Mary B. Engler, Ph.D., who is also at the University of California in San Francisco, but was not connected with this study, noted that it is the first such study in smokers to demonstrate that endothelial function improved after drinking cocoa with high levels of flavonoids.

"The study has helped to identify the optimal concentrations, potential mechanisms and the role of biologically active metabolites of the cocoa flavonoids in the improvement in vascular function in smokers. Although, it is a small study with 11 subjects, it has important implications and further supports the current evidence on the heart-healthy benefits of dark chocolate and drinks rich in cocoa flavonoids. Larger, long-term studies are definitely needed in follow-up," Dr. Engler said.

Dr. Engler emphasized that quitting smoking is the best way to reduce heart disease risk. She also pointed out that many foods and beverages contain a substantial amount of the same flavonoids (flavanols-epicatechin, catechin) found in cocoa and dark chocolate. These foods include green and black tea (especially Ceylon tea), red wine, sweet cherries, apples, apricots, purple grapes, blackberries, raspberries and broad beans.

Professor Gerd Heusch, M.D., at the Universitätsklinikum Essen in Essen, Germany, who also was not connected to this research effort, said the study indicates that flavonoids have an effect on the same nitric oxide system that is damaged by smoking.

"A flavanol- rich drink is capable of increasing nitric oxide levels in the blood and reversing the detrimental effect of smoking on vascular adaptation. It remains to be seen whether the acute beneficial effect of a flavanol-rich drink translates into a long-term benefit, in terms of attenuating or preventing the development of atherosclerosis," Dr. Heusch said.

Amy Murphy | EurekAlert!
Further information:
http://www.acc.org

More articles from Life Sciences:

nachricht Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>