from the ACS News Service
Study finds that people are programmed to love chocolate
Journal of Proteome Research
WASHINGTON, Oct. 12, 2007 — For the first time, scientists have linked the all-too-human preference for a food — chocolate — to a specific, chemical signature that may be programmed into the metabolic system and is detectable by laboratory tests. The signature reads ‘chocolate lover’ in some people and indifference to the popular sweet in others, the researchers say.
The study by Swiss and British scientists breaks new ground in a rapidly emerging field that may eventually classify individuals on the basis of their metabolic type, or metabotype, which can ultimately be used to design healthier diets that are customized to an individual’s needs. The study is scheduled for publication in the Nov. 2 issue of American Chemical Society’s Journal of Proteome Research, a monthly publication.
Sunil Kochhar and colleagues studied 11 volunteers who classified themselves as ‘chocolate desiring’ and 11 volunteers who were ‘chocolate indifferent.’ In a controlled clinical study, each subject — all men — ate chocolate or placebo over a five day period while their blood and urine samples were analyzed. The ‘chocolate lovers’ had a hallmark metabolic profile that involved low levels of LDL-cholesterol (so-called ‘bad’ cholesterol) and marginally elevated levels of albumin, a beneficial protein, the scientists say.
The chocolate lovers expressed this profile even when they ate no chocolate, the researchers note. The activity of the gut microbes in the chocolate lovers was also distinctively different from the other subjects, they add.
“Our study shows that food preferences, including chocolate, might be programmed or imprinted into our metabolic system in such a way that the body becomes attuned to a particular diet,” says Kochhar, a scientist with Nestlé Research Center in Switzerland.
“We know that some people can eat a diet that is high in steak and carbs and generally remain healthy, while the same food in others is unhealthy,” he explains. “Knowing one’s metabolic profile could open-the-door to dietary or nutritional interventions that are customized to your type so that your metabolism can be nudged to a healthier status.”
Researchers have known for some time that metabolic status and food preferences can vary from person to person and even between different cultures. The recent growth of the new field of proteome research, which focuses on characterizing the structure and function of the complete set of proteins produced by our genes, has allowed scientists to gain a deeper understanding of the metabolic changes that occur when foods are digested, Kochhar says.
“There’s a lot of information in metabolism that can be used to improve health and this information is just now being explored and tapped,” the researcher says.
In the future, a test for determining one’s metabolic type could be performed as part of a blood or urine test during a regular visit to the doctor, Kochhar predicts. But a reliable test to measure one’s metabolic type may be five years away, as more research is still needed in this area, he notes.
Women were not included in the current study in order to avoid any metabolic variations linked to the menstrual cycle, which has been shown in studies by others to influence metabolic differences, Kochhar says. But the researchers plan to include women in future clinical trials on metabolic responses to chocolate to determine if there is a gender-specific response to the treat.
In addition to providing a better understanding of individual metabolic types, the current study could also lead to the discovery of additional biomarkers that can identify new health benefits linked to chocolate and other foods, says Kochhar, whose research was funded by Nestlé.
The American Chemical Society — the world’s largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
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New process boosts levels of heart-healthy compounds in cocoa powder
Journal of Agricultural and Food Chemistry
Scientists in Spain are reporting development of a new process to make cocoa powder with higher amounts of the healthful chemical compounds linked to chocolate’s beneficial effects. The study was published in the May 30, 2007, issue of ACS’ Journal of Agricultural and Food Chemistry.
Juan Carlos Espin de Gea and colleagues report that the new cocoa powder contains levels of some flavonoids 8 times higher than conventional cocoa. They achieved the higher flavonoid content by omitting the traditional fermentation and roasting steps used in the processing of cocoa beans. Those steps destroy some flavonoids, which are natural antioxidants.
Researchers used the flavonoid-enriched cocoa powder in a clinical trial to determine whether the compounds were bioavailable — in a form that humans can absorb. In the trial, six healthy volunteers consumed a milk drink made with flavonoid-enriched cocoa. The same volunteers later drank chocolate milk made from traditional cocoa. Blood and urine tests established the bioavailability of flavonoids in the enriched-milk drink, showing that people do absorb higher levels of the compounds. Based on the results, researchers suggest further clinical trials on the health benefits of flavonoid-enriched cocoa powder.
“A New Process to develop a Cocoa Powder with Higher Flavonoid Monomer Content and Enhanced Bioavailability in Healthy Humans”
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CONTACT:
Juan Carlos Espin de Gea, Ph.D.
Centro de Edafología y Biología Aplicada del Segura (CEBAS) - CSIC
Murcia, Spain
Phone: 34-968-396344
Fax: 34-968-396213
Email: [email protected] <mailto:[email protected]
Most Comprehensive-Ever Survey of Flavonoids in U. S. Foods
Journal of Agricultural and Food Chemistry
Scientists studying the health benefits of flavonoids — those disease-preventing compounds in fruits, vegetables, wine, dark chocolate and other foods — finally have comprehensive data on flavonoid levels in foods consumers buy in the United States. The U. S. Department of Agriculture’s James M. Harnly and colleagues are unveiling new flavonoid data collected from the first systematic sampling of foods designed specifically to characterize flavonoids. The report appeared in the Jan. 10, 2007, issue of the ACS’ Journal of Agricultural and Food Chemistry, a bi-weekly publication.
The report notes that interest in the flavonoid content of foods dates to the early 1980s. Since then, two databases had been compiled on levels of these compounds in common foods; the first based on a critical evaluation of flavonoid data in the literature and the second based on the analysis of proanthocyanidins found in selected foods. The reported data have been combined with the literature database.
For the latest report, researchers determined levels of 20 flavonoids in more than 60 fresh fruits, vegetables and nuts collected at two different times of the year from commercial markets in four regions of the United States. Researchers analyzed an average of five samples for each food. Complete results are included in the article. They found flavonoid levels that compared well with the literature database, but the catechins were generally lower in fruits and nuts than the figures reported in the proanthocyanidin database. The new study found a high variability in the flavonoid content of food samples.
“Flavonoid Content of U. S. Fruits, Vegetables, and Nuts”
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CONTACT:
James M. Harnly, Ph.D.
U. S. Department of Agriculture
Agricultural Research Service
Beltsville, Maryland
Phone: 301-504-8569 ext. 261
Fax: 301-504-8314
Email: [email protected] <mailto:[email protected]>
Hot cocoa tops red wine and tea in antioxidants; may be healthier choice
Journal of Agricultural and Food Chemistry
There's sweet news about hot cocoa: Researchers at Cornell University have shown that the popular winter beverage contains more antioxidants per cup than a similar serving of red wine or tea and may be a healthier choice.
The study adds to growing evidence of the health benefits of cocoa and points to a tasty alternative in the quest to maintain a diet rich in healthy antioxidants, chemicals that have been shown to fight cancer, heart disease and aging, the researchers say.
Their study, which they say is the most complete comparison to date (2003) of the total antioxidant content of these three popular beverages, appears in the Dec. 3, 2003, issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.
"Although we know that antioxidants are important for good health, nobody knows the exact daily amount required per person," says Chang Yong Lee, Ph.D., head of the study and a professor of food chemistry in Cornell's Department of Food Science and Technology, located in Geneva, N.Y. "Nevertheless, a cup or two of hot cocoa every once in a while can provide a delicious, warm and healthy way to obtain more antioxidants."
Many recent studies have touted the health benefits of red wine and tea, all of which are known to be high in antioxidants. Although researchers have been aware for some time that cocoa is also rich in these compounds, its relative contribution in comparison to other beverages has been unclear, says Lee.
To gain a better understanding of how these beverages compare in terms of antioxidants, the researchers tested them using similar serving sizes and conditions. The beverages tested included a cup of hot water containing two tablespoons of pure cocoa powder, roughly equivalent to the amount of cocoa in a normal-size packet of instant hot chocolate; a cup of water containing a standard size bag of green tea; a cup of black tea; and one glass of red wine (California Merlot).
Using special analytical techniques to evaluate the total antioxidant content in each beverage, the researchers showed that, on a per serving basis, the antioxidant concentration in cocoa was the highest: It was almost 2 times stronger than red wine, 2-3 times stronger than green tea, and 4-5 times stronger than that of black tea.
For those who want the tasty treat but also want to avoid extra sugar and dairy products that are common additives to cocoa, healthier alternatives are possible: Skim or soy milk can substitute for regular milk, while an artificial sweetener can replace the sugar.
Although you can enjoy cocoa either hot or cold, the hot version tends to trigger the release of more antioxidants than its cold counterpart, the researcher says.
Antioxidant-rich cocoa is also found in many different products including desserts, sauces, liqueurs and candy bars, which differ widely in their cocoa content. But when given a choice between getting your antioxidant fix from a cup of cocoa or a candy bar, it is better to go with the drinkable stuff, says Lee. A normal 40-gram bar of chocolate contains about 8 grams of saturated fat, compared to only 0.3 grams in an average cup of hot cocoa, he notes.
Although many other popular beverages, such as coffee and cranberry juice, also contain high levels of antioxidants, these were not evaluated in this particular study, Lee and his associates say.
Perhaps the best way to ensure that you get plenty of antioxidants is to eat a variety of fruits and vegetables, experts say.
Funding for this study was provided in part by the Rural Development Administration, Republic of Korea.
— Mark T. Sampson
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Dark chocolate: A heart-healthy treat
Journal of Agricultural and Food Chemistry
Few holiday celebrations would be complete without chocolate, whether eaten alone or as part of a dessert. Researchers at the University of Scranton in Pennsylvania say the popular treat, especially dark chocolate, may help prevent heart disease. The scientists showed that cocoa powder, at levels equivalent to two dark chocolate bars per day, significantly reduced chemical markers for heart disease in a group of lab animals on a high-fat diet. Their study was published in the September 16, 2006, issue of the ACS Journal of Agricultural and Food Chemistry.
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CONTACT:
Joe Vinson, Ph.D.
Chemist
University of Scranton
Scranton, Penn.
Phone: 570-941-7551
E-mail: [email protected]