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October 23, 2008
Chocolate, the epitome of sweet satisfaction and the treat that most taste buds desire. The delectable indulgence, once thought of as “food for the gods,” has now grown into a multi-billion dollar industry worldwide. With more than two billion pounds being produced annually in America, chocolate has become one of the most craved desserts. The treat is also a sweet taboo, with the growing rate of obesity in America, chocolate has been stigmatized as more harmful than helpful. Women often think twice about reaching for that chocolate bar when trying to lose weight, and teenagers avoid chocolate at all costs in fears that it will trigger acne. However, recent studies have shown that consumption of dark chocolate may have health benefits. The improvement of cardiovascular health has been the main emphasis of the studies done on dark chocolate.
But, could this possibly be a license to binge? Too much of a good thing in any case is bad; however, dark chocolate in moderation may turn out to be just what the doctor ordered!
Chocolate comes from cocoa beans, which are the seeds of the fruit that grow on the cacao tree named Theobroma cacao. However, there is a definite distinction between regular chocolate and dark chocolate. Dark chocolate contains several ingredients that together have been proven to help promote cardiovascular health such as, better blood flow, and lower blood pressure. Dark chocolate is more concentrated in cocoa content, which contains flavanol antioxidants. More than 10% of the weight of the raw cacoa beans consists of polyphenols (the antioxidants found in chocolate) alone. Flavanols belong to a group of chemicals called phytochemicals, which are found in most fruits and vegetables. These fighter chemicals defuse unstable and extremely reactive molecules, called free radicals. http://www.rice.edu/~jenky/sports/antiox.html
A free radical is an atom or groups of atoms with an odd number of electrons. The radicals form when oxygen interacts with certain molecules within the body. The radicals can cause changes in the structure of normal cells, and can have catastrophic effects when interacting with DNA or the cellular membrane. The interaction could result in cell death, dysfunction, or damage. Free radical damage is believed to contribute to a variety of health problems, including cancer, heart disease and aging. http://www.tonytantillo.com/reference/phyto.html
Millions of websites claim chocolate has a plethora of health benefits, but is it all true? One website suggests chocolate will give you an overall healthier heart. The website seems legit; its focus is on improving the immune system. However, smack dab in the middle of the page stands a link that you can click on to purchase all the chocolate you want. http://www.immunesupport.com/library/showarticle.cfm/ID/3464/
This is a good way to communicate the health benefits and persuade a purchase. But, all these websites advocate simply purchase behavior. Websites without a scientific basis or connected to some sort of academic or research institution had several links that would take you straight to a place that would allow you to purchase chocolate, not dark chocolate, but several types. In theory, this is easy access to a market for a consumer, but these websites used skewed non-evidence based facts to persuade a customer.
With the growing frenzy of chocolate’s possible benefits it is so easy to get swept up in all the circulating information. So, with the help of scientific research, chocolate’s actual benefits can be assessed. Several scientific based studies have been done to acquire the actual quantitative evidence that chocolate actually improves one’s health. A study published in the American Journal of Clinical Nutrition examined the benefits of dark chocolate 29 day period.
The Objective: The objective of the study was to test the effects of dark chocolate and white chocolate on blood pressure and glucose levels.
The Set-Up: 15 healthy participants first went on a 7- day chocolate free run. After the 7 days they were randomly assigned to receive for 15 days either 100 grams of dark chocolate bars (which contained 500 mg of polyphenols) or 90 grams of white chocolate bars (which contained no polyphenols). Subjects then went through a 7 day “washout phase” and were then crossed back over to the other condition.
The Data: Oral-glucose-tolerance tests were performed at the end of each period to calculate the homeostasis model assessment of insulin resistance and the quantitative insulin sensitivity check index; blood pressure was measured daily.
The Results: Insulin resistance was significantly lower after white chocolate ingestion and although within normal values, systolic blood pressure was lower after dark than after white chocolate ingestion. Thus, Dark, but not white, chocolate decreases blood pressure and improve insulin sensitivity in healthy persons.
In a similar study done by the Defeat Diabetes Foundation, Jeffrey B. Blumberg, a professor of nutrition at Tufts University put together a group of 10 men and 10 women eat 3.5 ounces of dark chocolate every day for 15 days. The difference in this study is that all of these subjects originally had high blood pressure and were not on any types of medication. First, the researchers had five of the men and five of the women eat dark chocolate while the others ate white chocolate, which contains no flavonoids. Then after another week of no chocolate, the groups switched and ate the other chocolate. In the 15 days they were eating dark chocolate, individuals displayed an average 11.9 mm Hg drop in their systolic blood pressure and a 8.5 mm Hg drop in diastolic blood pressure (the lower number). However, there was no drop in blood pressure when they ate flavonoid-free white chocolate, the researchers found. Thus, dark chocolate has a positive effect on blood pressure.
There seems to be some positive correlation between an improved blood pressure insulin levels and dark chocolate. Several studies have shown that the flavanols and antioxidants in dark chocolate do help improve these two aspects of the cardiovascular system. However, all the scientific research done did not supply us with an exact amount of dark chocolate that would significantly improve the cardiovascular system of individuals after consumption. A diet consisting heavily of dark chocolate would do more harm than good, so it is recommended to moderate the intake of dark chocolate and accompany it with a balanced diet and exercise. Although there are positive effects of dark chocolate do not expect to go to the doctor and hear him say “Eat a dark chocolate candy bar, and call me in the morning!”
Cooper KA, Donovan JL, Waterhouse AL, Williamson G. (2008) Cocoa and Health: a decade of research. Epub 2007 Aug 1.
Grassi, D., Necozione, S., Lippi, C., Croce, G., Valeri, L., Pasqualetti, P., Desideri, G., Blumberg, J.B., Ferri, C. Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives. American Journal of Clinical Nutrition Vol. 81, No. 3, 611-614, March 2005.
Reinberg, Steven (2005, July 28). Dark Chocolate May Sweeten the Way to Health. Health Day Reporter.
About.com (2008) Health Benefits of Chocolate. Retrieved from September 28, 2008, from http://longevity.about.com/od/lifelongnutrition/p/chocolate.html.
Taubert, D., Roesen, R., Lehmann, C., Jung, N., Schomig, E. Effects of Low Habitual Intake on Blood Pressure and Bioactive Nitric Oxide. JAMA. 298:49-60. 2007.
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