Nutrition 302 Claims Evaluation
February 23, 2010
Chocolate is an indulgence that seems to have the power to fix a terrible day, ease the
misery of P.M.S., and cure all types of boredom. But, some medical professionals say that it has
another power to lower blood pressure. This power is reported as only belonging to one type of
chocolate: dark chocolate. While most people eagerly latch onto this claim in an attempt to enjoy
dark chocolate guilt-free, few of these people are actually informed of the validity, or lack
thereof, in this claim. Exploration of the scientific support of this claim is vital to an accurate
portrayal of the facts versus the fiction.
The source of dark chocolate’s power to lower blood pressure was found, in a 1996 study
under Andrew Waterhouse, to be a result of the presence of cocoa phenols. Cocoa phenols are a
type of antioxidant that lowers blood pressure by controlling the buildup of arterial plaque.
Instead of allowing low-density lipoprotein (L.D.L.) cholesterol to build up inside arterial walls,
cocoa phenols were actually found to prevent this from occurring. Other studies have confirmed
these findings. (Yale-New Haven 1)
Dirk Taubert, a researcher at the University of Cologne, Germany, facilitated a study that
was designed to exclusively explore the relationship between blood pressure and cocoa phenols
found in dark chocolate. In his study, thirteen middle-aged men and women were each given one
100-gram chocolate bar every day for fourteen days. Participants were either given a dark
chocolate bar that contained cocoa phenols, or they were given a white chocolate bar. The white
chocolate bar served as a control because it did not contain cocoa phenols. All of the participants
had documented blood pressure levels above the normal range at the beginning of the study.
When the fourteen days were over, the participant’s blood pressure levels were measured. The
results of the study showed that cocoa phenols do have a lowering effect on blood pressure
because those who received the dark chocolate bar had an average drop of 5 points of systolic
blood pressure and 2 points of diastolic blood pressure. However, the participants who were
given white chocolate bars did not display any documentable blood pressure changes. (Denoon
In 2007, Dr. Taubert conducted a follow-up to his original study. This follow-up study
was designed to account for the unrealistic variables present in the first study. For example, the
first study was done over a very short period of time, only two weeks. In addition, the daily
chocolate dose of 100 grams was unrealistically high. In order to address these issues, Dr.
Taubert redesigned the follow-up study so that blood pressure measurements were taken
periodically for eighteen weeks. Also, the daily dose of chocolate (whether white or dark
chocolate) was reduced from 100 grams to about 6 grams per day. Having addressed the
variables of duration and dose, Dr. Taubert and his colleagues were able to apply the results of
this second study much more pointedly. (Nordmoe 2)
The results of the second study did not disappoint the public. Using various t-tests and
linear correlation and regression analysis, Dr. Taubert found statistically significant decreases in
blood pressure in the group of participants who were given the small dose of dark chocolate as
opposed to the small dose of white chocolate (Nordmoe 2). From this study, considered by many
to be the pivotal study on health benefits of dark chocolate, the health claim that dark chocolate’s
cocoa phenols lower blood pressure finds its validity and scientific support. Due to the well-
researched and thoroughly-documented nature of this health claim, I personally recommend
consuming a moderate amount of dark chocolate at least three to four times per week.
Moderation is the key, however, and if consumers do not closely monitor their consumption of
dark chocolate, caloric content could easily climb too high. As long as consumers are careful to
incorporate dark chocolate into a healthy and well-balanced diet, the benefits of dark chocolate
are worth the extra calories.
"Chocolate: Food of the gods." Yale-New Haven Nutrition Advisor 10 Mar 2005: n. pag. Web. 22
Feb 2010. <http://www.ynhh.org/online/nutrition/advisor/chocolate.html>.
Denoon, Daniel. "Dark Chocolate Is Healthy Chocolate." WebMD News 27 Aug 2003: 1-2. Web.
22 Feb 2010. < http://www.webmd.com/diet/news/20030827/dark-chocolate-is-healthy-
Nordmoe, Eric. "Kiss High Blood Pressure Goodbye: The Relationship between Dark Chocolate
and Hypertension." Teaching Statistics Trust 2008: 1-5. Web. 22 Feb 2010.