Chocolate is derived from Theobroma cacao seeds (Theobroma means “food for the deities”) that are roasted, ground, fermented and then flavored.
Christopher Columbus and his son Ferdinand encountered cocoa beans in 1502 during a trip to the Americas and carried beans back to Spain. After the Spanish conquest of the Aztec Empire in 1521, chocolate was imported to Europe, and it soon became a fashionable drink of the nobility.
In 1893, Milton Hershey revolutionized the process of making milk chocolate, introduced mass production techniques and transformed chocolate into a sweet taste for everyone.
As Valentine’s Day approaches, test your knowledge of chocolate. Which of the following statements are true?
a.) Chocolate with a high cocoa concentration is the healthiest but also the most bitter.
b.) Consumption of two chocolate bars a day for four weeks is likely to result in a reduction in serum low-density lipoprotein levels.
c.) Chocolate enhances cognitive function, and a direct correlation exists between a country's annual per capita chocolate consumption and the number of Nobel laureates.
d.) Regular consumption of flavanol-rich chocolate has been shown to lower blood pressure by a statistically significant amount.
e.) Consumption of dark chocolate is helpful for people with iron deficiency anemia.
Answer: All statements are true. Dark chocolate is a rich source of iron.
Chocolate is one of the most popular food types in the world. Although cocoa originated in the Americas, West Africa now produces two-thirds of the world's cocoa with about 45% coming from the Ivory Coast. Estimates suggest that 50 million people around the world rely on cocoa as a source of livelihood.
Dietary flavonoids have been shown to improve cognition and reduce the risk of dementia. A subclass of flavonoids called flavanols are present in cocoa, green tea and red wine. One study demonstrated a surprisingly strong correlation (correlation coefficient 0.862) between chocolate consumption per capita and the number of Nobel laureates per 10 million people in 23 countries (Messerli FH. New Engl J Med. 2012;367:1562-1564). The author estimated ingestion of 400 grams of chocolate per capita per year would increase the number of Nobel laureates by one.
Because chocolate often is consumed as a sweet, the effect of additional calories on body mass index has been studied. The authors of one study questioned whether the benefit of modest chocolate intake might reduce fat deposition and offset the added calories (Golomb BA, et al. Arch Intern Med. 2012;172:519-521). Results demonstrated that adults who consumed chocolate more frequently had a lower body mass index than those who consumed less chocolate, even though frequent chocolate intake resulted in an increased caloric intake. This result suggests that diet composition as well as number of calories influence body mass index.
The beneficial effect of cocoa on blood pressure has been demonstrated in several studies. Results from one prospective study demonstrated that cocoa intake is inversely associated not only with lower blood pressure but also all-cause and cardiovascular mortality. The association between cocoa intake and cardiovascular mortality did not differ among individuals with high or low physical activity. Consumption of flavanol-rich chocolate has been shown to increase arterial and peripheral vasodilatation in contrast to consumption of a low flavanol chocolate diet.
A Cochrane meta-analysis of 20 trials (Ried K, et al. Cochrane Database Syst Rev. Aug. 15, 2012) concluded there is “a statistically significant blood pressure reducing effect of flavanol rich cocoa products compared with control in short term trials of 2-18 weeks duration.”
Results from a randomized study using a cross-over design indicated that regular consumption of cocoa flavanol-containing chocolate bars significantly lowered serum total and low-density lipid cholesterol levels over a four week trial (Allen RR, et al. J Nutr. 2008;138:725-731).
What is the conclusion?
While most of the studies discussed here pertain to adults, the results indicate that regular consumption of flavanol-containing chocolate as part of a reasonable diet can have a favorable effect on cognition, blood pressure, body mass index, cardiovascular disease and perhaps even on the number of future Nobel laureates. The side effects of chocolate ingestion are seldom a problem.
Dr. Meissner is professor of pediatrics at Floating Hospital for Children, Tufts Medical Center. He also is an ex officio member of the AAP Committee on Infectious Diseases and associate editor of the AAP Visual Red Book.