Made from the beans of the cocoa tree, chocolate was first developed as a food in South America, where it was primarily consumed as a bitter beverage. Cocoa was not combined with sugar until the Spaniards brought chocolate back to Europe. The Latin name of the plant is Theobroma cocoa. "Theobroma" means food of the gods. Because of this, one of the stimulant substances in chocolate is named theobromine; this caffeine-related substance does not contain the element bromine.
Chocolate is rich in antioxidants in the flavonol family, substances similar to those found in green tea, red wine, grapes, soy and other potentially healthful foods. However, this alone is not enough to prove that chocolate provides any health benefits. In gigantic studies of other strong antioxidants, such as vitamin E, none of the hoped-for benefits materialized. Only double-blind, placebo-controlled studies can prove a treatment effective, and for chocolate few have been performed. (For information on why such studies are essential, see Why Does This Database Rely on Double-Blind Studies?)
Nonetheless, some potential benefits have been seen in preliminary trials. A controlled study of 20 males with mild hypertension compared the effects of 100 g daily of a flavonol-rich dark chocolate as compared to a flavonol-free white chocolate.1 Results appeared to indicate that the dark chocolate produced improvements in blood pressure. A subsequent study of similar design, this one enrolling 44 people with mild hypertension, found that a much lower dose of dark chocolate (6.3 g daily), also significantly reduced blood pressure levels.11 A review including several additional studies drew the same conclusion regarding chocolate’s modest yet favorable effect on blood pressure.12 A larger analysis of 20 trials studied 856 patients with and without hypertension. The trials compared flavonol-rich cocoa products to low or non-flavonol foods for an average of 4 weeks. Cocoa was found to significantly decrease systolic blood pressure in 20 trials and diastolic blood pressure in 19 trials.13
Chocolate has also shown some promise for improving cholesterol profile. In one study, 57 people with high cholesterol were given either a standard snack bar or a snack bar enriched with cocoa flavanols.7 Over 6 weeks, the results appeared to indicate that cocoa improved cholesterol levels to a greater extent than placebo. Two other preliminary studies found evidence that consumption of chocolate can improve levels of HDL (“good”) cholesterol.9,10
A review of several observational studies of 20,951 healthy adults found those with a habitual, high intake of chocolate (16-99 g daily) had a reduced risk of cardiovascular disease when compared to those who did not eat chocolate. Cardiovascular disease was defined as a fatal or non-fatal cardiovascular event, stroke, or coronary artery disease.14 Similar results were found in multiple reviews that included 144,823 adults. Consumption of 3-4 servings a weeks of chocolate was associated with a lower risk of heart attack, stroke, and coronary artery disease. The type of chocolate and the amount consumed per week were not identified.15
One double-blind study failed to find that flavanol-rich cocoa improved blood vessel health in people with established cardiovascular disease.3
Besides flavonols, chocolate contains a fat called stearic acid. Although it is a saturated fat, stearic acid is hypothesized to have cardiovascular-preventive benefits. However, this is not yet proven.2
Like other antioxidants, consumption of high flavonol cocoa might also offer some protection to the skin from UV damage.4 This could, in theory, help prevent sunburn, reduce symptoms of photosensitivity, and help prevent age-related skin changes. However, the benefits would be small compared to standard sunblock.
An unpublished double-blind study (available only in the form of a press release) reportedly found that dark chocolate is helpful for chronic fatigue syndrome.8
In studies, the typical daily dose of flavanols from chocolate thought to offer a beneficial effect range widely from 30 to 500 mg per day.
The flavanol content of chocolate itself also varies widely. White chocolate contains little to no flavanols, commercial dark chocolate can contain as much as 500-2,000 mg of flavonols per 100 grams of chocolate. Special flavonol-enriched forms of chocolate are also available.
As a widely consumed food, chocolate is assumed to have a high safety factor. However, because of its caffeine and theobromine content, it would be expected to have potential side effects similar to those of coffee and black tea, namely: heartburn, gastritis, insomnia, anxiety, and heart arrhythmias (benign palpitations or more serious disturbances of heart rhythm.)6 All drug interactions that can occur with caffeine would be expected to occur with chocolate as well.
Most chocolate products are high in calories, and therefore could lead to weight gain.
If you are taking:
Grassi D, Necozione S, Lippi C et al. Cocoa Reduces Blood Pressure and Insulin Resistance and Improves Endothelium-Dependent Vasodilation in Hypertensives. Hypertension. 2005 Jul 18. [Epub ahead of print]
Ding EL, Hutfless SM, Ding X et al. Chocolate and Prevention of Cardiovascular Disease: A Systematic Review. Nutr Metab (Lond). 2006 Jan 3. [Epub ahead of print]
Farouque HM, Leung M, Hope SA et al. Acute and chronic effects of flavanol-rich cocoa on vascular function in subjects with coronary artery disease: a randomized, double-blind, placebo-controlled study. Clin Sci (Lond). 2006 Mar 22. [Epub ahead of print]
Heinrich U, Neukam K, Tronnier H et al. Long-term ingestion of high flavanol cocoa provides photoprotection against UV-induced erythema and improves skin condition in women. J Nutr. 2006;136:1565-1569.
Usmani OS, Belvisi MG, Patel HJ et al. Theobromine inhibits sensory nerve activation and cough. FASEB J. 2005;19:231-233.
Cannon ME, Cooke CT, McCarthy JS. Caffeine-induced cardiac arrhythmia: an unrecognised danger of healthfood products. Med J Aust. 2001;174:520-521.
Polagruto JA, Wang-Polagruto JF, Braun MM, et al. Cocoa Flavanol-Enriched Snack Bars Containing Phytosterols Effectively Lower Total and Low-Density Lipoprotein Cholesterol Levels. J Am Diet Assoc. 2006;106:1804-1813.
Health Benefits of Chocolate Revealed. Hull and East Yorkshire Hospitals NHS Trust website. Available at: http://www.hey.nhs.uk/pdf/media/chocolate.pdf. Accessed December 21, 2006.
Baba S, Osakabe N, KatoY, et al. Continuous intake of polyphenolic compounds containing cocoa powder reduces LDL oxidative susceptibility and has beneficial effects on plasma HDL-cholesterol concentrations in humans. Am J Clin Nutr. 2007;85:709-717.
Baba S, Natsume M, Yasuda A, et al. Plasma LDL and HDL cholesterol and oxidized LDL concentrations are altered in normo- and hypercholesterolemic humans after intake of different levels of cocoa powder. J Nutr. 2007;137:1436-1441.
Taubert D, MD, Roesen R, Lehmann C, et al. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide. JAMA. 2007;298:49-60.
Hooper L, Kroon PA, Rimm EB, et al. Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2008;88:38-50.
Ried K, Sullivan TR, Fakler P, et al. Effect of cocoa on blood pressure. Cochrane Database Syst Rev. 2012;8:CD008893.
Kwok CS, Boekholdt SM, Lentjes MA, et al. Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women. Heart. 2015;101(16):1279-1287.
Larsson SC, Åkesson A, Gigante B, Wolk A. Chocolate consumption and risk of myocardial infarction: a prospective study and meta-analysis. Heart. 2016 ;102(13):1017-1722.
Last reviewed December 2015 by EBSCO CAM Review Board
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