Chocolate…..the very word evokes pleasant contemplations of its exquisite taste and velvety texture in your mouth. Its ingestion is so heavenly that “healthy” cannot possibly be associated with it … can it? Unexpectedly it seems that chocolate can bestow significant wholesome benefits. You just need to make some smart choices before you enjoy.
The word “chocolate” originates as far back as 1100 BC with the Aztec word “xocolati,” referring to a bitter drink brewed from cacao beans ground together with pepper and corn. The Latin name for the cacao tree, Theobroma cacao, aptly means “food of the gods.” The ancient Aztecs used cacao for currency and as a medical remedy for illness. Chocolate arrived in Europe much later and it was not until 1839 that the Cadbury company in England created the first actual chocolate bar.
Cacao beans, in the botanical sense, are seeds, a whole plant surrounded by a tough shell and packed with vitamins, minerals and phytochemicals to protect the tiny plant’s DNA from free radicals. This makes it not too surprising that this little brown bean offers health-promoting effects. Indeed, independent research studies over the past couple of decades demonstrate the impressive cardio-protective health benefits of cocoa (1).
A note on the difference between cacao and cocoa: (22,23,24)
Cacao beans have very high antioxidant levels that are retained during the cold-pressing process that removes the natural fat and cacao butter and the subsequent fermentation which preserves and darkens the cacao mash. Cacao powder can be made from the mash.
Cocoa powder comes from cacao beans that have undergone fairly high heat temperatures during processing, however the resulting powder does not have to lose its antioxidant power. Most cocoa does undergo “Dutch processing” wherein it is processed with an alkali to raise the pH, removing some of its natural bitterness but unfortunately destroying as much as 90% of its flavonoids, depending on the chemicals and amount of heat used. Cocoa that has not been “dutched” still retains a large proportion of its original antioxidants.
Dark chocolate is defined as chocolate with no added milk and containing a cocoa content ranging from 30% to 80% by weight.
There are many active substances in cocoa that have the potential to contribute significant health benefits. Some of these are theobromine, magnesium, N-acylethanolamines, polyphenols and flavonoids such as catechin and epicatechin. The most compelling health evidence points to the beneficial effects of flavonoids, especially epicatechin (11,12) Flavanoids are found in many fruits and vegetables including cocoa beans. Flavonoids are antioxidants that help cells in the body to resist inflammation and damage caused by free radicals. Free radicals are harmful molecules resulting both from normal body processes (breathing, inflammation, mental stress, excessive exercise, infection, cancer, ageing) and from environmental contaminants (cigarette smoke, pollution, radiation, medication) (2).
Effects of flavonoids and theobromine:
Continuing research is illustrating the strong association between the consumption of cocoa and its flavonoids with the lowering of cardiovascular risk factors. Benefits include reduced blood pressure, decreased insulin resistance, lower inflammation as well as better blood vessel health and cholesterol levels (15,16,17).
A meta-analysis was published in the Journal of Nutrition in 2011 reviewing controlled trials of 1100 adults who ingested cocoa for four weeks. The results showed significant decreases in systolic blood pressure, both LDL and HDL cholesterol and insulin resistance. Artery health improved, as shown by increased flow-mediated dilation of blood vessels (4).
In addition, other meta-analyses showed improved endothelial and blood vessel function in patients with heart failure who ingested flavanoid-rich chocolate over a four-week period. (5)
Increasing evidence points to beneficial effects of moderate consumption of cocoa and cocoa-containing foods on metabolic syndrome, inflammation and endothelium health with flavanoids playing a major role in these effects (18).
An unexpected benefit of the flavonoids and fiber in cocoa beans comes from the feeding of “good” bacteria in the gut such as Bifidobacterium and lactic acid bacteria who reward us by producing anti-inflammatory factors that decrease inflammation in the body (7).
Cocoa beans naturally contain about 1% theobromine while cocoa powder varies in its theobromine content from 2% to 10%. Theobromine is a mild stimulant that works synergistically with the low amount of caffeine in chocolate to improve alertness and mood. Theobromine also benefits the cardiovascular system by stimulating smooth muscles causing them to dilate and by increasing the level of salt and water that exit the body in the urine. Together these actions ultimately reduce blood pressure (6).
What about chocolate itself?
Numerous studies have looked at the benefits of eating prepared chocolate, especially dark chocolate.
A meta-analysis published in 2012 looked at 42 randomized, controlled trials and found strong beneficial effects of both cocoa flavonoids and chocolate on arterial health as well as improved insulin resistance. (3)
A prospective study investigated the relationship between moderate chocolate consumption and the risk of stroke in men and found a 19% lower risk of stroke in the chocolate eaters (13).
Ingestion of flavonoid-rich dark chocolate (70% cocoa) was found to increase coronary vasodilation (relaxation of the blood vessels that supply the heart with oxygen) and to decrease platelet “stickiness” (lowering the risk of atherosclerosis and stroke) compared to ingestion of cocoa-free chocolate (17).
A 2014 review looked into the associations of dark chocolate with decreased blood pressure and improved cardiovascular disease risk and found that eating dark chocolate can indeed be a pleasurable method of reducing cardiovascular risk (19).
Dark chocolate compared to milk chocolate has even been studied regarding peripheral artery disease. This debilitating condition of atherosclerosis in the arteries feeding the legs leads to impaired blood flow causing cramping pain and greatly limiting ability to walk any distance. Two hours after eating dark chocolate containing 85% cocoa, subjects were able to walk about 12 meters longer than the distance they walked before eating the dark chocolate. After eating milk chocolate they were unable to walk even as far as they could at baseline (14).
Moreover other studies show that eating dark chocolate decreases the total amount of food eaten in a day compared to eating milk chocolate. Dark chocolate promotes satiety, lowering the desire to eat sugary foods. In one study total energy intake was lowered by 17% after consumption of dark chocolate compared with milk chocolate. The reason for this may be that dark chocolate contains over 70% cocoa while milk chocolate contains only 30%. The resulting more intense flavour of the dark chocolate may lead to a stronger feeling of eating satisfaction (8). The issue with milk chocolate is its milk ingredient which can block the absorption of flavonoids.
Is chocolate associated with weight gain? This question has been contested in the last few years with some investigations claiming that eating chocolate leads to lower weight. For instance, a study published in 2012 followed 1000 men and women, concluding that those who consumed chocolate more frequently had a lower body mass index and weighed less than those indulging in less chocolate. The researchers adjusted for diet quality and physical activity (25). However this and other similar studies were observational, looking at a population at one point in time only, and cannot prove cause and effect. Recently, two more robust studies, a prospective study and an interventional trial, have added clarity and substance to the answer to this question. In 2013 the results of a prospective study, following more than 10,000 people for six years, illustrated that the greatest weight gain occurred in the subjects eating the most chocolate (26). The year 2014 brought an interventional trial where people were split up into two groups, one group adding four squares of chocolate to their daily diet and the other group making no changes. The chocolate-eating group gained 2 to 4 pounds of weight over three months (27). It appears that eating moderate amounts of chocolate does cause long term weight gain.
What about caffeine?
Chocolate contains some caffeine and, as the cocoa content increases, so does the caffeine. Each ounce of dark chocolate contains between 5 and 10 mg of caffeine. To put this into perspective, coffee contains from 47 mg caffeine in a one ounce espresso to 165 mg of caffeine in a regular brewed coffee. Tea ranges from 25 mg in green tea to 48 mg in black tea (28).
What is the final conclusion about chocolate?
Science has shown us that eating the cacao bean in its many different forms can;
Increase the health and function of the endothelium within our blood vessels
Reduce blood pressure
Reduce risk of stroke
Decrease insulin resistance
Reduce cholesterol levels
Decrease metabolic syndrome
Reduce symptoms of peripheral artery disease
Improve alertness and mood
Reduce total energy intake
Cause weight gain over time
Remember the mention above of smart choices regarding chocolate? Here’s where they come into play. Cacao, cocoa and dark chocolate can be healthy; ingredients such as sugar, fat and milk added during their processing are not. Dark chocolate contains triple the antioxidants of milk chocolate. In addition milk actively inhibits the absorption of antioxidants into the bloodstream (20). Sugar itself can cripple artery function (21). The high fat in chocolate comes from added cocoa butter (the cream-colored fat extracted from cacao beans) which consists of equal amounts of oleic, stearic and palmitic acids. Stearic and palmitic acids are forms of saturated fat while oleic acid is a monounsaturated fat. Saturated fats are linked to increases in LDL cholesterol and the risk of heart disease although stearic acid appears to have a neutral effect on cholesterol (29).
The best way to achieve the beneficial effects of cocoa is through eating cocoa powder (9,10). Cocoa powder contains a high concentration of antioxidants and no sugar or fat. In fact, natural cocoa powder that has not been put through a “dutching” process can be considered a health food and there is no need to limit the amount you eat. Scientists studying the benefits of cocoa sometimes use isolated and purified compounds extracted from cocoa while others simply use pure cocoa powders. Investigations into the flavonoid source used in different studies have concluded that, as long as the cocoa source has not undergone “dutching”, differences resulting from various cocoa blends and processing methods are minor factors in determining the antioxidant levels in the resulting cocoa powder.
Be sure to read labels. If you are looking to reap the benefits of cocoa, buy only pure “undutched” cocoa or cacao powder with no added sugar or other ingredients. There are many recipes that can be made using cocoa powder which offer the alluring flavour of chocolate without its less healthy sugar and fat companions. In Monday’s blog post I’ll share one of our favourites.
If you feel you need some actual chocolate, choose dark chocolate with a high concentration of cacoa and little added sugar or fat and try to keep your portions to a moderate level. Nowadays many manufacturers of chocolate, knowing the importance of the health benefits of the flavonoids in chocolate, are striving to retain flavonoid action in their chocolates. But be forewarned! The highly processed and sugar laden chocolate candy most commonly available for purchase is a completely different kettle of fish. It does not offer any of the benefits that we have been talking about and, in fact, can cause negative health effects.
Above all, know that you can enjoy chocolate, that tantalizing assault to the senses, without guilt and with the knowledge that it might be doing your body good.
1 Kaynak, H.E., Taegtmeyer, H. Is bitter better? The benefits of chocolate for the cardiovascular system. Curr Hypertens Rep. 2011 Dec; 13(6):401-3.
2 Lien, A.P., Hua, H., Chuong, P. Free Radicals, Antioxidants in Disease and Health. Int J Biomed Sci. 2008 Jun; 4(2): 89–96.
3 Hooper, L., Kay, C., Abdelhamid, A. et al. Effects of chocolate, cocoa, and flavan-3-ols on cardiovascular health: a systematic review and meta-analysis of randomized trials. Am J Clin Nutr. 2012 Mar; 95(3):740-51.
4 Shrime, M.G., Bauer, S.R., McDonald, A.C., Chowdhury,N.H. et al. Flavonoid-rich cocoa consumption affects multiple cardiovascular risk factors in a meta-analysis of short-term studies. J Nutr. 2011 Nov; 141(11):1982-1988.
5 Flammer, A.J., Sudano, I., Wolfrum, M., Thomas, R., et al. Cardiovascular effects of flavanol-rich chocolate in patients with heart failure. Eur Heart J. 2012 Sep; 33(17):2172-2180.
6 Berends, L.M., van der Velpen, V., Cassidy, A. Flavan-3-ols, theobromine, and the effects of cocoa and chocolate on cardiometabolic risk factors. Curr Opin Lipidol. 2015 Feb; 26(1):10-19.
7 Finley, John. The precise reason for the health benefits of dark chocolate: mystery solved. American Chemical Society News News Releases March 18, 2014
8 Sørensen, L.B., Astrup, A. Eating dark and milk chocolate: a randomized crossover study of effects on appetite and energy intake. Nutrition and Diabetes (2011) 1, e21
9 Taubert, D., Roesen, R., Lehmann, C., Jung, N., Schömig, E. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA. 2007 Jul 4; 298(1):49-60.
10 Ferri, C., Grassi, D., Grassi, G. Cocoa beans, endothelial function and aging: An unexpected friendship? J. Hypertens. 2006; 24 (8):1471-1474.
11 Kerimi, A., Williamson, G. The cardiovascular benefits of dark chocolate. Vascul Pharmacol. 2015 Aug; 71:11-15.
12 Higginbotham, E., Taub, P.R. Cardiovascular Benefits of Dark Chocolate? Curr Treat Options Cardiovasc Med. 2015 Dec; 17(12):54.
13 Larsson, S.C., Virtamo, J., Wolk, A. Chocolate consumption and risk of stroke: a prospective cohort of men and meta-analysis. Neurology. 2012 Sep 18; 79(12):1223-1229.
14 Loffredo, L., Perri, L., Catasca, E., Pignatelli, P. et al. Dark chocolate acutely improves walking autonomy in patients with peripheral artery disease. J Am Heart Assoc. 2014 Jul 2; 3(4).
15 Kwok, C.S., Boekholdt, S.M., Lentjes, M.A., Loke, Y.K. et al. Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women. Heart. 2015 Aug; 101(16):1279-87.
16 Hollenberg, N.K., Fisher, N.D. Is it the dark in dark chocolate? Circulation. 2007 Nov 20; 116(21):2360-2.
17 Flammer, A.J., Hermann, F., Sudano, I., Spieker, L. et al. Dark chocolate improves coronary vasomotion and reduces platelet reactivity. Circulation. 2007 Nov 20; 116(21):2376-82.
18 Gu, Y., Lambert, J.D. Modulation of metabolic syndrome-related inflammation by cocoa. Mol Nutr Food Res. 2013 Jun; 57(6):948-961.
19 Latham, L.S., Hensen, Z.K., Minor, D.S. Chocolate–guilty pleasure or healthy supplement? J Clin Hypertens (Greenwich). 2014 Feb; 16(2):101-106.
20 Serafini, M., Bugianesi, R., Maiani, G., Valtuena, S., De Santis, S., Crozier, A. Plasma antioxidants from chocolate. Nature 2003 424(6952):1013 – 1013.
21 Njike, V.Y. Faridi, Z., Shuval, K., Dutta, S., Kay, C.D. et al. Effects of sugar-sweetened and sugar-free cocoa on endothelial function in overweight adults. Int. J. Cardiol. 2011 149(1):83 – 88.
22 Andres-Lacueva, C., Monagas, M., Khan, N., Izquierdo-Pulido, M et al. Flavanol and flavonol contents of cocoa powder products: influence of the manufacturing process. J Agric Food Chem. 2008 May 14; 56(9):3111-3117.
23 Miller, K.B., Stuart, D.A., Smith, N.L., Lee, C.Y. et al. Antioxidant activity and polyphenol and procyanidin contents of selected commercially available cocoa-containing and chocolate products in the United States. J Agric Food Chem. 2006 May 31; 54(11):4062-4068.
24 Miller, K.B. et al. Impact of alkalization on the antioxidant and flavanol content of commercial cocoa powders . Journal of Agricultural and Food Chemistry, 2008; 56 (18):8527-33.
25 Golomb, A.B., Koperski, S., White, H.L. Association Between More Frequent Chocolate Consumption and Lower Body Mass Index . Arch Intern Med. 2012; (6):519-521.
26 Greenberg, J.A., Buijsse,B. Habitual chocolate consumption may increase body weight in a dose-response manner. PLoS One. 2013 Aug 7; 8(8):e70271.
27 Desch, S., Kobler, D., Schmidt, J. et al. Low vs. Higher-Dose Dark Chocolate and Blood Pressure in Cardiovascular High-Risk Patients American Journal of Hypertension June 2010; 23 (6): 694–700.
29 Mensink, R.P. Effects of stearic acid on plasma lipid and lipoproteins in humans. Lipids 2005; 40: 1201-1205,