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Is chocolate good for you?

Norzeihan Jan Bappu and Alan Bagnall have some good news

The earliest texts suggest that cocoa merely helped make less palatable medicines go down.¹ Soon, however, cocoa was regarded as an active ingredient in cures for many illnesses. Diluted into a drink, cocoa was given to people with fevers, liver disease, and kidney disorders. Doctors prescribed ground beans mixed with resin to cure dysentery. A cocoa drink was reputed to foster needed weight gain--especially if bulked out with ground maize. Hot chocolate was even prescribed as a laxative and aid to digestion. By the early 1600s, European researchers were reporting indications that chocolate may affect moods. Grivetti found a 1631 treatise by the Spanish doctor Antoino Comenero de Ledesma, for instance, that said chocolate makes people amiable and "incited consumers to... lovemaking."

It was reported that, as a love potion, drinking chocolate helped women conceive. If hot cocoa was drunk during pregnancy it helped smooth labour and delivery. Three decades later, Henry Stubb published a monograph that claimed a drink made by mixing chocolate and vanilla would strengthen the brain and womb. Mixed with Jamaican pepper, chocolate was supposed to stimulate menstrual flow. Combined with resin, it was reputed to boost production of breast milk. The oils from cocoa beans were even applied to help heal a nursing mother's cracked nipples. Few conditions are not improved by chocolate, according to the texts that Grivetti's team of scholars uncovered and translated. The botanical product was used to treat tuberculosis, toothaches, and ulcers. It was alleged to cure itches, repel tumours, and foster sleep.

By the 1680s, reports emerged that chocolate could restore energy after a day of hard labour, alleviate lung inflammation, or strengthen the heart. By the 1800s, cocoa was being mixed with ground amber dust to relieve hangovers. Combined with other ingredients, it became the basis of treatments for syphilis, haemorrhoids, and intestinal parasites.

Cardiovascular health

Chocoholics who have given up their favourite food thinking it is bad for their health can take heart--some chocolate may actually be good for them. Or at least for their cardiovascular system.²

Chocolate and cocoa are high in flavonoids--compounds found in plants that promote healthy cellular tissue throughout the body--which may act as antioxidants in humans. Antioxidants are believed to help the body cells resist damage by free radicals (formed by numerous processes including the body's cells using oxygen for energy). Flavonoids also positively affect mechanisms involved in maintenance of the cardiovascular system, such as inhibition of platelet aggregation, endothelial function, and eicosanoid balance. Consumption of chocolate in the form of cocoa beverage modifies platelet function in human³:

• Platelet activation, as measured by platelet activation marker expression in response to weak agonists in vitro, was lower after cocoa consumption
• Platelet microparticle formation was reduced after cocoa consumption
• Consumption of cocoa caused an aspirin-like effect on platelet function, as measured in terms of platelet related primary homeostasis.

Chocolate, especially dark chocolate and cocoa, contains a high amount of procyanidins, which help relax the wall of the aorta. This relaxation is controlled by the production of nitric oxide. Research indicates that compounds in chocolate increase nitric oxide concentrations. By activating the nitric oxide synthesis, platelet aggregation (which is the initial step of atherosclerosis) is less likely to happen.

Modulation of eicosanoid synthesis may help to maintain cardiovascular health by reducing blood vessel vulnerability and platelet clumping.³⁴

Obesity

Chocolate is rich in saturated fatty acids, cholesterol, and sugar, and, therefore, when consumed regularly in excessive quantities, may increase the risk of developing non-insulin dependent diabetes mellitus. Limited epidemiological evidence implicates a direct association between chocolate consumption and obesity, however. Chocolate is not an important contributor to the fat or sugar content of the adult diet.⁵ Paradoxically, despite having the highest global per capita chocolate consumption (9.9 kg a year), Switzerland has one of the lowest incidences of obesity and coronary heart disease in western Europe whereas the United States consumes only 4.6 kg/year and has the highest mean body mass index in the Western world.

Mood and anxiety

Chocolate contains about 400 different compounds that can affect mood and anxiety. These molecules selectively cause the release of chemicals, such as serotonin, endorphins, and phenylethylamine. Chocolate is often said to be the most commonly craved food in the world.¹⁴

Several bioactive compounds in chocolate can theoretically contribute to feelings of wellbeing. These include the stimulants theobromine and caffeine; tyramine and phenyletylamine, which are similar to amphetamine; and anamdamide, which mimics a cannabinoid. All these compounds are present in trace amounts in chocolate and are found in many other foods.⁶

Researchers have found that cocoa filled capsules, which contain the same compounds as chocolate, did not satisfy cravings the way chocolate did. This confirms another theory which suggests that the pleasant sensory experience of eating chocolate is necessary to satisfy the desire. Sensory properties associated with chocolate include smooth melt in your mouth textures and the sweet taste commonly found in chocolate of all types.

Only 15% of men crave chocolate; as many as 40% of women do, and 75% of these claim that absolutely nothing other than chocolate can satisfy their appetite. Chocolate cravings may be influenced by a deficiency in magnesium, which is prominent during premenstrual stress.⁷

Cellular systems

Cocoa polyphenols increase cellular antioxidant enzyme activity or antioxidant defence. Also, polyphenolic compounds of dark chocolate may prevent endothelial cell mediated LDL lipid peroxidation and thereby inhibit expression of the haemoxygenase gene. This could be important, since haemoxygenase has been linked with the transformation of monocytes to resident macrophages. Some of these effects may be relevant in preventing endothelial dysfunction and atherosclerosis development.⁷⁸

Not all chocolates are created equal.

Nutritional values are changed by additional ingredients. Chocolate with the highest proportion of cocoa solid has the most nutritional benefit. Next time you have a chocolate craving, do not feel guilty--you are doing yourself a favour.

Norzeihan Jan Bappu fourth year medical student, University of Edinburgh
Email: s0093524@sms.ed.ac.uk

Alan Bagnall specialist registrar in cardiology, New Royal Infirmary of Edinburgh



studentBMJ 2004;12:309-348 SeptemberISSN 0966-6494

1. Binder DK. The medical history of chocolate. [Historical Article. Journal Article] Pharos of Alpha Omega Alpha Honor Medical Society. 64(2):22-6, 2001 Spring.
2. Steinberg FM. Bearden MM. Keen CL. Cocoa and chocolate flavonoids: implications for cardiovascular health. Journal of the American Dietetic Association. 103(2):215-23, 2003 Feb.
3. Kris-Etherton PM. Keen CL. Evidence that the antioxidant flavonoids in tea and cocoa are beneficial for cardiovascular health. Current Opinion in Lipidology. 13(1):41-9, 2002 Feb.
4. Wan Y. Vinson JA. Etherton TD. Proch J. Lazarus SA. Kris-Etherton PM. Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentrations in humans. American Journal of Clinical Nutrition. 74(5):596-602, 2001 Nov
5. Tholstrup T et al. Fat high in stearic acid favourably affects blood lipids and factor VII coagulant activity in comparison with fats high in palmitic acid or high in myristic and lauric acids. American Journal of Clinical Nutrition 1994; 59:371-377
6. Baron AM. Donnerstein RL. Samson RA. Baron JA. Padnick JN. Goldberg SJ. Hemodynamic and electrophysiologic effects of acute chocolate ingestion in young adults. American Journal of Cardiology. 84(3):370-3, A10, 1999 Aug 1.
7. Chou TM. Benowitz NL. Caffeine and coffee: effects on health and cardiovascular disease. Comparative Biochemistry & Physiology. Part C Pharmacology, Toxicology, Endocrinology. 109(2):173-89, 1994 Oct.
8. Mustad VA. Kris-Etherton PM. Derr J. Reddy CC. Pearson TA. Comparison of the effects of diets rich in stearic acid versus myristic acid and lauric acid on platelet fatty acids and excretion of thromboxane A2 and PGI2 metabolites in healthy young men. Metabolism: Clinical & Experimental. 42(4):463-9, 1993 Apr.

   

           

Responses published this month Articles Responses EDUCATION Is chocolate good for you?       Norzeihan Jan Bappu, Alan Bagnall (September 2004) Ciron Sivathevan (September 26, 2004) Read this response EDUCATION Is chocolate good for you?       Norzeihan Jan Bappu, Alan Bagnall (September 2004) Ciron Sivathevan (September 26, 2004)       ciron1000@hotmail.com A short response: whilst it may be valid that drinking hot cocoa or eating the cocoa beans may have benefits for a person, it cannot really be said that eating the commercialised choocolates that we find in shops are good for us. The popular chocolates that many of us eating are added with extra ingredients - its quite rare nowadays for us to even eat plain chocolate on its own, companies usually load them up with extra ingredients. In addition to this, the commercialised chocolates are probably loaded with extra additives which cannot be good for us, and so the disadvantages from eating chocolate must outweigh the benefits that eating chocolate gives. In order for us to enjoy chocolate whilst also enjoying the benefits, we would have to invest extra money in importing pure cocoa chocolate, which is something that is highly unlikely to happen in MEDCs.