"Dark chocolate", also called "plain chocolate" or "black chocolate", contains fat, sugar and minimum of 35% solid cocoa with no or very little milk. Dark Chocolate can be eaten as such or those with 70 – 99% of solid cocoa can be used in cooking. Couverture (semisweet and bitter dark chocolates) contains half and less than third as much sugar as cocoa respectively. [1]

Cocao beans contain two main health beneficial substances. They are polyphenols including flavonoids and tannins. Flavonoids are anti-oxidants, exhibit antihypertensive, anti-inflammatory, antithrombotic and metabolic effects. [2] Tannins interfere with action of bacteria on teeth and decrease the chances of dental cavities. [3]

Swedish Mammography Cohort Prospective cohort study of 31 823 women aged 48 to 83 years without baseline diabetes or a history of HF or myocardial infarction has shown that regular intake of dark chocolate decreased the rate of heart hospitalization or death. But this protective association was not observed with intake of ≥1 servings of chocolate per day. [4]

Baylor College of Dentistry suggests for few restrictions on consumption of dark chocolates. They are avoiding nibbing of dark chocolate all the day, limiting chocolate consumption to once or maximum of twice a day, consuming chocolate in moderation .i.e. one ounce of dark chocolate and brushing the teeth afterwards. Observing these precautions may help the population to harvest the beneficial effect of dark chocolate with very minimal adverse events if at all any. [3]

Prescribing dark chocolate may be beneficial public health measure. However, we need to simultaneously establish food hygiene by experimenting with suitable substitution of snacks and ascertain optimal quantity, frequency of dark chocolate consumption so as to keep the incidence of unwanted effects low.

References:
1. EUR-Lex Access to European Union law - ID celex 32000L0036: Directive 2000/36/EC of the European Parliament and of the Council of 23 June 2000 relating to cocoa and chocolate products intended for human consumption [online], 2000. Belgium. Europa. Available from http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32000L0036:E.... Accessed on 18 June 2012.
2. Lippi G, Franchini M, Montagnana M, Favaloro EJ, Guidi GC, Targher G. Dark chocolate: consumption for pleasure or therapy? J Thromb Thrombolysis. 2009 Nov;28(4):482-8.
3. HSC-BCD News Releases: Chocolate may be good for your teeth [online], February 2009. Dallas, Texas. Texas A & M Health Science Center – Baylor college of Dentistry. Available from http://www.bcd.tamhsc.edu/newsevents/newsreleases/chocolate.html. Accessed on 18 June 2012
4. E Mostofsky, E B Levitan, A Wolk,, M A Mittleman. Chocolate Intake and Incidence of Heart Failure: A Population-Based Prospective Study of Middle-Aged and Elderly Women. Circulation: Heart Failure. 2010; 3: 612-616

Competing interests: None declared

The consumption of chocolate beyond its role as a “pharmacological” agent appears to be influenced by psychological factors. It is now known that people who tend to score greater on depression scales consume significantly greater amount of chocolate than those without depression1. Thus, in contrast to the traditional drugs (which are aimed to reduce morbidity and mortality), chocolate use is influenced by the mood and other psychological factors of the patients. Hence, the authors might have over-estimated the $A40 (£25; €31; $42) cost attributed in reducing the cardiovascular events.

The Framingham algorithms were used to estimate the baseline risk of myocardial infarction and stroke (non-fatal cardiovascular events) as well as cardiovascular death2. The Framingham heart study enrolled healthy population in comparison with the present study where population with metabolic syndrome was studied. Hence, that algorithm might have under-estimated the cardiovascular events in people with metabolic syndrome.

We therefore believe that the use of dark chocolate for primary prevention of cardiovascular events may actually be more efficacious and cost-effective than that predicted in this study.

References:
1. Rose N, Koperski S, Golomb BA. Mood food: chocolate and depressive symptoms in a cross-sectional analysis. Arch Intern Med. 2010 Apr 26;170(8):699-703.
2. Anderson KM, Odell PM, Wilson PW, Kannel WB. Cardiovascular disease risk profiles. Am Heart J. 1991 Jan;121(1 Pt 2):293-8.

Competing interests: None declared

The authors list $42 as a pure cost. However, unlike medications which provide no benefit to patients beyond the hoped for reduction in non-fatal and fatal events, consumption of dark chocolate has intrinsic value to most patients. As a result, the cost attributed to the prevention strategy is too high and dark chocolate consumption should be even more cost effective than predicted by the authors.

Competing interests: None declared

In an era where we constantly here about the rising numbers of obese children and adults, as well as increasing consumption of high calorie food (which any form of chocolate), I fear this study will merely grab headlines for doctors encouraging the public to eat more. The authors acknowledge themselves that there are some assumptions made about the benefits of 100grams of chocolate to the health of individuals over 10 years, but in addition, one has to question the practicalities of this recommendation to a large proportion of the public that this would affect.

Many high risk patients come from low socio-economic groups. The cost of 100grams of dark chocolate would be substantial over the course of a year. Add to this the fact that most dark chocolate is produced by the more high quality end of the chocolate industry and a typical bar costs well over £1.50 and sometime £2. Some patients would only be spending just over this much on a whole days worth of food.

In addition, the study did not look at the practicalities of substituting the rest of the daily diet for this 100g consumption. In reality, if the 100grams is palatable the majority are going to add this to the diet, not substitute it. The study, far from solving some of our obesity and cardiovascular time bombs, seems to be adding to the weight of these problems on the health profession.

Competing interests: None declared