Science Media CentreTuesday 30 August 2011, 2:34PM
Media release from Science Media Centre
High levels of chocolate consumption might be associated with a one
third reduction in the risk of developing heart disease, according
to a new study. However the authors and independent experts urge
caution in the interpretation of the
The research, to be published today in the British Medical Journal,
analysed data from previous studies that examined chocolate
consumption and various cardiovascular and metabolic
The findings confirm results of existing studies that generally
agree on a potential beneficial link between chocolate consumption
and heart health. However, the authors stress that further studies
are needed to test whether chocolate actually causes this reduction
or if it can be explained by some other unmeasured (confounding)
A full press release and a copy of the study is available in the
SMC Resource Library.
The Science Media Centre contacted New Zealand experts for comment.
Feel free to use these quotes in your stories. To talk to a local
expert, please contact the SMC.
Dr Alexandra Chisholm, Senior Lecturer / Research Dietitian,
Department of Human Nutrition, University of Otago said:
"The article does not differentiate between types of chocolate
whereas the interventions & studies looking at mechanisms of
action use high cocoa solids chocolate.
"As these are cohort, case-control, and cross sectional studies
they can not show causality only indicate possible areas of further
research. Further the authors state "Large
variation was observed between these seven studies for measurement
of chocolate consumption, methods, and outcomes
"This is a problem as beneficial effects may be related to
frequency /infrequency of consumption & there may also be a
gender specific effects which, were not able to be measured in this
"The authors selected studies in which "chocolate consumption was
assessed by a validated tool" however from this food frequency
questionnaire (FFQ) it would appear that they used "a single item
from the food frequency questionnaire that asked about consumption
of chocolate bars, snacks, or pieces" (this is unclear) thus other
possibly confounding dietary factors would not have been
captured. Did those in the highest chocolate
consumption category have a better overall dietary
"The FFQ included chocolate drinks which may have indicated a
higher consumption of milk. Some other dietary factors have been
adjusted for (Table 2) but one wonders how these were
measured. One study reviewed (Mink et al 2007) measured
flavonoid intake & only adjusted for energy consumption so one
could assume that chocolate was only one item measured.
"The authors "necessary cautions" and relatively cautious
conclusions are appropriate however it is not clear that reducing
the amount of fat & sugar in commercially available chocolate
will transform it into a more beneficial food. However the
use of minimally processed, higher cacao products in developing
countries may have some merit."
The following quotes are from our friends at the UK Science Media
Prof Tom Sanders, Professor of Nutrition & Dietetics
and Head of the Diabetes & Nutritional Sciences Division,
School of Medicine, King's College London, said:
"The problem on chocolate consumption is underreporting by
overweight individuals; they under report food intake, especially
forbidden foods such as chocolate. There is a chocolate gap - more
chocolate is sold than people own up to consuming.
"Cocoa butter, although a rich source of saturated fatty acids,
does not raise cholesterol much because the major saturated fatty
acid in it is stearic acid, which neither raises nor lowers
cholesterol. The evidence regarding chocolate and blood pressure is
mixed, with a recent study showing that cocoaflavonoids increase
"The main problem with chocolate is overindulgence and calories. A
little bit of chocolate is OK but the mega-slabs offered cheaply
are fuelling obesity in the overweight."
Victoria Taylor, Senior Heart Health Dietitian at the
British Heart Foundation, said:
"Evidence does suggest chocolate might have some heart health
benefits but we need to find out why that might be.
"We can't start advising people to eat lots of chocolate based on
this research. It didn't explore what it is about chocolate that
could help and if one particular type of chocolate is better than
"If you want to reduce your heart disease risk, there are much
better places to start than at the bottom of a box of chocolates.
You can still eat chocolate as part of a balanced diet but
moderation is key because this sweet treat is usually packed with
saturated fat and calories."
Catherine Collins, Dietician at St
George's Healthcare NHS Trust, said:
"Most chocolate we eat is milk chocolate, which in this country is
different to continental milk chocolate in the amount of vegetable
versus milk fat we blend with cocoa to give it its '30%/ 45% cocoa
solids" definition. Also, white chocolate is a totally
different product altogether so can't be compared with brown
chocolate with regards to flavonoid content. Cocoa butter
does not appear to raise cholesterol, due to it stearic and oleic
acid contents, but of course the sugar content of the final item
could raise triglycerides but the results seem to suggest any
clinical consequence of this is negligible.
"This paper doesn't really say eat chocolate to improve heart
health - nor do the authors conclude this either. What they
seem to say is, those who don't deny themselves a sweet treat of
choc - white or brown - have better cardiovascular outcomes.
I do feel that the perceived relaxing effect of chocolate (which is
recorded in studies as being as soon as the taste and 'mouthfeel'
of choc is experienced, before the product has hit the intestine
and contributed to blood levels of sugar/serotonin whatever) is a
contributor - perhaps akin to modest alcohol consumption - a
relaxing treat, perceived as a 'de-stressor' and a food whose cost
base is so low it's affordable by virtually all.
"In terms of UK chocolate, it has to be based on relaxation rather
than nutritional content, as our fancy-and-filled product ranges
(think Crunchie, Mars bar, Topic, Turkish Delight) contain such
little actual chocolate per unit, and what is there is mainly milk
choc with low cocoa solids, that this cannot be solely attributed
to cocoa flavonoids alone. For more information see
"So, it's better for general health to relax and enjoy all foods,
rather than be one of the food fascists I regularly meet who will
'eat four squares of high quality organic dark chocolate and three
brazil nuts a day' for the heart and selenium benefits
respectively. (Perhaps a chocolate brazil would do the same
Study 'Chocolate consumption and cardiometabolic disorders:
systematic review and meta-analysis', Adriana Buitrago-Lopez et al,
BMJ 2011;343:d4488 doi: 10.1136/bmj.d4488 will be
published in the BMJ at 09.10am UK time Monday 29 August