A study presented this week at the European Society of Cardiology (ESC Congress) suggested dark chocolate enriched with 10% extra virgin olive oil may reduce the risk of cardiovascular disease.
However, any commercial product will not be able to be marketed as ‘chocolate’ in Europe.
Not chocolate in Europe
Lead author Dr Rossella Di Stefano of the University of Pisa said commercial prospects were strong since private partner of the research team – Italian chocolate maker Vestri Cioccolato - has already commercialized an olive oil chocolate product with “good results”.
“The problem arises about the use of the term ‘chocolate’, which, at the moment, is impossible since extra virgin olive oil is not included among the vegetable fats usable for chocolate production [under Directive 2000/36/EC],” she said.
The research team at the University of Pisa, the Institute of Life Sciences in Pisa and the University of Siena explored the effects of extra virgin olive oil (EVOO) enriched 70% cocoa dark chocolate compared to dark chocolate enriched with Panaia red apple.
Study design and results
A test group of 30 adults with at least three cardiovascular risk factors – such as being a smoker, being overweight or having a family history of cardiovascular disease – were randomly assigned to eat a solid 40 g dark chocolate bar with either 10% EVVO or 2.5% dry apple daily for 28 days.
The researchers compared urine, blood samples, body mass index and blood pressure among other tests at baseline to results after the study.
They found EVVO chocolate was more effective in reducing cardiovascular risk factors.
Those who ate EVVO chocolate showed a decrease in HDL 'good' cholesterol and a moderate decrease in blood pressure compared to pre-intervention levels.
The EVO-dark chocolate group also showed a significant increase in circulating EPC levels –a factor believed to reduce the risk of cardiovascular disease - compared to the apples group.
The researchers said extra polyphenols in EVVO may be responsible.
How does it taste?
Dr Di Stefano said of EVVO chocolate: “The color does not change much, but changes the appearance: The bar looks very smooth and bright. When in the mouth, comparing to the regular dark chocolate, the process of liquification is a bit faster and the oil/cocoa fills the oral cavity giving a sense of nice smoothness without any lack of saliva. “
She said the taste is more complex than regular dark chocolate with a more intense bitterness, based on consumer tests.
“In general, our consumer test showed how the product with olive oil was not liked by old people, consuming sweet or milk chocolate, while it was liked the most by young people, with high school degrees, interested in food of good quality and familiar to other tasting experiences,” she said.
Benefits from cocoa flavanols or olive oil?
The study did not test EVVO chocolate against a regular 70% cocoa dark chocolate bar.
So how do they know the cardiovascular benefit was not coming mainly from cocoa flavanols in the dark chocolate?
Dr Di Stefano said: “The ‘apple-fortified dark chocolate’ has a very small percentage of dry apple (2.5%) and with the significant difference in the improvement in the number of endothelial progenitor cells and endogenous metabolism with the EVOO–enriched ‘chocolate’, we can suppose the apple chocolate could act as just dark chocolate and the different polyphenols of EVOO might explain the difference.”
She added since the research team only tested 10% EVVO addition, “I can’t exclude that different (lower or higher) percentage might improve or change the clinical results”.
Italian chocolate maker Vestri sells a selection of EVVO-enriched dark ‘chocolate’ product named Toscolata. Its 120 g bar retails for €11 ($13) on its website.
‘Extra virgin olive oil and apples enriched-dark chocolate consumption and endothelial function: a randomized crossover trial in patients with cardiovascular risk factors’
European Society of Cardiology
Authors: R. Di Stefano, F. Felice, E. Belardinelli, V. Di Bello, V. Domenici, M. Cifelli, L. Sebastiani, A. Francini , M. Romi , G.Cai, C. Cantini