Researchers from the Polytechnic Institute of Coimbra in Portugal and the University of Gothenburg in Sweden found that study participants who ingested a ‘higher dose’ of dark chocolate over a 30-day period had significant improvements in brachial and central systolic and pulse pressures, markers of cardiovascular health.
The improvements noted among the high dose chocolate group was compared to study participants who ingested a lower dose of chocolate in the same time.
“This study demonstrated that regular consumption of high-cocoa chocolate has beneficial effects on the cardiovascular system in young, healthy adults, improving vascular function by reducing central brachial artery pressures and promoting vascular relaxation, and thus enhancing the matching of the arterial system with the left ventricle,” the researchers reported.
These results were published online earlier this year, due for printing in the August 2019 issue of the journal Nutrition.
What’s a high dose of chocolate?
The research team wanted to explore the health benefits of cocoa flavanols—compounds found in plants which have antioxidant effects to the human body.
“Although the benefits of cocoa on endothelial function are well documented in the general population, and in several clinical contexts, it is notoriously less representative in young, healthy populations,” the researchers wrote.
To investigate this, they compared the effects of ingesting two different types of chocolate. Both have similar nutritional ingredients, differing only in the percentage of cocoa and the amount of epicatechins. The high dose chocolate group ingested a 90% cocoa product, while the low dose group ingested a 55% cocoa product.
“The reduction of both diastolic and systolic blood pressures occurred in both groups, but was larger in the high cocoa chocolate group, thus indicating that a higher cocoa content, and thus higher amount of epicatechin, has a stronger ability to reduce blood pressure,” they reported.
Though health benefits associated with cocoa ingestion has motivated extensive research, the mechanisms of action are not yet completely identified.
Similarly, this current study only suggested a correlation between chocolate consumption and the changes in cardiovascular health markers. “The extent to which cocoa may interact with other healthy lifestyles strategies remains to be explored, and further research is needed to clarify the underlying mechanisms and to define optimal amounts of regular cocoa rich dark chocolate intake,” the researchers wrote.
This present study was conducted independently with no financing from external sources, the authors declared.
They looked at healthy participants between the ages of 18 and 35 recruited at the Polytechnic Institute of Coimbra. A standard lifestyle questionnaire was used to assess whether participants were eligible (moderate alcoholic beverage consumption, no allergy or intolerance to chocolate, and more).
Thirty eligible participants, both men and women, were randomly divided into two group, a high-cocoa group and a low-cocoa group. Both participants and researchers responsible for the clinical measurements were blinded to the type of chocolate each participant consumed.
At the beginning of the study, baseline measurements were collected, which included a heart ultrasonography, carotid-femoral pulse wave velocity analysis, and ventricular-arterial coupling analysis.
Participants ingested the assigned chocolate daily (20 g) for a period of 30 days, after which the same measurements were once again collected for the comparison.
Published online ahead of print, https://doi.org/10.1016/j.nut.2019.02.017
“Randomized study of the effects of cocoa-rich chocolate on the ventricle–arterial coupling and vascular function of young, healthy adults”
Authors: Telmo Pereira, et al.