New research has found that a flavanol-rich cocoa beverage could benefit cardiovascular health, even after eating foods high in fat.
The results, which have been published in the journal Food and Function, highlight potential of naturally-occurring plant flavonols in protecting the heart from the negative impacts of a high-fat diet.
Exploring the impact of flavanol intake
There has been a significant uptick in the nutraceutical industry's knowledge on plant-based flavonoids and their benefits on health, so researchers at the University of Birmingham wanted to explore the potential impact of flavanols.
Flavanols are a specialised class of flavonoids that can be derived from a range of plant sources, and are considered to be highly bioactive.
Although they can be found in a range of herbs, fruits and nuts, scientists have found cocoa-derived products to be naturally high in flavanols, so the research team placed a focus on cocoa as a source.
Throughout the study, healthy adults were given a high-fat, dairy-based breakfast with cheese, butter and whole milk, which would be supplemented with either a high-flavanol or low-flavanol cocoa drink.
After a rest period post-breakfast, participants were asked to take a mental maths test, which aimed to mimic the stress an individual may experience in their daily life.
In both the rest and mental maths periods, forearm blood flow, cardiocascular activity and prefrontal cortex tissue oxygenation was measured to determine the impact of flavanols on overall vascular flow.
The team also measured each participant's vascular function using brachial flow-mediated dilatation (FMD) — a prognostic measure used to assess an individual's risk of cardiovascular disease.
Flavanols as a mitigative functional ingredient
After running this experiment, researchers found that those given high-flavanol cocoa experienced a heightened brachial flow-mediated dilation compared to the low-cocoa arm.
This was observed both 30 and 90 minutes after the stressful period, and highlights the potential of flavanol supplementation in preventing the decline in vascular function associated with stress and fat consumption.
In previous studies, the research team at the University of Birmingham also found that eating foods high in fat could reduce cerebral oxygenation in the pre-frontal cortex during stress, though cocoa flavanols didn't improve cerebral oxygenation in this study.
Non-alkalised flavanols necessary for the job
According to, Rosalind Baynham, first author on the paper, "Flavanols are a type of compound that occur in different fruits, vegetables, tea and nuts including berries and unprocessed cocoa. Flavanols are known to have health benefits, particularly for regulating blood pressure and protecting cardiovascular health."
However, cocoa powders that have been alkalised have a highly reduced level of flavanols, so these powders will not benefit a user nearly as much as their unprocessed counterparts.
In this study, researchers found that the alkalised powder variation contained 5.6mg of flavanols per serving, whereas the non-alkalised powder contained 695mg per serving.
Alkalisation is commonly used to enhance the flavour of chocolate, but in the process, it often breaks down the natural bioactive substances found in cocoa — with flavanols being one of them.
The current recommended intake for flavanols in one day is 400–600mg per day.
Dr Catarina Rendeiro, Assistant Professor in Nutritional Sciences at the University of Birmingham, commented: “This research shows that drinking or eating a food high in flavanols can be used as a strategy to mitigate some of the impact of poorer food choices on the vascular system. This can help us make more informed decisions about what we eat and drink during stressful periods.”
Jet Veldhuijzen van Zanten, Professor of Biological Psychology at the University of Birmingham, and author of this paper added: “Modern life is stressful and the impact of stress on our health and the economy has been well documented, so any changes we can make to protect ourselves from some of the symptoms of stress is positive. For those who tend to reach for a treat when stressed or depend on convenient food because they work high-pressure jobs or are time-poor, incorporating some of these small changes could make a real difference.”