A study published in American Journal of Clinical Nutrition adds to the body of data demonstrating that bioactive compounds found in cocoa can keep the heart healthy – although two types of ‘bioactives’ called flavanols and procyanidins behave differently in the body.
The study found that healthy adults experienced improved blood vessel function along with improvements in blood pressure, arterial stiffness, and cholesterol after one month of once-daily consumption of an extract enriched in flavanols and procyanidins.
Only the group that consumed flavanols and procyanidins together experienced all benefits. The group that consumed the procyanidin-enriched extract only experienced a reduction in total cholesterol.
Consequently, improvements in blood vessel function, blood pressure, and arterial stiffness were shown to predominantly relate to the intake of flavanols, but not to the intake of the more abundant procyanidins and their gut microbiome-derived metabolites.
Bioactives are dietary compounds that can be beneficial to health. Comprised of two kinds of bioactives, namely flavanols and procyanidins, the cocoa flavanols present in cocoa have attracted considerable scientific attention in recent years.
As both groups of compounds are also found in apples, grapes, berries, and some cereals and legumes, the use of cocoa extract as a model for flavanol- and procyanidin- containing foods is likely to generate insights relevant beyond cocoa.
Multiple studies have shown that daily consumption of flavanols and procyanidins has led to improved blood pressure, cholesterol and the flexibility of blood vessels. But until now, it was less clear to what extent flavanols and procyanidins respectively contribute to the observed benefits, and whether or not they act synergistically. A paper published this week in AJCN by an international team of researchers, including scientists from Mars, Incorporated, is the first to begin to directly answer this question.
“We were able to confirm previous findings related to cocoa flavanols, and we gained novel insights into the respective contributions of flavanols and procyanidins in the context of their cardiovascular effects in humans. We found that the flavanols, especially (−)-epicatechin, represent the bioactives primarily responsible for the beneficial vascular effects observed after cocoa flavanol intake,” said Christian Heiss, a clinical professor based at the University of Surrey and Surrey and Sussex Healthcare NHS Trust, and one of the researchers in the study. “Only the group taking 130 mg of (−)-epicatechin experienced both the acute and long-term beneficial effects related to flavanol and procyanidin intake.”
Acute responses included improvements in the ability of blood vessels to dilate. Long-term responses included improvements in blood pressure and arterial stiffness. The groups taking either a placebo or the low-epicatechin capsules experienced no significant changes in any of the above endpoints.
“Although procyanidins did not directly improve blood vessel dilation, blood pressure or arterial stiffness, their intake did have a beneficial effect on blood lipids,” continued Dr Heiss. “Both groups taking capsules that contained procyanidins had a reduction in total cholesterol compared to the placebo control group after one month.”
The study also looked at what happens to flavanols and procyanidins after they are consumed and enter the body. The results confirmed findings from earlier investigations, showing that flavanols and procyanidins are broken down by the microbiota in the human gut, resulting in the formation of compounds called gamma-valerolactones.
Although gamma-valerolactones were proposed to be bioactive, and potentially involved in mediating the cardiovascular benefits observed following the intake of flavanols and procyanidins, the study could not provide evidence in support of this notion.
Gamma-valerolactones appeared not to be directly involved in mediating improvements in blood vessel dilation, blood pressure, and vascular stiffness, and thus appear not to be bioactive in the context of these cardiovascular effects. Procyanidins are more likely to have important indirect effects by protecting flavanols within a food during food processing as well as in the gastrointestinal tract from degradation and inactivation.
“Compared to other bioactives, we know quite a lot about cocoa flavanols today, but this study provides new and important insights,” said Dr Heiss. “It is critical to understand how these bioactives interact with each other and with the human body, in order to create a comprehensive basis for evidence-based recommendations about how much of these compounds, or the foods that contain them, people should be consuming for health maintenance and disease risk reduction.”
As we age, blood pressure, cholesterol, and stiffness of arteries increase. What is important is that they are each independently associated with an increased risk of cardiovascular disease and death. Consuming procyanidins and flavanols, like (−)-epicatechin, could therefore help people maintain their heart health.
The study was published in the American Journal of Clinical Nutrition and is freely available on their website here: