Cocoa Flavanols Reduce Hypertension and Increase Blood Vessel Function in Healthy People

14 Sep 2015 --- Two recently published studies in the journals Age and the British Journal of Nutrition (BJN) demonstrate that consuming cocoa flavanols improves cardiovascular function and lessens the burden on the heart that comes with the ageing and stiffening of arteries. The studies also provide novel data to indicate that intake of cocoa flavanols reduces the risk of developing cardiovascular disease (CVD).

Arterial stiffness and blood vessel dysfunction are linked with cardiovascular disease -- the number one cause of deaths worldwide. "With the world population getting older, the incidence of cardiovascular disease, heart attacks and stroke will only increase," says Professor Malte Kelm, Professor of Cardiology, Pulmonary Diseases and Vascular Medicine at University Hospital Düsseldorf and Scientific Director of FLAVIOLA. "It is therefore pivotal that we understand the positive impact diet can have on cardiovascular disease risk. As part of this, we want to know what role flavanol-containing foods could play in maintaining the health of the heart and blood vessels."

Cocoa flavanols are plant-derived bioactives from the cacao bean. Dietary intake of flavanols has been shown to have a beneficial effect on cardiovascular health but the compounds are often destroyed during normal food processing. Earlier studies have demonstrated that cocoa flavanol intake improves the elasticity of blood vessels and lowers blood pressure -- but, for the most part, these investigations have focused on high-risk individuals like smokers and people that have already been diagnosed with conditions like hypertension and coronary heart disease. These two studies in Age and BJN are the first to look at the different effects dietary cocoa flavanols can have on the blood vessels of healthy, low-risk individuals with no signs or symptoms of cardiovascular disease.

In the study published in Age, two groups of 22 young (<35 years of age) and 20 older (50-80 years of age) healthy men consumed either a flavanol-containing drink, or a flavanol-free control drink, twice a day for two weeks. The researchers then measured the effect of flavanols on hallmarks of cardiovascular aging, such as arterial stiffness, blood pressure and blood vessels dilation.

They found that vasodilation was significantly improved in both age groups that consumed flavanols over the course of the study. In the older age group, a statistically and clinically significant decrease in systolic blood pressure was also seen, improving cardiovascular health and lowering the risk of CVD

"We found that intake of flavanols significantly improves several of the hallmarks of cardiovascular health in just 4 weeks," says Professor Kelm. The researchers also calculated the Framingham Risk Score - a widely used model to estimate the 10-year cardiovascular risk of an individual - and found that flavanol intake reduced the risk of CVD. "Our results indicate that dietary flavanol intake reduces the 10-year risk of being diagnosed with CVD by 22% and the 10-year risk of suffering a heart attack by 31%," says Professor Kelm.

The combined results of these studies demonstrate that flavanols are effective at mitigating age-related changes in blood vessels, and could thereby reduce the risk of CVD in healthy individuals. The application of 10-year Framingham Risk Scores should be interpreted with caution as the duration of the BJN study was weeks not years and the number of participants was around 100, not reaching the scale of the Framingham studies. That being said, Professor Kelm comments that "the reduction seen in risk scores suggests that flavanols may have primary preventive potential for CVD." Other longer-term studies are now underway to investigate the health potential of flavanols on a much larger scale.