One area of interest is how a component of cocoa—specifically cocoa flavanols—may impact blood pressure and arterial stiffness.
The health of the heart and blood vessels is critical to overall well-being. The heart pumps blood throughout the body, providing it with the oxygen and nutrients it needs to function. Researchers are constantly examining factors that impact and improve cardiovascular health.
A recent study published in Frontiers. found that cocoa flavanols can effectively lower blood pressure in people with ideal blood pressure, but not when it was already low, as well as reduce arterial stiffness.
The Centers for Disease Control and Prevention (CDC) notes that high blood pressure, unhealthy cholesterol levels, and obesity can all increase someone’s risk for developing heart disease.
Controlling these factors, such as through medications and lifestyle changes, can help improve cardiovascular health and reduce the risk for more severe health problems. However, the intervention plan will look different for each person. Healthy individuals can take specific health steps to reduce their chances of developing certain risk factors such as high blood pressure.
The CDC states that high blood pressure is a major risk factor for heart disease, and says it is considered the ‘silent killer as there is no way to know you have it other than to measure your blood pressure.
The National Heart, Lung, and Blood Institute notes that people can lower their blood pressure “with lifestyle changes such as eating healthy, staying active, and watching your weight” to reduce their risk of developing heart disease and experiencing a heart attack. They also advise those concerned about their blood pressure to talk with healthcare professionals about ways to control it.
Researchers of the current study note that previous controlled clinical intervention studies have demonstrated the blood pressure-decreasing and arterial stiffness-reducing effects of cocoa flavanols (CF) in healthy humans.
However, as these studies were in tightly controlled settings, the researchers wanted to see how well this intervention played out in real-life scenarios. The researchers used an n-of-1 study design, where a small number of participants were exposed to the same intervention or the placebo multiple times. They then compared the results for each individual as well as between individuals.
The study included eleven healthy adults who received alternating doses of cocoa flavanol capsules and placebo capsules for eight days. They received the doses at the same time in the morning after the baseline collection of blood pressure, heart rate, and pulse wave velocity which they had been shown how to do using a blood pressure cuff and a finger clip for the first two days, and then entered data into an iPod touch on their own. Researchers use pulse wave velocity to measure arterial stiffness.
The participants took these measurements every half hour for the first three hours after taking the capsule and then hourly for twelve hours throughout the day.
The results showed that cocoa flavanols were effective in lowering blood pressure and reducing arterial stiffness.
One concern about using cocoa flavanols to lower blood pressure is the risk of the blood pressure dropping too low. However, in this study, researchers found that the cocoa had less impact when blood pressure was lower, indicating it was a potentially safe intervention.
The study adds to growing evidence of the effectiveness of cocoa flavanols in improving cardiovascular health. However, the study authors did note a few limitations and implications.
First, the study had a small sample size, researchers did not collect blood samples, and dietary influences on results were not evaluated. They also note that the cocoa supplements also included methylxanthines, which can impact health. However, based on their research, they believe that the effects of the intervention were due to the cocoa flavanols. The devices they used in the study had to be manually activated, which limited some data collection and made implementing this kind of monitoring in everyday life unlikely.
Researchers note that the increase in heart rate found among participants must be considered a potential side effect. This increase could mask the effects of lowered blood pressure. They also noted that it’s unclear why cocoa flavanols improve components like arterial stiffness, and further research could focus on this mechanism. The participants’ responses also varied, so developing individualized treatment methods for cardiovascular health will be essential.
Prof. Heiss explained that future research could focus on the “Development of personal health monitoring devices and accessible biomarkers of health to allow people to effectively improve their health.” Furthermore, Prof. Heiss said that experts could also seek to “Evaluate if cocoa flavanols and other bioactive can improve the health of patients and how they can be effectively incorporated in the medical management together with or instead of drugs.”
Parvathy Sukumaran 
