Craving chocolate? Go ahead and grab a few pieces. A number of recent studies have found that compounds in cocoa called flavanol could improve cardiovascular health and reduce blood pressure.
In a study published in the Journal of Nutrition, a systematic review and meta-analysis of 19 randomized controlled trials called for serious and long-term studies to show how the short-term benefits of cocoa flavanol intake translate into improved clinical outcomes.
In the published meta-analysis, the team of researchers evaluated 19 randomized controlled trials (RCT), involving 1,139 volunteers, that observed whether or not the intake of flavanol-rich cocoa products improved circulating biomarkers of cardiovascular metabolism.
Biomarkers of metabolism are measurable compounds like triglycerides, lipoproteins and insulin that are produced by normal metabolism. Quantifying the levels of these different cardiovascular metabolism biomarkers gives scientists and physicians a way of understanding which aspects of people’s metabolism is working or not working.
By understanding which biomarkers of cardiovascular metabolism are affected by cocoa’s flavanols, scientists can start to strategize on how to use cocoa flavanols to prevent the metabolic disorders like diabetes or cardiovascular disease.
“Our meta-analysis of RCTs characterizes how cocoa flavanols affect cardiometabolic biomarkers, providing guidance in designing large, definitive prevention trials against diabetes and cardiovascular disease in future work,” corresponding author Dr. Simin Liu, professor and director of the Center for Global Cardiometabolic Health at Brown University, said in a press release. “We found that cocoa flavanol intake may reduce dyslipidemia (elevated triglycerides), insulin resistance and systemic inflammation, which are all major subclinical risk factors for cardiometabolic diseases.”
While the results are encouraging, there are a few aspects of the meta-analysis to be cautious of. All of the studies were small and occurred over a short time period.
Additionally, not all biomarkers recorded in these studies changed for the better and none of the studies directly tested whether cocoa flavanol consumptions leads to reduced risk of heart disease or diabetes.
The statistically significant results showed the greatest effects were see in volunteers that consumed between 200 and 600 milligrams of flavanols a day. Researchers found declines in blood glucose and insulin, as well as a decline in HOMA-IR, an indicator of insulin resistance. Researchers also saw an increase in HDL cholesterol or “good” cholesterol.
Volunteers who ingested higher amounts of flavanols experience insulin resistance benefits and a drop in triglycerides but not a significant increase in HDLs. In general, the results were relevant for both men and women and did not depend on the physical form of flavanol-rich cocoa consumption, such as dark chocolate versus a drink.
The authors concluded in the press release that their research “highlights the urgent need for large, long-term RCTs that improve our understanding of how the short-term benefits of cocoa flavanol intake on cardiometabolic biomarkers may be translated into clinical outcomes.”
