Dark Chocolate and Cardiovascular Health

A Mendelian randomization study published in Scientific Reports found that dark chocolate intake was associated with a reduced risk for essential hypertension (EH). Essential hypertension is high blood pressure (BP) that does not have a known cause.

The results also indicate that dark chocolate consumption may reduce blood clot risk, but researchers could not establish a causal relationship.

"In the study, based on defined criteria for significant causality, we found that genetically predicted dark chocolate consumption was associated with a lower risk of essential hypertension but not with heart failure, coronary heart disease, myocardial infarction, atrial fibrillation, non-rheumatic valvular heart disease, stroke, non-ischemic cardiomyopathy, DVT of the lower extremities, ischemic stroke, and transient ischemic attack (TIA)," the researchers reported.

High blood pressure can have serious implications for cardiovascular health. Prevention and management of high BP can help ensure many positive health outcomes, but researchers are still looking to understand the best methods for preventing high blood pressure.

Dark chocolate is a popular food item that may offer valuable health benefits. Previous intervention studies have revealed some benefits of dark chocolate for the cardiovascular system, but it has not been established whether dark chocolate intake is associated with the risk of cardiovascular diseases (CVDs). Therefore, Weiliang Tang, Shaoxing People’s Hospital, Shaoxing, Zhejiang, People’s Republic of China, and colleagues aimed to investigate the causality between dark chocolate intake and the risk of cardiovascular disease by conducting a Mendelian randomization (MR) study.

For this purpose, they obtained summary-level data on dark chocolate intake and CVD from publicly available genome-wide association studies. In the MR study, the main approach was using a fixed-effect model with inverse variance weighted (IVW) and evaluating the robustness of the results via sensitivity analysis.

Key Findings of the Study:

• Dark chocolate intake was significantly associated with the reduction of the risk of essential hypertension (OR = 0.73), as well as with the suggestive association with the reduced risk of venous thromboembolism (OR = 0.69).
• No association was found between dark chocolate intake and the other ten CVDs.

"The two-sample MR study revealed causality between dark chocolate intake and reduced essential hypertension risk," the researchers wrote. "However, the causality with venous thromboembolism could not be established due to insufficient evidence, and there is no causality observed with other CVDs."

"Our findings have some implications for the prevention of EH in the population," they concluded, adding that, "there is a need for further clinical research to explore the causality between dark chocolate intake and CVD risk."

Reference:

Yang, J., Zhou, J., Yang, J., Lou, H., Zhao, B., Chi, J., & Tang, W. (2024). Dark chocolate intake and cardiovascular diseases: A Mendelian randomization study. Scientific Reports, 14(1), 1-9. https://doi.org/10.1038/s41598-023-50351-6