A study published within the journal Scientific Reports shows that dark chocolate intake can significantly reduce the chance of essential hypertension. Essential hypertension refers to hypertension that’s multi-factorial and doesn’t have a definite cause.
Cardiovascular diseases are the leading explanation for disability and mortality worldwide and are major contributors to the worldwide disease burden. The estimated total variety of heart problems cases was 523 million in 2019, with the Middle East and North Africa having the very best prevalence and Central Asia and Eastern Europe having the very best mortality.
Given the high morbidity and mortality related to cardiovascular diseases, several studies have been conducted to discover each risk aspects and preventive measures. Some small-scale randomized controlled trials have shown that dark chocolates profit cardiovascular health. The most important three flavanols present in dark chocolate, including procyanidin, catechin, and epicatechin are known to have helpful effects on the cardiovascular system.
On this study, scientists have explored the causal relationship between dark chocolate intake and heart problems risk using the Mendelian randomization method. Mendelian randomization uses measured variation in genes of known function to look at the causal effect of a modifiable exposure on disease in observational studies.
The scientists obtained genome-wide association study summary-level data for dark chocolate intake from the MRC Integrative Epidemiology Unit (University of Bristol) website. The information included 64,945 European ancestry participants. They identified 21 independent single nucleotide polymorphisms as genetic instrumental variables for predicting dark chocolate intake. An instrumental variable is a sort of variable that shouldn’t be presupposed to have any direct effect on the end result.
Moreover, the scientists obtained summary-level data for cardiovascular diseases from various publicly available genome-wide association studies. They synchronized the datasets for dark chocolate intake and cardiovascular diseases to align the direction of alleles of the one nucleotide polymorphisms for each.
Then, they analyzed the information to find out the causal relationship between genetically predicted dark chocolate intake and risks of 12 cardiovascular diseases, including heart failure, coronary heart disease, myocardial infarction, atrial fibrillation, non-rheumatic valve disease, non-ischemic cardiopathy, essential hypertension, venous thromboembolism, deep vein thrombosis, stroke, ischemic stroke, and transient ischemic attack. Additionally they conducted sensitive analyses to evaluate the robustness of the Mendelian randomization evaluation results.
The study findings revealed that dark chocolate intake significantly reduces the chance of essential hypertension. A suggestive negative association between dark chocolate intake and the chance of venous thromboembolism was observed within the study. No significant association with dark chocolate intake was observed for other tested cardiovascular diseases.
This study reveals that genetically predicted dark chocolate intake is significantly related to a lower risk of essential hypertension and suggestively related to a lower risk of venous thromboembolism.
Available evidence indicates that flavanols present in dark chocolates can improve endothelial function, promote vasodilation, and forestall platelet aggregation by increasing nitric oxide release. Flavanols are also known to have potent antioxidant and anti inflammatory activities. All these activities of flavanols are believed to be the most important contributing aspects towards a healthy cardiovascular system.
The hypertension data utilized in this study includes cases of secondary hypertension, which is basically the manifestation of kidney disease, renal vascular disease, and a few endocrine diseases within the cardiovascular system. Nevertheless, the study doesn’t investigate any causal relationship of those diseases with dark chocolate intake. Thus, the scientists advise that folks shouldn’t rely only on dark chocolate to forestall essential hypertension. Slightly, people at high risk for essential hypertension can replace unhealthy snacks with dark chocolate to enhance their cardiovascular health.
As mentioned by the scientists, a small sample size of the exposure data was utilized in this study. The identified single nucleotide polymorphisms also failed to achieve the traditional genome-wide significance threshold. Nevertheless, these single nucleotide polymorphisms could be regarded as effective instrumental variables as their Fisher-statistic (a measure of the ratio of variances) values are greater than 10. A Fisher-statistic value of greater than 2.5 is required to reject the null hypothesis. Furthermore, the findings of sensitive analyses showed the robustness of the estimated causal effects for just about all outcomes.
Summer-level data of European ancestry populations was utilized in this study. This restricts the generalizability of study findings to other populations.
Overall, the study provides useful information for the prevention of essential hypertension in the overall population. More clinical research is required to firmly establish the causal relationship between dark chocolate intake and the chance of cardiovascular diseases.