Tea and the Relationship with Cardiovascular Disease

 

Cardiovascular disease is a leading cause of death worldwide, and tea is one of the most widely consumed beverages globally, as well as a primary source of caffeine for adults. The habit of drinking tea originated in China thousands of years ago, but since then, it has spread worldwide. Evidence from observational and randomized controlled studies suggests that green tea has many potential benefits in reducing the risk of cardiovascular disease, including reducing the risk of major cardiovascular events, lowering blood pressure, lowering low-density lipoprotein cholesterol (LDL-C) levels, and aiding in weight loss.

At the same time, the physiological mechanisms by which tea provides cardiovascular benefits are continually being investigated. Many studies have found that the main component of tea that provides cardiovascular protection is tea polyphenols, primarily catechins. Clinical evidence shows that drinking tea can reduce the risk of coronary heart disease, heart failure, arrhythmias, stroke, cardiovascular disease, and all-cause mortality. In population-based studies, higher tea intake, particularly three cups of green tea per day, is associated with improved cardiovascular outcomes.

Research has found that cardiovascular disease is the leading cause of death worldwide, with approximately four million deaths from cardiovascular disease in 2017, accounting for one-quarter of all deaths. In China, coronary heart disease and stroke have also become the two leading causes of death. Therefore, how to prevent cardiovascular and cerebrovascular diseases through daily diet has been a pressing issue. The idea of drinking tea for health has been circulating in society for a long time, and countries such as the United States and Japan have conducted research indicating that moderate tea consumption can reduce the incidence of cardiovascular disease and overall mortality. However, due to differences in tea-drinking culture, lifestyle habits, and disease spectrum, this conclusion cannot be directly applied to the Chinese population.

Tea, especially green tea, is a rich source of flavonoids, including epicatechin, catechin, and epigallocatechin-3-gallate. Mechanism studies have shown that these bioactive compounds can alleviate oxidative stress, relieve inflammation, and enhance endothelial and myocardial cells. Observational studies and randomized controlled trials also indicate that these bioactive compounds can alleviate risk factors for coronary heart disease, including hypertension and dyslipidemia. In contrast, tea polyphenols in black tea are oxidized into pigments during the fermentation process, resulting in weaker associations with health benefits.