New research has shown that regular tea consumption can protect against arterial stiffness in the heart – a condition that’s been linked to a shortened lifespan and higher risk of cardiovascular disease.
The study, which looked at habitual and non-habitual tea-drinkers in China, found that those who have been drinking tea regularly for six years or more had the lowest levels of arterial wall thickening and loss of elasticity, and adds to a growing body of evidence that tea consumption is likely doing great things for your heart health.
The team of medical doctors, led by cardiologist Qing-fei Lin from Wuyishan Municipal Hospital in China, surveyed 5,006 male and female people aged 40 to 75 in the local Fujian Province. Of those, 1,564 (31.2 percent) said they were habitual tea-drinkers – defined in the study as having consumed tea once or more per week for at least 12 months.
The subjects were split into four sub-groups: those who have been consuming tea habitually for more than 10 years; habitual tea-drinkers with 6-10 years under their belt; habitual tea-drinkers for 1-5 years; and non-habitual tea-drinkers.
The researchers measured the brachial-ankle pulse wave velocity (ba-PWV) of their subjects to determine arterial stiffness in both the aorta and peripheral artery of the heart. After adjusting for various lifestyle factors, they found that as the duration and the daily amount of habitual tea consumption increased, the average ba-PWV decreased, which means lower arterial stiffness.
Characterised by arterial wall thickening and loss of elasticity in both structural and cellular elements of the heart, arterial stiffness has been shown to be apredictor of total mortality and future cardiovascular disease, including heart failure and stroke. You want your arteries to be as flexible as possible to allow for easier blood flow so your heart doesn’t have to work so hard.
Habitual tea consumption may have a protective effect against arterial stiffness, especially for subjects who have habitually consumed tea for more than six years and more than 10 grams daily,” as the team concludes in the Journal of the American College of Nutrition.
The researchers suspect that the protective effect is due to a chemical reaction that occurs in the endothelial cells inside our arteries when they come into contact with chemicals called catechins – a kind of flavonoid – that are found abundantly in tea (green tea in particular).
Flavonoids in tea are helpful to relax the blood vessels. Catechins release nitrous oxide and cause [arteries] to be more compliant,” according to Stephen Devries, a preventive cardiologist at Northwestern University.
While the study, which has been published in the Journal of the American College of Nutrition, is limited by the fact that it relies on self-reporting participants to be truthful about their tea consumption history, and focuses only on participants living in a particular region of China, the results reflect what’s been found in previous studies from around the world.
There’s still a whole lot we don’t know about how different types of flavonoids in the things we eat and drink are affecting our health, but research is showing that a cup of tea or two per week week is a pretty good bet if you want to do something healthy for your heart.