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Tea is the most widely consumed drink in the world after water, and for centuries people have sipped it for comfort and refreshment. In recent decades, researchers have also become interested in how a daily cup might fit into a heart-healthy lifestyle. If you are new to the subject, this guide explains the basics in plain language.
What counts as "tea"?
True tea comes from the leaves of one plant, Camellia sinensis. Green, black, white and oolong teas all come from this same plant. The differences come from how the leaves are processed after picking. Green tea is heated soon after harvest so the leaves stay green, while black tea is allowed to oxidize, which darkens the leaves and changes the flavor.
Herbal "teas" such as chamomile, peppermint, hibiscus and rooibos are not made from the tea plant at all. They are infusions of other plants, so they contain different natural compounds. Many are pleasant and caffeine-free, but their effects on the body are not the same as those of true tea.
Why tea is linked with heart health
Tea leaves are rich in natural plant compounds called flavonoids. In green tea, the best-known flavonoids are catechins. In black tea, many catechins are converted into compounds called theaflavins and thearubigins. These substances act as antioxidants in the laboratory, and scientists are studying how they may influence blood vessels, blood pressure and cholesterol.
Large population studies have found that people who drink tea regularly tend to have a lower risk of heart disease and stroke than people who rarely drink it. Smaller clinical trials suggest tea may have modest effects on blood pressure and blood vessel function. It is important to understand, though, that population studies show an association, not proof that tea itself causes the benefit. Tea drinkers may also differ in diet, activity and other habits.
Keeping expectations realistic
Tea is not a medicine, and it cannot undo the effects of smoking, an unhealthy diet or lack of exercise. The best way to think of tea is as one small, enjoyable part of a healthy routine. A heart-friendly lifestyle still rests on the basics:
- Eating plenty of vegetables, fruit, whole grains and legumes
- Staying physically active most days of the week
- Not smoking and limiting alcohol
- Managing stress and getting enough sleep
- Keeping track of blood pressure and cholesterol with your doctor
Simple ways to start
If you would like to add tea to your day, start with plain brewed tea rather than sweetened bottled drinks. Try both green and black varieties to find what you enjoy. Pay attention to how caffeine affects you, especially later in the day, and go easy on added sugar.
The bottom line
Tea is a low-calorie, flavorful drink that contains natural compounds researchers continue to study for heart health. Enjoyed plain or lightly flavored, it can be a pleasant replacement for sugary drinks. If you have a heart condition, high blood pressure or take regular medication, talk with your doctor before making any big changes to your diet or drinking habits.
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