After water, tea is the most-consumed drink in the world, enjoyed by diverse cultures across the world since ancient times. Different teas are often heralded as having health benefits, several of which have now been scientifically validated.

Oolong is a traditional Chinese tea that contains an amino acid that reduces anxiety and increases alertness and attention. Scientists have discovered that this amino acid can help prevent Parkinson’s and Alzheimer's diseases.

Black tea is made from the dried and fermented leaves of the Camellia sinensis plant. Black tea drinkers will benefit from the tea’s flavonoids, which combat inflammation and support healthy immune function. Of the tea types, black has the most caffeine, which may be of concern to some people.

In China, green tea leaves are roasted, and in Japan, green tea leaves are typically steamed. Green tea is very high in compounds that can lower bad cholesterol and reduce blood clotting. If you want decaf green tea, look for teas that are decaffeinated using a natural water process instead of chemicals. More of the good stuff is retained during the non-chemical process.

White tea is among the least-processed tea types and it does contain some caffeine. It has a high level of antioxidants. It’s also good for your teeth because it contains fluoride and other substances that can strengthen teeth, fight plaque and make them more resistant to acid and sugar.

The leaves of the rooibos plant—native to South Africa— are used to make rooibos tea. This caffeine-free herbal tea is rich in antioxidants. It boosts good cholesterol, lowers bad cholesterol, keeps hair and skin healthy, and provides allergy relief.

Another no-caffeine herbal tea, mint tea contains menthol, which can have gastrointestinal benefits. Menthol can help with upset stomach, constipation, irritable bowel syndrome and motion sickness. Mint tea can also help with headaches.

Chamomile tea, known for its soothing qualities, is made from the dried flowers of a plant native to southern and eastern Europe and western Asia. If you feel stressed out or you're having trouble sleeping, consider a cup of chamomile tea.

Many tea drinkers like the tart flavor of hibiscus tea, which is made from hibiscus flower parts. This herbal tea can lower blood pressure and fat levels. It can also reduce cravings for unhealthy sweets and improve liver health and it may even prevent kidney stones.