As time goes on and new research seems to frequently contradict old research, one sentiment that has remained a constant for thousands of years is that tea is healthy. Somehow before studies of its chemical contributions to the body and before large meta analyses were performed, it was used as a medical drink in China as far back as 300 AD. Many different brews are called tea, but some purists only consider green tea, black tea, white tea, oolong tea and pu-erh tea actual tea. These are all derived from the Camellia sinensis plant, a shrub that is native in China and India. One of the predominant traits of these plants is that they contain unique antioxidants called flavonoids; the most potent one being epigallocatechin gallate, or EGCG. EGCG is thought to help fight against free radicals that contribute to serious diseases such as cancer, heart disease, diabetes and more. 

Green Tea

One of the most common and studied tea, green tea is made with steamed tea leaves and has a high concentration of EGCG. Green tea’s high amount of antioxidants may help fight against the overgrowth of different forms of cancer, clogging of arteries, excessive fat storage, and counter oxidative stress on the brain which reduces the risk of neurological diseases like Alzheimer’s and Parkinson’s disease.

Black Tea

Black tea is made with fermented tea leaves, and has the highest caffeine content of all teas. It is commonly used as a base flavor in flavored teas like chai as well as some instant teas. Black tea is shown to protect lungs from damage caused by exposure to cigarette smoke, and has also been shown to have protective dental properties.

White Tea

White tea is uncured and unfermented, and partially because of this has the most potent anticancer properties compared to more processed teas.

Oolong Tea

Oolong tea has been proven to lower cholesterol levels in animals, so it is very likely to help prevent heart disease in humans. A certain variety of oolong tea, called Wuyi is frequently marketed as a weight loss supplement, but these claims have not yet been proven by science.

Pu-erh Tea

Pu-erh tea is made from fermented and aged leaves. Sometimes also considered a type of black tea, its leaves are pressed into cakes (shown below). Like oolong tea, pu-erh tea has been proven to reduce LDL cholesterol in animals.

Sleepy Time Teas

Sleep teas don’t have any caffeine and are thought to help you go to sleep at night. A common sleep tea is chamomile tea, and it has been studied for its sleep-inducing effect. The calming effects in chamomile are attributed to the antioxidant, apigenin. Some sleep teas include liquid melatonin to help the drinker get to sleep as well. Aside from the ingredients that help the user sleep, the act of drinking tea may help induce sleep as well. Many people think of tea as relaxing, and some people have a nighttime routine that helps the body start to relax.

Conclusion

Regardless of the type of tea, it has been thought to be very beneficial for one’s health for thousands of years, and research is only proving those theories right. As society progresses, theories are continuously tested by science, and some stand while others fall. It seems that drinking tea is something that should be a concrete habit solidified in every person's life to promote longevity.