What the Chinese have known for centuries about the health benefits of drinking tea, modern Western medicine is only beginning to understand. Many research studies have been conducted over the last few years on oolong, black, and green teas. The findings have shed new light on what substances in these teas foster good health.
Oolong tea is a type of tea that is made by processing tea leaves by wilting in the hot sun, oxidation, and physical manipulation of the dried leaves. The oxidation level can vary greatly, ranging from 8 to 85 percent. The leaves also undergo a small amount of fermentation during processing. This lends the tea a flavor somewhat like black tea but more closely matching green tea. There are a number of different types of this tea that are distinguished by what particular cultivar they are made from. Although less known than the black and green variety, oolong has a number of different positive health effects that has increased its popularity recently. In fact, several scientific studies have found health benefits in the area of heart disease.
A 2010 population study found that drinking oolong was associated with a reduced mortality risk from cardiovascular disease. The study subjects were almost 80,000 adults ranging in age from 40 to 79 years of age. They were free of heart disease, stroke, and cancer at the beginning of the study. Those drinking oolong regularly had reduced risks of developing heart disease compared to non-drinkers. It has been speculated that these effects are due to oolong’s ability to lower cholesterol.
This tea has seen centuries of traditional use in Asia. The many health benefits are being studied extensively. Its medicinal abilities seem to stem mainly from the high flavonoid content. These compounds are strong antioxidants. The leaves are also high in substances called catechins — compounds that halt oxidative cell damage. Studies have shown links between green tea consumption and lowered risk of developing some cancers, like those of the skin, lung, breast, bladder, and colon.
Other health benefits include a reduced risk of developing heart disease. The antioxidants appear to lower level of bad (LDL) cholesterol, while increasing levels of good (HDL) cholesterol. The tea also improves artery function. One Chinese study found up to a 65 percent reduction in hypertension among drinkers of the tea, compared to non-drinkers.
Tea that is black has undergone a more intensive oxidation process that the other types. It has a stronger flavor but comes from the same plant. Considered it is more oxidized, it is somewhat surprising that it has many of the same health benefits of the other teas.
A study conducted by the Netherlands National Institute of Public Health and the Environment showed that regular consumption resulted in a lowered risk of having a stroke. They examined different foods and beverages containing high amounts of flavonoids. Many of the flavonoids they examined came from fruits and vegetables, but 70 percent were derived from black tea. The research followed over 500 men for a 15 year time span. The conclusion of the researchers was that the flavonoids lowered the amount of bad LDL cholesterol in those drinking such teas. Additionally, they found that men drinking over four cups daily had a significantly decreased chance of having a stroke over men drinking less per day.
Taken together, these three teas offer people a variety of tasty beverages that can also support their health. A wide range of flavorful additives are also available to suit the taste of virtually any tea drinker.