Knowing the nutritional value of foods can help people make the right dietary choices. In the case of tea, the overall nutritional value of tea is determined by the amount of vitamins, nutrients and minerals that are contained in it. Different tea varieties have different nutritional content, mainly due to the different methods used to process the tea leaves. The tea that has been the least processed retains the higher number of antioxidants and is therefore the more nutritious one.
Of the four main tea types, green and white teas are the least processed ones, while black and oolong teas are highly processed. Green tea is processed by drying the tea leaves in hot air and then steaming them, and white tea usually undergoes only steaming. Black tea is crushed, air-dried and fermented, and, with oolong tea, the leaves only undergo partial fermentation. This processing affects not just the nutritional value of tea, but also its taste, with black and oolong teas being full-flavored ones, and white and green teas having a more delicate, flowery flavor.
In the case of the green and white varieties, the nutritional value of tea is high. Drinking green tea seems to have a positive, healing effect on people with diabetes and those undergoing chemotherapy. Green tea has also been found to be effective in helping clear acne, and in reducing high blood pressure and cholesterol. The antioxidants present in green tea are known to boost the immune system, and have been found to be effective in destroying cancerous cells and in hampering the growth of tumors.
White tea, being the least processed, is richer in polyphenol antioxidants. These have antibiotic properties, and an even stronger cancer-fighting propensity than the green tea antioxidants. Another benefit of white tea is that it contains fluorides that prevent the growth of dental plaque-causing bacteria.
While the nutritional value of tea is comparatively lower in black and oolong teas, many dietitians would recommend them in place of soft drinks. The calories in tea are negligible, and so drinking tea may be healthier, particularly for people who are trying to lose or control their weight. Also, the nutritional value of tea increases when it is taken with milk, and can provide the drinker with much needed minerals and vitamins. The main vitamins in tea are vitamins B, C and E, and the minerals in tea include chromium, manganese, selenium and zinc.
