What are the health benefits of tea?
TEA is the second most consumed bever age in the world, second only to water. All tea, including the four main types (black, white, green and oolong) originates from the same plant, Camellia sinensis. Although all tea has the same origin, the differences occur in the harvesting and processing.1
Green tea starts with freshly picking Camellia sinensis leaves and immediately steaming or pan-frying them to halt oxidation and fermentation, which results in a fresher, lighter flavour. White tea is made in a similar fashion using the newest, youngest buds of the plant. The leaves of black and oolong tea wither and then are rolled and crushed. Oolong tea is partially fermented while black tea is fully fermented.1
Matcha tea, which is recently gaining popularity, is finely ground or milled green tea turned into a powder. Traditional matcha tea powder is then sifted into a bowl with hot water until frothy. When drinking matcha, you consume the whole tea leaf instead of just the infusion, which experts say make matcha nutritionally superior to green tea.
Herbal tea is made from a variety of plants, herbs and spices and in many countries cannot be called “tea” since it does not come from the Camellia sinensis plant. This MNT Knowledge Centre feature is part of a collection of articles on the health benefits of popular foods. It provides a nutritional breakdown of tea, an in-depth look at its possible health benefits, how to incorporate more tea into your diet and any potential health risks of consuming tea.
According to the USDA National Nutrient Database, one cup of black tea (approximately 237 grams) contains 2 calories, 1 gram of carbohydrate, 0 grams of sugar, 0 grams of fibber and 0 grams of protein as well as 26% of daily manganese needs and small amounts of riboflavin, folate, magnesium, potassium and copper. The caffeine contained in a cup of tea can vary according to the length of infusing time and the amount of tea infused.
Overall, tea contains few calories, helps with hydration and is a good source of antioxidants. Catechins, potent antioxidants found primarily in green tea, are known for having beneficial anti-inflammatory and anti-carcinogenic properties. A study published in the Journal of Physiological Anthropology looked at the effects of green tea, white tea and water consumption on stress levels in 18 students. The study suggested that both green and white tea had a lowering effect on stress levels, however, white tea had an even greater effect. Larger studies need to be done to confirm this possible health benefit.
Some studies suggest that tea may be beneficial in reducing the risk of dementia and even enhancing our brain’s cognitive functions, particularly the working memory. A 2006 study published in the Journal of the American Medical Association concluded that green tea consumption is associated with reduced mortality due to all causes, including cardiovascular disease.