Tea is the second most consumed beverage in the world after water. All tea comes from the Camellia sinensis plant, but different ways of harvesting and processing the plant produce different types of tea. After harvesting, black tea leaves go through a process of wilting, bruising, rolling, and oxidation.Oxidation occurs when the leaves remain exposed to the air for a long time. Enzymes break down the chemicals in the leaves, producing their brown coloring and familiar smell. The process for making green tea is similar, but it does not involve oxidation. Oxidation may give black tea nutritional benefits that are not present in green tea. For example, the nutrients in black tea may reduce the risk of several cancers, protect the heart against atherosclerosis, and help maintain healthy blood pressure. In this article, learn more about the benefits of drinking black tea, as well as the nutrients it provides and the possible risks .

Benefits

According to the United States Tea Association, black tea accounted for around 84% of tea consumption in the U.S. in 2018. Black tea may have similar benefits to green tea. However, many studies have looked specifically at black tea, and how the oxidation process may impact health. A key area of interest is black tea as a source of antioxidants. Antioxidants help combat free radicals. Free radicals are unstable molecules in the body that result from both natural processes and environmental pressures. The body can remove free radicals, but if too many build up, they can damage or change cells in the body. These changes can contribute to the development of many diseases and conditions, such as atherosclerosis and some cancers. Antioxidants can help remove free radicals, and tea is one source of antioxidants. In fact, one study notes that phenolic compounds, which have antioxidant effects, constitute up to 30% of the dry weight of green and black tea. The antioxidants in black tea are different from those in green tea, due to the oxidation process. Green tea mainly contains catechins. During oxidation, these convert into thearubigins, theaflavins, and flavonols.

Protecting against atherosclerosis

Atherosclerosis refers to a buildup of plaque in the walls of arteries. This can lead to coronary heart disease, stroke, and chronic kidney disease. Free radicals can contribute to this condition. A 2004 hamster study suggested that consuming black tea or green tea at human equivalent doses might prevent the development of atherosclerosis. More research is necessary in humans to confirm this. One review suggests that drinking three or more cups of tea per day might help protect against coronary heart disease. However, it is important to note that black tea contains caffeine, and drinking more than three cups per day would contribute a significant amount of caffeine to a person’s daily intake. In 2013, researchers found evidence to suggest that people who drank four cups of black tea or more per day had a lower risk of stroke.

Lowering cancer risk

Findings cited by the National Cancer Institute (NCI) suggest that the polyphenols in tea may decrease the risk of tumor growth. In particular, black tea may help reduce the risk of skin, breast, lung, and prostate cancers. More studies are needed, however, to confirm whether or not drinking tea as part of the diet can help reduce the risk.

Reducing blood pressure

The findings of a 2015 study suggested that black tea may reduce diastolic and systolic blood pressure. Consuming black tea also appeared to cancel out the impact of a high fat meal on blood pressure. This benefit remained despite the caffeine content of the tea. However, this was a small study with only 19 participants, so larger studies are necessary to confirm these results.