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The Health Benefits of Tea

Contributors: Barbara Gordon, RDN, LD

Reviewers: Academy Nutrition Information Services Team

Published: November 02, 2022

Reviewed: December 11, 2023

Woman holding a glass mug, standing in kitchen, smelling and drinking hot tea beverage
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Nearly half of the U.S. population enjoys a tea beverage every day. The most common types of caffeinated teas are black, green and oolong and the popularity of each type varies geographically. In the U.S., black tea consumption far outweighs the other two types of tea. In contrast, in Asia, green tea is the more common variety; in Southern China, oolong tea tops the charts.

Black, green and oolong tea are made from the same plant. The unique flavor profiles for each of these teas are due to differences in how the leaves of the Camellia sinensis plant are processed. Herbal teas, however, are not made from the same plant. These teas are products of the roots, leaves, flowers and other components of a variety of plants. Chamomile and peppermint are two popular herbal teas. Chamomile is made from the plant’s flowers and peppermint tea is produced with the leaves of a mint plant.

Caffeine and Nutrients in Tea

Black, green and oolong tea all contain caffeine. Black tea has more caffeine than green tea. However, the caffeine content also relates to the brewing process. The longer tea steeps, the greater the caffeine content. Caffeinated teas typically have less caffeine than coffee:

  • One 8-ounce cup of coffee contains about 95 milligrams of caffeine.
  • An equal amount of black tea has around 48 milligrams.
  • In a cup of green tea, there are only about 29 milligrams of caffeine.
  • Oolong provides about 38 milligrams of caffeine per cup.
  • Decaffeinated black, green and oolong teas contain very small amounts of caffeine.
  • Many herbal teas are caffeine-free.

Both caffeinated and herbal teas may provide very small amounts of minerals such as potassium, phosphorous, magnesium, sodium, copper and zinc. The actual amount varies depending upon the age and growing conditions of the tea plant. For instance, there are only about 5 milligrams of calcium in one cup of herbal tea, such as chamomile. Tea also is a source of fluoride, but the amount can vary depending on the type and the amount of water used to make it.

Purported Health Benefits of Tea

Natural substances called polyphenols are found in both caffeinated and herbal teas. These substances are antioxidants, compounds that may help reduce the risk of certain chronic diseases.

During processing, some polyphenols in tea are destroyed. Thus, tea powders, decaffeinated teas and bottled tea drinks may not offer the same health benefits. Additionally, research suggests that green teas offer a greater antioxidant punch compared to most other varieties.

Weight Management

The research on drinking tea and weight loss is conflicting. Some studies suggest that the caffeine and catechins, a type of polyphenol, in tea may support weight loss. Decaffeinated green teas did not appear to produce the same results. Other lifestyle factors, such as physical activity, also may have played a role. Also of note, research is lacking to support the wide range of herbal tea products advertised for weight loss, and these can be harmful depending on their ingredients.

Heart Health

Tea drinkers may be helping to keep their hearts healthy. Some research has shown a reduced risk of heart disease in people who drink green tea regularly with some studies showing small decreases in low density lipoproteins (LDL), or “bad” cholesterol, levels. Findings have been mixed in terms of tea’s effect on lowering blood pressure.


Research relating to diabetes is less clear. Researchers are evaluating if spearmint and chamomile herbal teas can play a role in preventing diabetes. More research is needed on the amount and type of tea, especially since some of the results have involved tea in supplement form rather than a beverage.


Although there is a lot of information online about tea as a cancer-fighting beverage, research has not proven that consuming tea helps to reduce the risk of cancer. Some studies suggest tea drinkers have a lower risk for certain types of cancer, but other studies do not support these findings. At this time, it is unknown if tea drinking can reduce your risk of cancer.

Too Much of a Good Thing: Health Risks of Tea

While there are lots of good things about consuming tea, overdoing it can put your health at risk.
One risk is caffeine overload. Large amounts of caffeine may lead to nervousness, restlessness and may disturb your sleep. Some people may experience loose stools and other gastrointestinal issues. Nausea, abdominal pain, heartburn, dizziness and muscle pain are other possible side effects of consuming too much caffeine. Also, tea may interact with certain medications and increase the effects of caffeine in the body. Total daily intake of caffeine from all sources should not exceed 400 milligrams.

A Nice Cup of Tea

Although more research is needed to pin down all of its benefits, tea can be part of a healthy eating pattern. For the most powerful punch, steep your own tea and be mindful of how it is sweetened in order to limit sources of added sugars.

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