Research in Your Cup

Glass of green tea

The Hot, Healthy Benefits of Tea

Long nights, cold days and plenty of indoor time: ’Tis the season to reach for a hot, soothing cup of tea. After water, tea is the most widely-consumed beverage in the world, so it’s fortunate that studies suggest this beverage may protect against cancer, as well as offer other health benefits.

A Mugful of Cancer-Fighters

Much of the research in cancer prevention focuses on green tea, which is especially high in the compound epigallocatechin-3-gallate (EGCG). ECGC is a phytochemical that acts as an antioxidant. Lab studies consistently show that EGCG fights against many types of cancer. In cell and animal studies, it slows cancer growth, inhibits the ability of tumors to spread and leads to cancer cell death without affecting normal cells.

Kaempferol is another phytochemical in tea that has shown cancer-fighting ability in lab studies.

But the evidence in tea’s cancer-preventing ability from population studies is less compelling. Although several studies suggest a link between high green tea consumption and a decreased risk of some cancers, overall findings are inconsistent.

Part of the challenge in studying the effects of tea consumption relate to differences in tea preparation and type. Distinctive types of tea (see below) contain varying phytochemicals, and the strength of brewing the tea plays a role in the amount of phytochemicals. It's worth noting that many of the population studies take place in Asia, where green tea is a common beverage that people start drinking at an early age.

Emerging research may help identify if there are certain populations that may benefit more from tea, based on particular genes, age or dietary habits. A wide body of research also links tea to reducing the risk of cardiovascular disease.

Green Tea, Black Tea, White Tea, Red Tea

All teas start from the same plant, the Camellia sinensis plant. The difference in the type of tea stems from the processing and its oxidation. Oxidization is the process where the tea leaves interact with oxygen. The longer a tea leaf reacts with oxygen, the darker it becomes.

  • Black tea: It is the most oxidized of the types of tea and thus, the darkest. Leaves are crushed, oxidized, then heated, which stops the oxidation process.
  • Oolong Tea: This goes through the same process as black tea, but it is oxidized for about half the time.
  • White tea: The least processed tea, it starts with the buds or young leaves, which are immediately steamed and then dried.
  • Green Tea: Tea leaves do not undergo an oxidation process. The leaves are steamed and then dried.
  • Herbal teas: Herbal teas do not come from the Camellia sinensis plant, so they are not true teas. They are a blend of leaves, roots, seeds or flowers from other plants. Although studies no not link herbal teas with cancer prevention, they still contain plenty of phytochemicals and more importantly, offer a no-calorie hot and tasty beverage.

Sipping Your Way to Health

Whatever type of tea you prefer, enjoy many a mugful because cancer prevention may be only one health benefit.

When it comes to getting to a healthy weight—the always-popular New Year’s resolution—sipping on zero-calorie tea is a great choice. Switching from a high-calorie beverage, like sugary soda, to a barely- or non-sweetened tea can especially help with weight loss. Drinking tea frequently and consistently is generally where the health benefits are seen.

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