5 Science-Backed Health Benefits of Drinking Tea

Drinking two to three cups of tea daily is associated with a modest reduction in mortality, according to large-scale epidemiological research published in the Annals of Internal Medicine. As the world’s most popular beverage after water, consumed by nearly two-thirds of the global population, tea has been the subject of decades of scientific inquiry into its potential health benefits, ranging from cardiovascular support to improved metabolic and brain health.

Longevity and Mortality Findings in Large-Scale Studies

One of the most consistent findings in tea research is that regular consumers tend to live slightly longer than non-consumers. In a 2023 study published in the Annals of Internal Medicine, researchers tracked roughly half a million adults in the United Kingdom between the ages of 40 and 69 for more than a decade, evaluating their diets, lifestyle habits, and medical conditions. About 90 percent of the tea drinkers in the cohort consumed black tea, while roughly 7 percent preferred green tea.

The analysis revealed that individuals who drank two to three cups of tea daily experienced a 13 percent reduction in mortality compared to those who rarely or never drank tea. These outcomes remained consistent regardless of whether participants also consumed coffee. Similar results have emerged across a rigorous meta-analysis involving approximately 2 million adults across North America, Europe, Asia, and Australia. Researchers emphasize that these studies demonstrate correlation rather than direct causation, as other lifestyle factors may contribute to the observed longevity.

Cardiovascular and Vascular Health Benefits

Beyond longevity, scientific trials indicate that tea consumption protects and relaxes blood vessels. A study published in the journal Circulation investigated the effects of black tea on vascular health by assigning 66 adults with coronary artery disease to drink roughly three cups of black tea daily for four weeks, alongside a separate phase where participants drank only water. The researchers found that black tea improved vascular function, an effect driven by increased levels of polyphenols in the participants’ blood. Furthermore, multiple clinical trials show that daily consumption of both black and green tea can slightly lower blood pressure over periods of weeks or months.

Polyphenols, Plant Compounds, and Tea Varieties

The biological mechanisms behind these health benefits stem from the rich chemical profile of the tea plant. Jenifer Bowman, a cardiac dietitian at UCHealth in Fort Collins, Colorado, notes that a typical cup of brewed tea contains numerous antioxidants, polyphenols, and other beneficial plant compounds comparable to those found in coffee, cocoa, fruits, and vegetables. Although green, black, white, and oolong teas display distinct appearances and flavors, all four varieties derive from the same plant species: Camellia sinensis. The differences in flavor and appearance depend on how the leaves are aged and processed.

Herbal teas, including chamomile, mint, hibiscus, and ginger, are produced by brewing herbs, spices, and flowers rather than Camellia sinensis leaves. While herbal options contain varying levels of polyphenols and typically lack caffeine, much of the clinical research on disease prevention has centered on black and green tea as the most widely consumed varieties worldwide. Researchers describe tea as Nature’s gift for promoting human health in analyses published in the journal Life Sciences, citing its capacity to protect blood vessels, lower inflammation, aid relaxation, and potentially support the gut microbiome.