During the processing of black tea, a chemical reaction centered on the oxidation of tea polyphenols occurred. The chemical composition of fresh leaves changed greatly, and tea polyphenols decreased by more than 90%, resulting in new components such as theaflavins and thearubigins.

The American Medical Association published a survey of 497 men and 540 women for more than 10 years, pointing out that people who drink black tea have strong bones, and polyphenols in black tea have the activity of inhibiting substances that destroy bone cells. The contents of polyphenols in various foods are as follows: black tea-17.4, green tea-12.0, red wine -9.6 and fresh orange juice.

The osaka city university experiment in Japan pointed out that after drinking black tea 1 hour, the blood flow velocity of the heart increased, which confirmed that black tea had a strong role in preventing and treating myocardial infarction.

American magazines report that black tea has stronger anti-aging effect than garlic, broccoli and carrots.

Health care: Black tea can help digestion, stimulate appetite, induce diuresis, eliminate edema and enhance myocardial function.

Disease prevention: black tea has strong antibacterial ability. Gargling with black tea can prevent colds caused by viral diseases, prevent tooth decay and food poisoning, and reduce blood sugar and hypertension.