1.Tea Knowledge: Drinking tea immediately after a meal may cause anemia; drinking tea right after eating introduces a large amount of water into the stomach, which is digesting food, diluting the digestive juices secreted by the stomach and thus affecting digestion. While it may clean the mouth and aid digestion, drinking tea immediately after a meal is detrimental to health and poses a hidden risk for future anemia.

2. Tea should not be brewed too strong; drinking tea on an empty stomach can easily inhibit gastric acid secretion and hinder digestion; regularly drinking green tea can prevent cancer. However, Japanese research found that drinking at least 5 cups a day is necessary to see effects; diabetics should drink white tea, while office workers should drink more green tea. French research also found that women who drink more than 3 cups of tea a day reduce their risk of thrombosis by 32%; it is best to drink red tea in the evening. Because green tea is unfermented and contains higher levels of tea polyphenols, it is more stimulating; red tea is fully fermented and less stimulating.

3. People who should avoid drinking tea: Those suffering from constipation.

Because the polyphenols in tea have a certain constricting effect on the gastrointestinal mucosa, tea consumption can worsen constipation in patients.

Those with iron-deficiency anemia.

Because the tannic acid in tea causes iron from food to form precipitates that are not absorbed by the body, worsening anemia.

Those with calcium deficiency or fractures.

Because the alkaloids in tea inhibit the duodenum's absorption of calcium, and can also lead to calcium deficiency and osteoporosis, making fractures difficult to heal.

Those with ulcers.

Because the theophylline in tea reduces the activity of phosphodiesterase, causing stomach wall cells to secrete large amounts of gastric acid. Excessive gastric acid inevitably affects the healing of ulcers and counteracts the efficacy of certain antacid medications.

Those with urinary system stones.

Since tea contains relatively high levels of oxalic acid, drinking tea will aggravate the development of stones.

Those with neurasthenia.

Because the caffeine in tea has a clear stimulating effect on the cerebral cortex, so drinking tea can keep the brain in a state of extreme excitement without rest for such patients.

People with fever.

Because the theophylline contained in tea can raise body temperature, greatly reducing or negating the fever-reducing effect of medications. Therefore, it is not advisable to drink tea when having a fever.