Who Should Avoid Drinking Tea
Who Should Avoid Drinking Tea
Drinking tea is not beneficial for everyone, and whether one can drink tea or how much to drink should be based on individual constitution. Improper tea consumption may harm the body. The following people should limit or avoid drinking tea.
Pregnant women and nursing mothers. Caffeine and theobromine in tea can accelerate heart rate and increase urine output in pregnant women, worsening the burden on the heart and kidneys, potentially triggering pregnancy-induced toxemia. Caffeine may adversely affect fetal development. According to research by Japanese scientists, if a pregnant woman drinks five cups of strong tea daily, it may result in low birth weight for the newborn. Tea polyphenols interfere with milk secretion, and pregnant and nursing women are prone to iron-deficiency anemia, requiring increased dietary iron intake. However, tea significantly inhibits the absorption of non-heme iron from food.
Patients with ulcers. In healthy individuals, phosphodiesterase in the stomach suppresses gastric acid secretion, but theobromine in tea inhibits phosphodiesterase activity. When phosphodiesterase activity is suppressed, gastric wall cells secrete excessive gastric acid, which is detrimental to those suffering from gastric ulcers, duodenal ulcers, or hyperacidity, as increased gastric acid impairs ulcer healing, worsens symptoms, and causes pain. Therefore, ulcer patients should limit or avoid tea.
Patients with severe hypertension, heart disease, or arteriosclerosis. Active substances in tea such as alkaloids, caffeine, and theobromine have stimulating effects on the central nervous system, accelerating cortical excitement, increasing heart rate, and constricting cerebral blood vessels. This exacerbates conditions in patients with tachycardia or cerebral arteriosclerosis, promoting cerebral thrombosis and heart disease. People with these conditions should avoid excessive tea consumption, especially strong tea.
Insomnia patients. Experts have measured that a cup of strong tea contains about 100 mg of caffeine, while the therapeutic dose for adults in medicine does not exceed 100–300 mg. Thus, a cup of strong tea excites the central nervous system and brain, increasing heart rate and blood flow. Drinking a cup of strong tea before bedtime can cause prolonged wakefulness. Insomnia patients should absolutely avoid tea.
Fever patients. Theobromine in tea raises body temperature; drinking strong tea during fever can intensify the condition. The diuretic effect of theobromine can also render antipyretic medications ineffective or greatly reduce their efficacy. Therefore, fever patients should drink plenty of plain water and avoid strong tea.
Anemic patients. Recent comparative studies show that two groups of anemic patients took the same amount of ferric chloride solution: iron absorption was 21.7% in the group drinking water, but only 6.2% in the tea-drinking group; in a ferrous sulfate plus vitamin C trial, iron absorption was 30.9% in the water group versus 11.2% in the tea group; in a bread test, iron absorption was 10.4% in the water group but 33% in the tea group. Clearly, anemic patients should avoid or limit tea consumption.