Tea has the effects of refreshing the mind, promoting digestion, and benefiting health, and is closely related to people's daily lives. However, if tea is brewed too strong, it can harm the body. Especially for the elderly, paying attention to the strength of the tea is particularly important for protecting their health.

Generally speaking, elderly people who frequently drink large amounts of strong tea are prone to many physical discomforts. For example, it can easily cause dilution of gastric juice, leading to improper digestion. A person normally secretes 1.5–2.5 liters of gastric juice per day, which is enough to properly digest the food consumed daily. When a large amount of strong tea is drunk, it dilutes the gastric juice, reduces its concentration, and prevents it from digesting food properly, resulting in indigestion, bloating, abdominal pain, and even duodenal ulcers in some cases.

In addition, tea hinders the body's absorption of iron. Tea leaves contain tannic acid—black tea contains about 5%, and green tea about 10%. When people drink large amounts of strong tea, the combination of tannic acid and iron becomes more active, obstructing and affecting the body's absorption of iron, leading to iron deficiency anemia.

Moreover, drinking strong tea can easily cause constipation. The tannic acid in tea not only binds with iron but also combines with proteins in food to form a lumpy, indigestible substance called tannic acid protein, which leads to constipation. For elderly people who already suffer from constipation, this can make the condition even worse.

Finally, strong tea can cause increased blood pressure and heart failure. The caffeine in strong tea can accelerate the heartbeat, thereby raising blood pressure. At the same time, a large amount of strong tea liquid entering the blood vessels can increase the burden on the heart, causing symptoms such as chest tightness and palpitations, and worsening the degree of heart failure.

Everything in moderation. Drinking weak tea can nourish health, while drinking strong tea harms health. For longevity and a peaceful old age, it is hoped that elderly people will choose weak tea over strong tea.