According to modern scientific analysis, tea contains many elements essential to human physiology, as introduced below:

1. Caffeine (Theine)

Caffeine is a type of alkaloid substance. In each cup of tea containing about two qian (approx. 10 grams) of tea leaves, there is about 4% caffeine. Caffeine is a stimulant for the central nervous system, promoting the activity of the cerebral cortex and enhancing blood circulation. Therefore, tea can refresh the mind and relieve drowsiness. When feeling tired or sluggish, drinking one or two cups of strong tea can clear the mind and eliminate fatigue.

Another effect of caffeine is that it stimulates the kidneys, promoting urination and accelerating the excretion of waste from the body, thus removing toxins. Consequently, regular tea drinkers are less prone to kidney diseases and kidney stones.

2. Tannic Acid

Tannic acid is a common substance in plants. In most tea leaves, the content of tannic acid is about 20%. The astringent taste of strong tea is due to its higher tannic acid content. It has astringent and hemostatic effects, neutralizes alkaline drugs, and dissolves fats, helping digestion, strengthening the spleen, improving appetite, killing bacteria, detoxifying, and treating diarrhea, dysentery, and bleeding such as vomiting blood or coughing up blood.

Tannic acid readily dissolves in alcohol, so drinking strong tea can alleviate alcohol intoxication. It can also help counteract poisoning from nicotine or morphine. Additionally, drinking tea can help protect the body from damage caused by radioactive strontium-90.

3. Vitamins

Tea contains various vitamins such as A, B, C, D, and P, all of which are important for human health. Vitamin C strengthens blood vessel elasticity, enhances resistance to pathogens, and slows skin aging. Vitamin D supports bone development. Vitamins A, B, and P are essential for normal blood maintenance. Drinking two to three cups of tea daily can provide an adequate intake of these vitamins.

4. Aromatic Oils

Tea contains aromatic oils that stimulate the brain, heart, and blood circulation, promoting metabolism and enhancing the body's oxygen absorption. Therefore, drinking strong tea not only clears the mind but also makes breathing feel more comfortable.

Aromatic oils also help eliminate bad breath. Rinsing the mouth with tea can remove fishy and greasy odors.

5. Catechin

Catechin enhances the elasticity and resilience of blood vessels, helping to prevent arteriosclerosis. It also improves the body's ability to adapt to low-pressure environments, preventing discomfort caused by insufficient oxygen at high altitudes.

6. Tea Pigment (Chlorophyll)

Each cup of tea contains about 6% tea pigment, though this amount decreases in fermented teas such as oolong or black tea. Tea pigment helps purify the blood and prevent skin aging, benefiting beauty care for women and those with anemia. For patients with tuberculosis, regular tea consumption can enhance treatment effectiveness.