Tea contains 2%~5% caffeine, and the caffeine content in strong tea is higher. A cup of strong tea contains about 100 mg of caffeine. Excessive caffeine can lead to nervous overexcitation and insomnia. At the same time, it can also cause tachycardia, which is not good for people with tachycardia, premature beats and atrial fibrillation.

Other hazards of strong tea:

1, the effect of strong tea on the stomach

The concentration of caffeine and theophylline in strong tea is too high, which increases the excitability of the central nervous system, which can lead to accelerated gastric peristalsis, excessive secretion of gastric wall cells, increased gastric acid, enhanced stimulation of gastric mucosa and easy to lead to gastric ulcer.

2. Effect of strong tea on nutrient absorption

Strong tea also contains a lot of tannic acid, which can be combined with protein, vitamin B 1 and iron ions in food, so that these nutrients can not be absorbed normally, and it is easy to cause nutritional deficiency in human body, resulting in corresponding situations, such as anemia and constipation.

Extended data:

Precautions for drinking tea:

1, drink tea on an empty stomach

Drinking tea on an empty stomach will cool the spleen and stomach, which is equivalent to "inviting wolves into the room." There has been a saying in China since ancient times that "you don't drink hollow tea".

Step 2 drink hot tea

Too hot tea irritates throat, esophagus and stomach. If you drink too hot tea for a long time, it may cause pathological changes in these organs. According to foreign research, people who often drink tea with a temperature over 62 degrees Celsius are more likely to damage the stomach wall and suffer from stomach problems.

Step 3 drink herbal tea

Warm tea, hot tea can make people think clearly, and their ears are bright; Herbal tea has the side effect of cold coagulation and phlegm accumulation.

References:

People's Network-Beware: Always drink strong tea and be alert to the four pests.

References:

People's Network-Drinking more tea is better than drinking less. Seven taboos that should be paid attention to.