Excessive consumption of bananas will lead to imbalance of trace elements. Bananas are delicious fruits, so some people (people with acute and chronic nephritis and renal insufficiency) eat bananas in large quantities at one time. Bananas contain more elements such as magnesium and potassium. Although these mineral elements are necessary for human health, if they are ingested too much at one time in a short period of time, the contents of magnesium and potassium in the blood will increase sharply, resulting in the imbalance of potassium, sodium, calcium, magnesium and other elements in the body, which is harmful to health. In addition, eating more bananas will also cause gastrointestinal dysfunction and excessive mood swings due to the greatly reduced gastric acid secretion. Immature bananas are easy to cause constipation. As we all know, when bananas are immature, the skin is turquoise, and the skin is peeled off and cannot be swallowed. Bananas are tropical and subtropical fruits. In order to facilitate storage and transportation, when picking bananas, you can't wait until the skin is green. The astringency of raw bananas comes from the large amount of tannic acid contained in bananas. Tannic acid has a very strong astringent effect, which can form dry and hard feces, thus causing constipation. The most typical thing is that after eating bananas, the elderly and children can't help but defecate, but they can have obvious constipation.