If people with gastric disorders chew gums, excessive gastric acid is produced and this can restart or worsen digestive trouble. If you chew gums before meals, symptoms such as nausea and dizziness appear, and gastritis or stomach ulcer may be developed.
You may also acquire a habit of gritting your teeth in sleep if you chew gums too long.
When young people chew gums too long, their facial muscles and structure is affected thus produces a bad effect on their facial shape.
So it is not good to chew gums too long.
The time of chewing gums should be limited to less than 15 minutes.