Children should not drink coffee. It has some beneficial effects but the number of bad consequences is long term. Bad effects are due to its caffeine content. It is a strong and fast acting drug. It makes a person more alert and attentive by pushing the body to its limit. Having a cup could extend the hours of work longer. The effectiveness may differ from person to person.
Other sources of caffeine are soft drinks, chocolates, energy drinks, medicines and other foods flavored with coffee and chocolate. Popular mocha and rocky road flavored ice cream obviously contain caffeine. If you gonna prohibit your child from drinking coffee, the above listed food commodities should be prohibited as well.
The adverse effects of caffeine are the following:
1. According to studies, prolonged consumption of caffeine has resulted to hyperactivity and restlessness in children. In hyperactivity a person is abnormally and easily excitable. May show strong emotional reactions and impulsive behavior. While restlessness is an inability to be comfortable, stay still or quiet.
2. Suspected to cause cancer and cardiovascular disorders. It is better to stay away from coffee and other caffeine sources even if there are no enough evidences yet.
3. Accelerate bone loss. Rapidly growing children should gain calcium but caffeine facilitate its excretion. If a child losses calcium more rapidly than what he is gaining, the result is stunted growth.
4. Decrease the appetite for other foods resulting in weight loss and inadequate nutrition.
5. Irritates the stomach lining and force it to produce more acid. It relaxes the muscles of digestive system resulting in a less effective digestion.
I think, even adults should not drink coffee!