Caffeine is a stimulant found in products such as coffee, tea and soft drinks. The drug affects your central nervous system and causes side effects such as feelings of alertness and higher energy, though there appears to be no scientific evidence to show that it damages your brain or causes brain damage.

Caffeine exists naturally in certain plants but also can be created synthetically. When you drink caffeine, your body absorbs it very quickly and it passes to your brain, according to MedlinePlus, a service of the National Institutes of Health. The drug does not accumulate in your body and gets excreted through your urine after several hours. In addition to popular drinks, caffeine often is present in various medications, such as pain relievers, cold medications and diet pills.

Currently there is no evidence to show that caffeine causes or leads to brain damage. In fact, caffeine actually might serve to help protect or even heal your brain. According to a 2010 study published in "The Journal of Alzheimer's Disease," caffeine might protect you from the mental decline associated with medical conditions such as Alzheimer's disease and dementia. The study reported that people who regularly consume moderate amounts of caffeine had an inverse correlation to cognitive decline, meaning they were less likely to experience such declines as opposed to those who were not regular caffeine consumers.

While caffeine isn't associated with brain damage, there are other potential side effects of which you should be aware. MayoClinic.com reports that ingesting too much caffeine is not good for you, as it can lead to symptoms that include insomnia, nervousness, irritability, increased heartbeat and muscle tremors. These symptoms might appear if you drink more than 500 to 600 mg of caffeine per day, the equivalent of drinking between about four and eight cups of coffee.

The beneficial and negative effects you experience with caffeine do not exist in a vacuum, and you always should view your caffeine consumption as a small part of your overall health and well-being. The American Medical Association Council on Scientific Affairs says that while moderate use of caffeine will likely have no negative effect on your health, you must still engage in an otherwise healthy lifestyle. For example, though caffeine might protect against some brain conditions, if you drink a lot of high-calorie caffeinated drinks, such as colas, it might lead to weight gain and associated health problems, such as obesity, high blood pressure and diabetes.