David Letterman told Esquire in an interview, "If it wasn't for coffee, I'd have no discernible personality at all". I dare say that this is a belief held by millions of people across the globe as they exist daily with their caffeine dependencies. On the popularity scale, coffee holds the title for the world's most popular beverage with a grand total of 400 billion cups consumed each year. That could potentially be a large number of caffeine dependencies.

Is David Letterman really serious when he says that his personality is a derivative of caffeine? Studies show that low doses of caffeine (up to 200 mg) alone can create positive mood effects such as increased well-being, happiness, energetic arousal, alertness and sociability. That means that we would all have great personalities if we stuck to two cups or less of coffee a day. But many coffee drinkers would have to confess that they typically consume two cups or more a day and studies show that higher doses of caffeine, (200 mg or greater) may produce negative impacts including increased anxiety, nervousness, sleeplessness and upset stomach. Remember also that the affects of caffeine can also vary from person to person depending on their body weight, sensitivity, and any tolerance a person has built up toward caffeine..

Caffeine doesn't only hide in coffee. Although 75% of caffeine intake does come from coffee, it can also be derived from other sources as well. This stimulant that we call caffeine is found naturally in coffee beans, tea leaves, and chocolate but is also a popular added ingredient in carbonated beverages and some over-the-counter medications. Surprisingly enough, compared to an 8 ounce cup of coffee that has on average 100 mg of caffeine, a carbonated beverage such as Mountain Dew contains a whopping 55 mg of caffeine. So, you see sources of too much caffeine are not limited to only coffee alone.

With caffeine presenting itself in so many different foods and medications, it's difficult to say that we will just avoid it altogether. So the important question would be, "How much is too much". The American Heart Association states that one to two cups of fresh steaming coffee a day does not seem to be harmful for most people. This would mean 200 mg or less of caffeine intake. It's significant to note that, although caffeine receives a lot of bad press, those that consume moderate amounts, as suggested, can receive certain health benefits as well. These health benefits come from antioxidants and other substances which help regulate blood sugar, prevent gallstones and reduce the risk of Parkinson's disease.

If you are passionate about your coffee and feel that you can't live with only two cups of java a day, it is vital that you make yourself aware of the risks that are associated with increased caffeine intake. Studies that I have looked into explain that an increased level of caffeine can speed bone loss, increase heart risk and might reduce birth weight if too much caffeine is consumed during pregnancy. Women who are pregnant should drink no more than two cups of caffeinate coffee per day and postmenopausal women should also stick to these limits..

The studies on the risks (and benefits) of caffeine intake are ongoing, but quite simply put, the buzz on caffeine is that it makes you feel alert and pumps adrenaline to give you energy. Grab yourself a cappuccino and voila, you now have the caffeine buzz.