Is coffee good or bad for you?

Many of us love coffee. We like the caffeine buzz, the taste, the flavors, the many ways it can be enjoyed. But is coffee drinking a bad habit?  Or can we sip our coffee without guilt?
A cup of coffee (that's 8 oz.) or one shot of espresso contains about 80-145 mg of caffeine depending on the ground size, brewing method, and brand. One cup of coffee usually has about twice as much caffeine as a diet soda.  Many studies have shown that caffeine provides a temporary boost in mental focus for critical thinking skills.  Caffeine really does help you focus for that big exam at school or the big project at work!  Also, caffeine gives a short boost in athletic performance (think trying to run your fastest ever mile split). Caffeine won't turn you into an endurance athlete, but it can give you a little kick.  Plus, coffee contains natural antioxidants (similar to the cocoa bean, chocolate!) that may be responsible for it's newly discovered anti-cancer effects. Recent studies in 2006 and 2008 by several different research groups showed that moderate coffee drinkers (3-5 cups per day) had lower risk of colon and liver cancer, type 2 diabetes, Parkinson's disease (only for men), dementia, and Alzheimer's disease.  These benefits from coffee also applied to decaf drinkers, so it's likely that the antioxidants, not the caffeine, are responsible. These are all fairly small studies and they need to be repeated and expanded, so don't drop your health insurance to buy more coffee just yet!  Coffee and caffeine consumption do have some drawbacks: it can cause insomnia when you drink it too late in the day, some people get very jittery and can't focus when they drink it, it stains your teeth over time, and caffeine is a natural diuretic (it dehydrates you). Also, the sugary drinks from coffee shops are full of calories, so they are not a "health drink." Think of those giant mocha lattes with whip cream and chocolate syrup on top - definitely not recommended for dieters!  But, overall, raise a cup o' joe to your health, coffee drinkers!  Just follow it up with a glass of water.