Coffee has been long viewed as a vice. We often use "coffee" and "caffeine" interchangeably. After all, a cup of coffee has about 95 mg of caffeine. One 21 fl oz cup of cola, which is about a medium at a fast food joint, has 39 mg of caffeine. A serving an AMP Energy Drink has 74 mg of caffeine. So, coffee is definitely one of the most caffeinated drinks, but it's not so simple.
Caffeine is a drug and, therefore, coffee has been considered a vice. But research has shown that it should also be taken seriously as something that's actually healthy for you.
Studies have linked caffeine to high blood pressure. Most of those studies, however, did not look at coffee. High blood pressure increases the risk for cardiovascular disease. Yet, the following studies show that coffee lowers the risk of developing cardiovascular disease.
A study published in February 2014 in the journal Circulation found that people who consumed one 3 to 5 oz cup of coffee a day were at a lower risk for cardiovascular disease than those who drank no coffee. Participants who drank 5 or more cups of coffee a day had the same risk of developing cardiovascular disease as people who did not drink any coffee. To come to this conclusion, the researchers conducted a meta-analysis and systematic review of 36 studies that involved over 1,270,000 participants.
Another meta-analysis of 11 studies found that drinking 2 to 6 cups of coffee a day was associated with a lower risk of cardiovascular disease. This study had a larger focus on stroke and involved over 480,00 participants.
There was one study that found that consuming coffee increased the risk of developing lung cancer, but that was only among people who smoke. The authors stress that the results of that study should be viewed with caution because smoking is a huge risk factor.
One meta-analysis found a lowered risk of liver cancer linked to increased coffee consumption. The data, published in 2007, found that increasing coffee consumption by 2 cups a day led to more than 40 percent lower relative risk of liver cancer.
That said, too much of any substance is toxic to the body. That even includes water.
Other studies found coffee consumption was not associated with negative outcomes in breast cancer or prostate cancer.
Coffee might reduce the risk of developing diabetes, but people who already have diabetes should be cautious when drinking coffee. Researchers have found that caffeine increases glucose and insulin levels short term. Also, adding sweetener actually increases the risk of developing diabetes.