If you’re like most people, you rely on caffeine to get going in the morning, so it’s important to be aware of how it can affect your health. Most people have a perfectly safe amount, but excessive use can be dangerous.
A cup of brewed coffee has about 125 mg of caffeine, instant coffee a little more than half that, and a 12-oz bottle of soda between 30 and 40 mg. Heavy caffeine use is more than 500 to 600 mg per day, and can lead to nervousness, restlessness, irritability, upset stomach and rapid heartbeat.
Caffeine will mitigate tiredness, and can help you wake up or stay awake, but it doesn’t change the amount of sleep you need. That means that trying to substitute coffee for sleep, while it may seem to work at first, can cause harm in the long run. Worse, it can lead to a vicious cycle, in which you use caffeine to stay awake, which interferes with sleep, making you wake up tired, which you try to deal with by turning to caffeine. Studies show that people who are inclined to be night owls anyway find their sleep less affected.
In addition, there are some benefits to caffeine consumption. A long-term study following a group of volunteers has produced data indicating drinking coffee reduces the risk of depression. Coffee and tea, common sources for caffeine, contain polyphenols, a type of antioxidant, which can prevent blood clots. Drinking coffee regularly can help protect you from heart attacks and strokes and prolong your life.