CAFFEINE: FRIEND OR FOE
Caffeine jump-starts your day and puts a bounce in your step. It can help you focus, improve your mood and maybe even help you live longer. But how much is too much?
Caffeine, a natural stimulant, can be found in a variety of foods, such as coffee beans, tea leaves, cacao beans, guarana berries and yerba maté leaves. It also can be synthetically created and added to beverages such as soda and energy drinks.
Research shows that about 90% of U.S. adults consume some form of caffeine every day. One of the most popular ways people consume it is through coffee. Because of that, most caffeine research centers around this drink, said Dr. Greg Marcus, associate chief of cardiology for research and a professor of medicine at the University of California, San Francisco. "The literature on the whole shows that coffee consumption is generally not a detriment to health," he said.
Studies have found caffeine can do both good and harm. People who regularly drink coffee may be less likely to develop chronic illnesses, such as cardiovascular disease, diabetes, Parkinson's disease and some cancers. A few studies suggest they are less likely to die from heart disease and other illnesses.
According to the Food and Drug Administration, as much as 400 milligrams of caffeine a day – equal to four or five cups of coffee – is considered safe for healthy adults. An 8-ounce cup of green or black tea has 30-50 mg of caffeine. Energy drinks may contain 40-250 mg for every 8 ounces, and a 12-ounce can of caffeinated soda contains 30-40 mg.
In moderate doses – up to two 8-ounce cups of coffee – caffeine can make people less tired and more alert. Some studies suggest it can reduce appetite and lower the risk for depression. But high doses – 12 cups or more – can make people feel anxious, raise blood pressure and lead to heart palpitations and trouble sleeping. For people who consume caffeine regularly, stopping consumption abruptly can lead to symptoms of withdrawal, such as headaches, fatigue and depressed mood.
Determining how much is too much can be tough. A moderate amount of caffeine for one person may feel like a high dose for someone else. That's because some people metabolize caffeine faster than others, Marcus said. Factors such as how much someone weighs and what medications they take also can play a role. The bottom line is, caffeine affects everyone differently.
Read more on our Maud's Coffee & Tea blog here. 
