Whether it comes as coffee, tea, soda, or a huge can of Monster, most Americans get their caffeine fix in the morning: The Food and Drug Administration estimates that four of every five of us are jolting ourselves awake with caffeine every day. Thankfully, we're also almost all staying under the level at which it becomes acutely worrisome. (The Mayo Clinic puts that number at 400 milligrams per day, or the equivalent of four cups of coffee or 10 cans of soda.) And there are lots of reasons to think caffeine is actually pretty healthy—even beyond the burst of energy that improves people's lives in obvious ways.
But even if you're not using a gallon of cold brew to get through the day, there could be reasons to consider cutting back.
While some studies in the past have linked coffee to conditions like heart disease, they were flawed—most participants in those studies also smoked. As recently as last spring, Frank Chu, chair of the Department of Nutrition at the Harvard T.H. Chan School of Public Health noted that coffee is linked to a number of positive effects: a lower likelihood of type 2 diabetes, liver cancer, Parkinson’s disease, and, yes, heart disease.
Of course, this assumes that your coffee consumption is moderate; Chu says that’s between two and five cups a day for most people. In his new book, Michael Pollan points out that excess consumption—something like eight cups a day—is linked to anxiety and even higher rates of suicide.
If drinking multiple cups of coffee has you running to the bathroom frequently, that’s something else to watch: Peeing more can mean you’re losing nutrients like calcium. But this doesn't have to be a huge problem: You could balance that out by eating leafy greens or even a handful of nuts.
Not everyone loves black coffee. And if you're adding a big glug of cream and a couple spoonfuls of sugar, you've got to account for that too. Caffeinated sodas can be an option for people who don’t enjoy coffee, but those have obvious problems. One can of Coca-Cola contains 39 grams of sugar, which is over 80% of the recommended daily intake.
While sugar in limited amounts is just fine, we also know that excessive added sugar wreaks havoc on the body, contributing to higher risks of obesity and type 2 diabetes. A good guideline is what the American Heart Association recommends: six teaspoons of added sugar a day for women, and nine for men. That can of Coke has 10 teaspoons. A Starbucks Frappuccino might have even more.
It's useful to understand what's actually happening inside your body: Caffeine works by blocking the molecule adenosine, which makes you feel sleepy. Pollan has a clear, concise explanation of what’s going on:
In a sense, every bit of caffeine you put into your body is just borrowed energy. It’s no wonder, then, that regular coffee drinkers might have a crashing feeling in the afternoon, sometimes requiring another cup to get to the end of the work day—and that's when problems can start.
Good sleep is just as important to good health as diet and exercise. Caffeine, naturally, can get in the way of that. The quarter-life of caffeine is 12 hours. If you drink a cup of tea or coffee at noon, or have a soda with your lunch, there’s still caffeine circulating in your brain when you hit the sack. It's obviously even worse closer to bed.
And this can become a vicious cycle: Poor sleep means more caffeine…which only makes your sleep even worse. As Pollan puts it, “[caffeine] is not only a leading cause of our sleep deprivation; it is also the principal tool we rely on to remedy the problem.”
So if you're having trouble sleeping, think hard about your caffeine habits. Try tracking your consumption or setting a firm time after which you only drink decaf. This might mean some rough afternoons, but quality sleep will always mean more energy in the end.
