Is Your Coffee Buzz Ruining Your Bedtime?

Whether you are a fan of your local cafe or prefer to brew your own Joe, you probably can’t imagine life without a cup of coffee. (Or, if you’re like most people, possibly a few cups!) Unfortunately, the buzz that helps you power through your day may actually be making you more tired. How? If drinking coffee during the day keeps you up at night, then you’ll wake up feeling weary. As a result, you may guzzle even more caffeine, which makes it harder to sleep or do so restfully and, well, you get the point. The “caffeine-disrupted sleep-I’m exhausted” cycle begins! Here, what you need to know about caffeine and sleep.

Caffeine Can Last

As the day goes on, a naturally-occurring molecule called adenosine accumulates in your body while you’re awake. It then inhibits your central nervous system, leaving you feeling tired by the end of the day. But caffeine prevents the production of this chemical so that you’re wide-eyed when it’s time for bed. This is why that afternoon cup can affect the sleep you try to get six hours or more after you consume it. “The half life of caffeine is close to six hours,” explains Michael T. Smith, PhD., director of the Center for Behavior and Health at Johns Hopkins University School of Medicine. “So if you have 200 mg of caffeine at 4 pm you will still have about 100 mg in your system at 10 PM.”  

Tea Isn’t All It’s Cracked Up to Be

This traditionally English drink may seem like a milder version of a rich cup of coffee, but that depends. Although most teas have fewer calories than coffee drinks that are loaded with sugar, milk and other ingredients, some have enough caffeine to keep you wide-eyed. Herbal teas are generally fine, but black teas—like Early Gray and English Breakfast—and even green tea do contain caffeine so take note if you’re sipping these drinks. (Several brands of tea actually list their caffeine levels on the package so take a look.)

Not Everyone is Sensitive to Caffeine

How can your best friend drink lattes late into the afternoon, while just a few sips after lunch keep you up at night? Caffeine’s negative impact on sleep “depends on how much you take, how sensitive you are and how late you typically go to sleep,” says Smith. There is no simple test to see if you are sensitive to caffeine or not, but you can experiment. If you are having trouble falling asleep, eliminate all caffeine in the afternoon. If things get better, then you have your answer. If not, then caffeine might not be your sleep problem. In general, avoid caffeine within 6 hours of sleep and if you’re sensitive to it, avoid decaf, too. (Decaf brews can still contain anywhere between 2 mg and 15 mg of caffeine on average.)

Your Snacks Count, Too

Some of your favorite afternoon snacks may also contain caffeine. This includes chocolate and coffee-flavored yogurt. The good news? In all but the most extreme cases, there is not nearly enough caffeine in chocolate to have a measurable effect on sleep, unless you are highly sensitive. Whew! However, coffee-flavored ice cream and yogurt may have almost as much caffeine as coffee so, if possible, check the container to see if it lists caffeine.

Energy Drinks Have a Downside

Although soda can contain caffeine and may affect your sleep, energy drinks often contain even more—sometimes two or three times as much caffeine as a cup of coffee or cola. As a result, the time of day when you drink these beverages is key. Too late in the day and you’ll be revved up when you’re supposed to be winding down for bedtime.

Michele Bender

Michele Bender is an award-winning freelance writer. She has written for many media outlets, including Family Circle, Glamour, Yahoo! Health, Dr. Oz’s YouBeauty, and The New York Times. She also co-authors/ghost-writes best-selling books for high-profile experts and celebrities. Two of the latest are Curly Girl: The Handbook and The Immune System Recovery Plan.