Why caffeine is worse than you think for sleep
I am a coffee lover! Truth be told, I cannot get through the morning without at least a cup (of the caffeinated variety!)-and I prefer more.
The health perks of coffee only add fuel to my habit: drinking coffee regularly can help lower cholesterol, and may reduce your risk for heart disease, type 2 diabetes, dementia, Alzheimer's and Parkinson's diseases.
But then I came across this study, which we had Karen Ansel write about in the May/June issue of EatingWell Magazine, that really put a damper on my enthusiasm for coffee. Researchers at the University of Montreal examined how caffeine affected sleep quality in 24 men and women ranging in age from 20 to 60 years. (Find out who gets a bigger buzz from coffee: men or women?)
Here's what they did: participants were deprived of sleep for 25 hours and then given roughly the amount of caffeine in 16 ounces of brewed coffee or four to five 8-ounce cups of tea before they were allowed to get some shuteye. As one would expect, all the participants slept less, and less restfully, than when they completed the same experiment minus the caffeine. They also experienced less slow-wave sleep, the deep sleep that helps you feel refreshed.
No duh, right!? But here's what I found most intriguing: the caffeine appeared to interfere more with the middle-aged subjects' sleep.
There's already a major decrease in slow wave sleep as early as age 40. When we spoke with the lead researcher, Julie Carrier, Ph.D., she recommended that especially as people get older they to try to reduce their caffeine consumption as much as possible.
What about those of us who don't want to give up our coffee or tea? (Granted, I have a ways to go before I turn 40, but I can't imagine foregoing that morning jolt ever.) Carrier's suggestion: minimize caffeine's sleep-stealing effects by drinking it as early in the day as you can.