A favorite beverage of many athletes, trainers, and nutritionists, juice made from tart or "sour" cherries (the kind you use to make cherry pie) has been shown to reduce inflammation and ease muscles soreness after strenuous workouts. But that's not the only reason you might want to consider drinking the not-quite-KoolAid. According to new research, the fruit can also help improve sleep for people with insomnia.
In the new study, funded by the Cherry Marketing Institute, scientists from Louisiana State University gave half of their volunteers tart cherry juice twice a day—morning and night—for two weeks, while the other half drank a cherry-flavored placebo liquid; then, for another two weeks, the groups switched. When the volunteers were drinking the real cherry juice, they slept about 85 minutes longer per night—a significant improvement for people experiencing chronic sleep problems.
"The mechanism that we discovered was responsible for better sleep is the same mechanism that's responsible for reducing muscle soreness," says lead author Frank Greenway, MD. The juice inhibits an enzyme known as IDO, he explains, which in turn increases tryptophan (an amino acid that promotes sleep) and decreases the presence of prostaglandins (chemicals that contribute to inflammation and pain). Tart cherries have also been shown to contain natural melatonin, another potential sleep promoter.
Don't worry about cherry juice making you groggy, though: Sipping it during the day didn't make any study participants feel tired afterward. "It was interesting how no one complained about that," says Greenway. "It was just that when they eventually did lie down to go to bed, they fell asleep faster and slept better."
Greenway's study was done on adults 65 and older, a population that often suffers from sleep problems. And although he hasn't tested cherry juice's effect on younger insomniacs, he says there's no reason to think it wouldn't work the same way for all age groups.
Bottom line: "Everyone functions better with proper sleep, and if by the same mechanism you can reduce inflammation as well, that's even better," says Greenway, who recommends drinking one to two cups a day for best results. Keep in mind, though, that cherry juice (even the tart stuff) contains about 130 calories per 8-ounce glass—so make sure it fits into your daily nutrition plan, and don't overdo it.