A new study by researchers at Louisiana State University, “Tart Cherry Juice Increases Sleep Time in Older Adults with Insomnia,” presented April 28, 2014 at the Experimental Biology 2014 meeting found drinking Montmorency tart cherry juice twice a day for two weeks helped increase sleep time by almost 90 minutes among older adults with insomnia.
Insomnia effects 23 to 34 percent of the population ages 65 and older and is linked to a higher prevalence of chronic pain, high blood pressure, type 2 diabetes and a decline of cognitive function or dementia.
People with insomnia turn to sleeping pills; but sedatives increases the risk of falls for the elderly, so co-author Frank L. Greenway, MD, director of the outpatient research clinic at the Pennington Biomedical Research Center at Louisiana State University believes it was important to find more natural sleep-aids.
"Sleeping pills may be an option for younger insomniacs, but for older people these medications quadruple the risk of falling, which can lead to broken hips and, often, earlier death," Greenway said.
In the randomized crossover clinical trial, seven older adults (average age 68) with insomnia consumed 8 ounces of tart cherry juice twice daily for two weeks, followed by a two-week washout period, then a two-week period when another beverage was consumed (placebo).
The researchers studied the subjects sleep with overnight polysomnography, which monitored the duration and efficiency of their sleep. Blood work was taken and the subjects were later questioned about their sleep, fatigue, depression and anxiety.
The finding showed that those who drank the Montmorency tart cherry juice in the morning and at night were able to sleep more than an hour longer each night (averaging 84 minutes) compared to the placebo, and they had better quality sleep.
Though previous studies found Montmorency tart cherries are a natural source of melatonin, (a hormone that helps regulate the sleep-wake cycle), Greenway and colleagues wanted to understand if the benefits were due to the melatonin or another component in Montmorency tart cherries.
They found it was the red pigments in tart cherry juice called proanthocyanidins that increased the availability of tryptophan, an essential amino acid and a precursor to serotonin that helps with sleep. The juice was shown in cells to inhibit an enzyme (indoleamine 2,3 dioxygenase) that degrades tryptophan.
Co-authors Jack Losso and John Finley, professors in the School of Nutrition and Food Sciences at Louisiana State University Agricultural Center say that tryptophan degradation leads to inflammation and is known indicator of insomnia.
"Even though the amount of tryptophan in tart cherry juice is smaller than normal dose given to aid sleep, the compounds in tart cherries could prevent the tryptophan from breaking down so it's able to work in the body more effectively. These compounds may help to improve tryptophan bioavailability for serotonin synthesis, which could have a positive effect on sleep. Increasing serotonin also helps improve mood and decrease inflammation."
Greenway and his colleagues conclude drinking a glass of tart cherry juice in the morning and the evening is a better and a safer way to treat insomnia