Study Finds Sleep Aid In Wine Grapes

While melatonin exists in fruit skin, scientists are trying to find it in the final fermented product.

Widely used red wine grapes show possibility as a mild sleep aid, according to a new finding.
The finding, if proven, could open up a marketing opportunity for vintners. The Sacramento region has an expanding winemaking industry.

Researchers in Italy found that popular red wine grapes contain the sleep hormone melatonin. The alcohol in wine, long known to have a sedative effect, might be enhanced by melatonin in grapes.

Their results, published recently in the Journal of the Science of Food and Agriculture, also show that some varieties of wine grapes have much more melatonin than their cousins (for example, cabernet sauvignon has 75 times more melatonin than cabernet franc).

Wine grapes are a combined $152 million business in Sacramento, Yolo, Placer and El Dorado counties, according those areas’ 2004 crop reports. In Lodi, one of the state’s fastest-growing wine regions, the number of wineries has increased to 62 from eight the past 15 years.

Melatonin is a hormone produced by the pineal gland, which is located in the brain and „helps get your body ready for sleep“ said Dr. Michael Kelly, medical director of the south Sacramento Kaiser Permanente Sleep Lab.

The body’s production of melatonin is triggered by the setting sun, so that it eases you into sleep when it becomes dark. When daylight arrives, melatonin production ceases, helping you wake up.

Most animals also use melatonin to help regulate their sleep cycles, but plants don’t sleep. So the question is: Why do grapes make melatonin?

„It’s not that surprising“ that grapes produce it, said Doug Adams, a professor at the UC Davis Department of Viticulture and Enology. Studies have found melatonin in everything from rice to St. John’s wort. There are plenty of plants that make chemicals that change people’s behavior such as coffee beans and opium poppies.

Despite the finding that melatonin is in grapes, there is no proof that it makes it through the fermentation process and into the finished wine. Melatonin may be just like sugar, which disappears during the fermentation process.

If it does make it into the bottle, melatonin will join a long list of beneficial compounds in red wine, including powerful antioxidants that give wine its red color, vitamin C and resveratol, which has shown promise in battling cancer.

Adams said melatonin is made from tryptophan, an essential amino acid, so called because it’s one of the few that humans need but can’t produce on their own. They can obtain essential amino acids by eating foods that contain them. Just a few quick biochemical changes turns tryptophan into melatonin.

Tryptophan already gets a bad rap at Thanksgiving for causing post-meal „turkey nap.“ The tryptophan in turkey is rumored to cause drowsiness, presumably by being the raw material for making melatonin.

While alcohol is a sedative, its effects are short-lived. Kelly advises that „it might help you to get to sleep, but you might end up waking up two hours later.“

Because of the longer lasting sleepiness that it induces, melatonin is often prescribed for patients with sleeping problems, but in doses about 1,000 times higher than what was found in the grapes in the study.

Franco Faoro, one of the study’s authors, has some reservations.

„We think that even if melatonin is present in wine, the effect of the alcohol would be much stronger.“
Faoro’s team is now trying to find out whether wine contains melatonin.

Source: “Sleep aid in wine grapes, study finds,” Charlie Emrich, Sacramento Bee, July 5, 2006

Source: avenuevine.com