It’s that time of year again – the clocks have gone back and the nights are drawing in. The decrease in daylight hours can lead to increased risk of depression and SAD (Seasonal Affective Disorder), which can affect sleep patterns and make it harder to get your full eight hours of shuteye.

If you have difficulty sleeping, a daily shot of cherry juice can help you to nod off more easily. The tart Montmorency cherries contain a natural source of melatonin, the hormone needed for restful sleep – and studies have shown that other chemical compounds found in Montmorency cherry juice contribute to restful sleep as well.

A 2010 study carried out by the School of Life Sciences at Northumbria University found that Montmorency cherry juice increases levels of melatonin in the body. Volunteers drank 30ml of either Montmorency cherry juice concentrate or a placebo juice twice a day for seven days. Participants wore sensors that monitored their sleep-wake cycles and kept a daily diary on their sleeping patterns. Those who had the cherry juice saw an increase of 25 minutes in their total sleep time and a six per cent increase in sleep quality.

A 2014 study carried out by Louisiana State University in the US found that for older people with insomnia drinking Montmorency tart cherry juice twice a day for two weeks helped increase sleep time by nearly 90 minutes.

As well as the high melatonin content in Montomorency cherries, they believe the sleep benefits also stem from the ruby red pigments in tart cherry juice, known as proanthocyanidins.

The Daily Mail reports “These natural polyphenolic compounds are especially abundant in Montmorency tart cherries. In the study, tart cherry juice helped to increase 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. Tryptophan degradation is a known predictor of insomnia and is also related to inflammation, said co-authors Jack Losso and John Finley, professors in the School of Nutrition and Food Sciences at Louisiana State University Agricultural Center.

The research team believe it’s the unique combination of melatonin and tryptophan in Montmorency tart cherries that is likely contributing to the sleep benefits.