Melatonin helps regulate bodily cycles and levels in milk are very high at night. Claire O'Connellreports on dairy farmers who have changed their milking routines
A FEW MORNINGS a week, Cork dairy farmer Gerald Burns gets up and milks his cows in the dark at 3am. It might sound like a bizarre thing to do, but there is method in his madness. Night-time milk produced by cows is rich in melatonin, which has been shown to help improve sleep quality in people.
Melatonin, a hormone produced by the brain that helps regulate 24-hour bodily cycles, occurs naturally in milk. But levels are particularly high in night-time milk, according to Finnish research.
"Melatonin is high in blood during the night and low during the day in all mammals, including the cow and man, and melatonin is secreted into milk according to its concentration in blood," explains Prof Maija Valtonen. She has recently retired from the University of Kuopio in Finland, where her work examined night-time milk and its effects. "It seems that high melatonin in milk at night helps the offspring to develop its own daily rhythm, which is not fully developed at birth."
She has been involved in the development of commercially available night-time milks, and her studies on melatonin-enriched milk found that drinking it improved the quality of sleep in elderly people, and increased their daytime activity.
"Using melatonin-rich milk regularly, about half a litre a day, improved the quality of sleep by decreasing the wakening times during the sleep, consequently improving sleep efficiency and daytime activity," says Valtonen.
Young people might also benefit from drinking the sleepy milk if stress is interfering with slumber, she adds. "If they have sleep difficulties and decreased melatonin secretion, night milk may increase their sleep quality."
However, Valtonen draws the line at using the drink to treat jet lag. "The concentration of melatonin is not high enough in night-time milk to have any acute effect on jet lag. Jet lag should be treated with short-term use of pharmaceutical doses of melatonin," she says.
So where does the farm in north Cork come in? "My father stumbled across Valtonen's work a few years ago," says Burns. "So he milked early one morning and sent a sample to California to get tested."
The results showed the night-time milk had four times the melatonin of regular milk.
Now Burns or his colleague gets up at uncivilised hours three times a week to milk the 150-strong herd of Fresians at Ardrahan Farm, ensuring that the milking parlour is kept dark, because light could lower the cows' melatonin levels.
Valtonen visited the farm last February and signed off on the process, granting them the first licence to produce melatonin-rich milk in Ireland. Their Lullaby brand is now carried by three supermarket chains and other outlets around the country at around €1.99 per litre. Burns himself drinks night-time milk to steel himself for the 3am starts. "The night before you do it, around 8pm or 9pm you would drink a pint of it," he says.
To date, feedback on the product has been favourable, according to Burns. "We've never had anyone ring us up and complain it doesn't work," he says.