Nodding off

时间:2019-03-07 01:02:00166网络整理admin

By Robert Adler IN My Fair Lady,Liza Doolittle yearns for a warm face, warm hands and warm feet. Now it turns out these are just the ticket for a quick trip to slumberland. Kurt Kräuchi and his colleagues at the Psychiatric University Clinic in Basel wondered which factors affect how quickly people go to sleep. So they monitored heart rates and body temperatures of 18 young men as they dozed off. Some men had taken melatonin in the evening, and others had a carbohydrate-rich dinner. The results showed that melatonin, a hearty meal or simply switching off the lights and lying down increased blood flow in the volunteers’ hands and feet, making them warmer. And those with the highest blood flow rates went to sleep quickest (Nature, vol 401, p 36). Vigorous blood flow also meant the body’s core temperature dropped. “This is the necessary trigger for sleep onset,” concludes Anna Wirz-Justice, one of the researchers. Jim Horne, a sleep researcher at Loughborough University, Leicestershire,