Weighted blankets are growing in popularity as people share their experience of better sleep with their friends and family. Previous studies have shown heavy blankets can reduce insomnia and now new research from Uppsala University in Sweden shows weighted blankets increase melatonin levels during sleep.
Melatonin is a hormone the body naturally produces in response to darkness and it is an important factor in sleep. Armed with the knowledge heavy blankets help with insomnia but not understanding the reasoning behind it, Uppsala researchers worked with a group of 26 young people on the study and published their findings in the Journal of Sleep Research.
Scientists wanted to know what effect a weighted blanked had on the production of hormones like melatonin and oxytocin. They were also curious to know if the blankets were able to reduce the activity of stress symptoms in the body.
This was done by repeatedly collecting saliva samples from study participants while either using a weighted blanket, which was equivalent to 12% of the person’s body weight, or a light blanket. The samples allowed researchers to measure melatonin, oxytocin, cortisol and the activity of the sympathetic nervous system, which controls the fight-or-flight reaction.
"Using a weighted blanket increased melatonin concentrations in saliva by about 30%," said Elisa Meth, first author and Ph.D. student at the Department of Pharmaceutical Biosciences at Uppsala University. "However, no differences in oxytocin, cortisol, and the activity of the sympathetic nervous system were observed between the weighted and light blanket conditions."
Scientists are hoping more research on the subject will answer some questions that have arisen in their minds such as how long does the increase last. They want to know if the increase is experienced every time the blanket is used or if the levels diminish over time as the body gets used to the blanket.
"Our study may offer a mechanism explaining why weighted blankets may exert some therapeutic benefits, such as improved sleep," said senior author Christian Benedict, Associate Professor of Pharmacology at the Department of Pharmaceutical Biosciences at Uppsala University. "However, our findings rely on a small sample and investigated only the acute effects of a weighted blanket. Thus, larger trials are needed, including an investigation of whether the observed effects of a weighted blanket on melatonin are sustained over longer periods."