Oct. 6, 2022 — The comfort of feeling snug and secure with the help of a weighted blanket can help promote sleep by inducing a release of melatonin, a hormone associated with sleep, such as a study with young, healthy participants suggests.
“We all know that when we want to relax a little or need support from others, it’s really good when they hug us,” says Christian Benedict, PhD, associate professor of pharmacology at Uppsala University in Uppsala, Sweden.
“And I think it’s kind of similar with a weighted blanket, because the blanket activates our sensory system and that system sends information to the brain, where it affects certain structures that play a role in regulating melatonin,” he says.
“So the body feels ready – now I’m protected so I can relax – and that signals the brain that we’re ready to initiate sleep, which is why it boosts the melatonin signal,” says Benedict.
The study was published online on Monday Journal of Sleep Research.
Melatonin rises higher with heavier ceilings
The study involved 26 young men and women who did not have insomnia. Participants went through two experimental sessions – the first visit to the laboratory served as an “adjustment night” and the second for the experiment. The adaptation night was designed to help participants adapt to the experimental environment, the authors say. Saliva was collected every 20 minutes between 10 p.m. and 11 p.m., while participants’ sleepiness was rated every 20 minutes using the Karolinska sleepiness scale both before the lights were turned off and between 7 a.m. and 8 a.m. the next morning.
Sleep duration was also recorded using a special wearable device that measures many physiological indicators of sleep.
The researchers said they focused on “total sleep duration as an outcome” for this study and found that melatonin increases in the saliva samples they collected were greater between 10 p.m. and 11 p.m. when participants used the weighted blanket.
There was also an initial but short-lived increase in oxytocin levels when participants used the weighted blanket versus the light blanket, but it wasn’t statistically significant, the researchers said. (Oxytocin is the so-called “love” hormone that controls aspects of human behavior, including childbirth and breastfeeding.)
But the differences in measurements of sleepiness between the two blanket states were not different. There were also no significant differences in total sleep time when participants used the weighted blanket versus the light blanket.
But as Benedict points out, people respond differently to melatonin. For example, children with attention deficit hyperactivity disorder (ADHD) could benefit, as could older people who no longer produce enough melatonin themselves.
Overall, most studies suggest that melatonin itself does not promote sleep. Melatonin prepares the body and brain for the biological event of the night, which includes sleep, but it works through a relatively strong placebo effect: people believe melatonin helps them sleep and believe it does causes, says Benedict.
And just because the body makes its own melatonin doesn’t necessarily make it safe to use melatonin supplements, says Benedict. For example, when people eat and have a lot of melatonin in their system, the melatonin tells the pancreas to stop producing insulin in response to food, as it normally would. As a result, they run the risk of having high blood sugar levels, which can be harmful over time. There is also a risk of children snagging their parents’ melatonin stores, and melatonin can prove to be extreme harmful to children.
Weighted blankets are widely used and sold for therapeutic reasons. People should test the blankets before deciding on one; If a blanket is too heavy, the effect can be suffocating instead of feeling cozy and safe.
Benedict also warns that heavy blankets sold for therapeutic purposes don’t come cheap — they cost up to $250 in Scandinavia — which is why doctors might still want to recommend them for their patients with insomnia, assuming they can afford the ceiling. Alternatively, people might consider buying more than one lightweight blanket and adding weight as needed, he suggests.
“Our study is the first to suggest that weighted blankets may lead to greater release of melatonin [but] future studies should investigate whether the stimulatory effect on melatonin secretion persists when a weighted blanket is used for long periods of time,” the study authors write.
It’s not clear whether the increase in melatonin observed in the study makes any therapeutic sense, they said.