October 6, 2022 — The comfort of feeling comfortable and secure using a weighted blanket may help promote sleep by inducing a release of the hormone melatonin, a hormone associated with sleep, according to a study in young participants in good health.
“We all know that if we want to relax a bit or need support from others, it’s really good if they give us a hug,” says Christian Benedict, PhD, associate professor of pharmacology at the University. from Uppsala to Uppsala, Sweden.
“And I think it’s kind of similar with a weighted blanket because the blanket activates our sensory system, and that system relays information to the brain where it impacts certain structures that play a role in regulating the melatonin,” he says.
“So the body feels ready – now I’m protected so I can relax – and it 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 Monday in the sleep research journal.
Melatonin increases more with heavier coverage
The study involved 26 young men and women who did not have insomnia. Participants underwent two experimental sessions – the first visit to the lab to serve as a “fit-in” night and the second for experimentation. The adaptation evening was intended to help participants adapt to the experimental setting, explain the authors. Saliva was collected every 20 minutes between 10 p.m. and 11 p.m., while participants’ sleepiness was also assessed every 20 minutes using the Karolinska Sleepiness Scale before lights out 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 were focusing on “total sleep time as an outcome” for this study, noting that increases in melatonin in the saliva samples they collected were greatest 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 compared to the light blanket, but this was not statistically significant, the researchers said. (Oxytocin is the so-called “love” hormone that controls aspects of human behavior, including childbirth and lactation.)
But the differences in measures of sleepiness between the two general conditions were not different. There were also no significant differences in total sleep time when participants used the weighted blanket compared to the light blanket.
But as Benedict points out, people have a variable response to melatonin. For example, children with attention deficit hyperactivity disorder (ADHD) could benefit, as well as older people who no longer produce enough melatonin on their own.
Overall, most studies suggest that melatonin itself does not promote sleep. Melatonin prepares the body and brain for the biological event of nighttime, which includes sleep, but it works through a relatively strong placebo effect: people believe melatonin will help them sleep and believe it does that it is so, said Benedict.
And just because the body makes its own melatonin, it’s not necessary to use melatonin supplements safely, says Benedict. For example, if people eat and have a lot of melatonin in their system, the melatonin tells the pancreas to stop making insulin in response to food like it normally would. As a result, they run the risk of having high blood sugar, which over time can be harmful. There is also a risk that children will enter their parents’ melatonin stores, and melatonin can be extremely harmful to children.
Weighted blankets are widely available and are sold for therapeutic reasons. People should test covers before settling on them; if a blanket is too heavy, the effect can feel suffocating instead of feeling comfortable and secure.
Benedict also warns that the heavy blankets sold for therapeutic reasons aren’t cheap — in Scandinavia they cost up to $250 — so doctors might still want to recommend them to their insomnia patients provided they can. afford the cover. Alternatively, people could consider buying more of a lightweight blanket and pile on the 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 determine whether the stimulating effect on melatonin secretion persists when using a weighted blanket over longer periods of time,” the study authors write.
It’s unclear whether the increase in melatonin seen in the study is therapeutically useful, they said.