According to a recent study published in the journal one earthGlobal warming would mean we lose an average of 44 hours of sleep per year. An alarming figure that continues to grow. But concretely, why is this climate change affecting our sleep? We take stock with a health professional.
“If climate change continues, it will have a major impact on our health in general and on sleep in particular”† Here are the words of Dr. José Haba-Rubio, physician affiliated with the Center for Research and Sleep Research (CIRS) of the Vaudois University Hospital (Switzerland). In question, the episodes of heat that would disrupt our nights.
This is emphasized by a European study led by Danish and German scientists. To arrive at this alarming assessment, these researchers collected data from 48,000 people from 68 countries who were equipped with connected bracelets that measure their sleep cycles. Between 2015 and 2017, a total of 7 million daily recordings were made. As a result, this illuminating study shows that we lose about 44 hours of sleep a year and it’s not going to get better.
Why does heat affect sleep?
dr. José Haba-Rubio explains to POSITIVR that our sleep is partly regulated by our biological clock (the suprachiasmatic core) which is responsible for marking the rhythms (such as the sleep-wake rhythm or the rhythm of body temperature).
“Our sleep closely follows the rhythm of temperature. We always fall asleep when our body temperature starts to drop in the evening. But if the temperature is higher, it will be more difficult to fall asleep.
“Temperature is certainly one of the conditions in our environment that is likely to have a major impact on our sleep when it deviates from its usual level”† And for good reason, when we leave this “thermal niche”, our bodies react to maintain a constant temperature. But when we sleep, the thermoregulatory mechanisms are less effective, and our brains respond by “commanding” us to wake up to reactivate these mechanisms. Without them, our body cannot maintain a stable temperature…
“Sleep is therefore shorter, more fragmented, with more light sleep and less deep/REM sleep when it is very hot or very cold.”
Among the people most affected by this global warming-related insomnia are seniors, as with age, sleep becomes more fragile and we wake up more often during the night. This also applies to postmenopausal women. But sleep varies from person to person, and some are more sensitive to environmental factors. for dr. Jose Haba Rubio, “The inter-individual differences are very large and there are many factors, other than age and gender, that can play a role.”
Sleep deprivation: what consequences for our health?
As we know, good sleep is one of the prerequisites for good physical and mental health. dr. José Haba-Rubio recalls that: “Numerous epidemiological studies have shown that a short or poor night’s sleep is associated with an increased risk of diseases, such as depression, or cardiovascular and metabolic diseases (diabetes, obesity…).”
Sleep ? One more reason to fight against the worsening of global warming.