New study: Hotter nights, climate change, cause sleep loss with some affected more than others
According to a new study, sleep is impaired with temperatures over 50 degrees, and temps higher than 77 degrees reduce the chances of getting seven hours.
Data from the National Sleep Foundation finds that the optimal bedroom temperature for sleep is around 65 degrees Fahrenheit. But we may be getting fewer hours of "good sleepin’ weather" as the climate warms, according to a recent paper from researchers at the University of Copenhagen, Denmark.
Published in One Earth, the study finds that heat related to climate change could provide a “pathway” to sleep deprivation. The authors say the effect is “substantially larger” for those in lower-income countries. Hours of sleep decline when nighttime temperature exceeds 50 degrees, and temps higher than 77 reduce the chances of sleeping for seven hours by 3.5 percent. Even small losses associated with rising temperatures contribute significantly to people not getting enough sleep.
We’re affected by high temperatures at night because body temperature becomes more sensitive to the environment when slumbering. “Mechanisms that control for thermal regulation become more disordered during sleep,” explains Clete Kushida, a neurologist, professor of psychiatry at Stanford University and sleep medicine clinician.
The study finds that women and older adults are especially vulnerable. Worldwide, the elderly lost over twice as much sleep per degree of warming compared to younger people. This phenomenon was apparent between the ages of 60 and 70, and it increased beyond age 70. “The mechanism for balancing temperatures appears to be more affected with age,” Kushida adds.
Others disproportionately affected include those who live in regions with more greenhouse gas (GHG) emissions, which accelerate climate change, and people in hotter locales will lose more sleep per degree of warming, according to the study, with suboptimal temperatures potentially eroding 50 to 58 hours of sleep per person per year. One might think that those in warmer countries can adapt to the heat, but the researchers found no evidence for such adjustments. “We actually found those living in the warmest climate regions were impacted over twice as much as those in the coldest climate regions,” says the study's lead author, Kelton Minor, a Ph.D. candidate at the University of Copenhagen’s Center for Social Data Science.
Short sleep can reduce cognitive performance and productivity, increase absenteeism from work or school, and lead to a host of other physical and psychosocial problems. These issues include a compromised immune system, hypertension, depression, anger and suicide, say the study’s authors. According to a fact sheet by the U.S. Centers for Disease Control and Prevention, a third of U.S. adults already report sleeping fewer hours than the recommended amount, even though sufficient sleep “is not a luxury—it is something people need for good health.”
Equitable policy and planning are needed to ensure equal access to cooling technologies in a warming world.
Beyond global health, a sleep-deprived world will impact the economy as the climate warms. “Less productivity at work, associated with sleep loss or deprivation, would result in more sick days on a global scale, not just in individual countries,” Kushida says.
Unlike previous research that measured sleep patterns with self-reported surveys and controlled lab experiments, the study in One Earth offers a global analysis that relies on sleep-tracking wristbands that link more than seven million sleep records of 47,628 adults across 68 countries to local and daily meteorological data, offering new insight into the environmental impact on human sleep. Controlling for individual, seasonal and time-varying confounds, researchers found the main way that higher temperatures shorten slumber is by delaying sleep onset.
Heat effects on sleep were seen in industrialized countries including those with access to air conditioning, notes the study. Air conditioning may buffer high indoor temperatures, but they also increase GHG emissions and ambient heat displacement, thereby exacerbating the unequal burdens of global and local warming. Continued urbanization is expected to contribute to these problems.
Previous sleep studies have found an inverse U-shaped response to temperature in highly controlled settings, with subjects sleeping worse when room temperatures were either too cold or too warm. However, “people appear far better at adapting to colder outside temperatures than hotter conditions,” says Minor.
Although there are ways of countering the heat effect, some populations have more access to them. “Air conditioning can help with the effect of higher temperature, but not all individuals can afford air conditioners,” says Kushida. He points out that this could drive even greater inequity between higher- and lower-income countries.
Equitable policy and planning are needed to ensure equal access to cooling technologies in a warming world. “Clean and renewable energy systems and interventions will be needed to mitigate and adapt to ongoing climate warming,” Minor says. Future research should investigate “policy, planning and design innovation,” which could reduce the impact of sweltering temperatures on a good night’s sleep for the good of individuals, society and our planet, asserts the study.
Unabated and on its current trajectory, by 2099 suboptimal temperatures could shave 50 to 58 hours of sleep per person per year, predict the study authors. “Down the road, as technology develops, there might be ways of enabling people to adapt on a large scale to these higher temperatures,” says Kushida. “Right now, it’s not there.”
Chicken that is grown entirely in a laboratory, without harming a single bird, could be sold in supermarkets in the coming months. But critics say the doubts about lab-grown meat have not been appropriately explored.
Last November, when the U.S. Food and Drug Administration disclosed that chicken from a California firm called UPSIDE Foods did not raise safety concerns, it drily upended how humans have obtained animal protein for thousands of generations.
“The FDA is ready to work with additional firms developing cultured animal cell food and production processes to ensure their food is safe and lawful,” the agency said in a statement at the time.
Assuming UPSIDE obtains clearances from the U.S. Department of Agriculture, its chicken – grown entirely in a laboratory without harming a single bird – could be sold in supermarkets in the coming months.
“Ultimately, we want our products to be available everywhere meat is sold, including retail and food service channels,” a company spokesperson said. The upscale French restaurant Atelier Crenn in San Francisco will have UPSIDE chicken on its menu once it is approved, she added.
Known as lab-grown or cultured meat, a product such as UPSIDE’s is created using stem cells and other tissue obtained from a chicken, cow or other livestock. Those cells are then multiplied in a nutrient-dense environment, usually in conjunction with a “scaffold” of plant-based materials or gelatin to give them a familiar form, such as a chicken breast or a ribeye steak. A Dutch company called Mosa Meat claims it can produce 80,000 hamburgers derived from a cluster of tissue the size of a sesame seed.
Critics say the doubts about lab-grown meat and the possibility it could merge “Brave New World” with “The Jungle” and “Soylent Green” have not been appropriately explored.
That’s a far cry from when it took months of work to create the first lab-grown hamburger a decade ago. That minuscule patty – which did not contain any fat and was literally plucked from a Petri dish to go into a frying pan – cost about $325,000 to produce.
Just a decade later, an Israeli company called Future Meat said it can produce lab-grown meat for about $1.70 per pound. It plans to open a production facility in the U.S. sometime in 2023 and distribute its products under the brand name “Believer.”
Costs for production have sunk so low that researchers at Carnegie Mellon University in Pittsburgh expect sometime in early 2024 to produce lab-grown Wagyu steak to showcase the viability of growing high-end cuts of beef cheaply. The Carnegie Mellon team is producing its Wagyu using a consumer 3-D printer bought secondhand on eBay and modified to print the highly marbled flesh using a method developed by the university. The device costs $200 – about the same as a pound of Wagyu in the U.S. The initiative’s modest five-figure budget was successfully crowdfunded last year.
“The big cost is going to be the cells (which are being extracted by a cow somewhere in Pennsylvania), but otherwise printing doesn’t add much to the process,” said Rosalyn Abbott, a Carnegie Mellon assistant professor of bioengineering who is co-leader on the project. “But it adds value, unlike doing this with ground meat.”
Lab-Grown Meat’s Promise
Proponents of lab-grown meat say it will cut down on traditional agriculture, which has been a leading contributor to deforestation, water shortages and contaminated waterways from animal waste, as well as climate change.
An Oxford University study from 2011 concludes lab-grown meat could have greenhouse emissions 96 percent lower compared to traditionally raised livestock. Moreover, proponents of lab-grown meat claim that the suffering of animals would decline dramatically, as they would no longer need to be warehoused and slaughtered. A recently opened 26-story high-rise in China dedicated to the raising and slaughtering of pigs illustrates the current plight of livestock in stark terms.
Scientists may even learn how to tweak lab-grown meat to make it more nutritious. Natural red meat is high in saturated fat and, if it’s eaten too often, can lead to chronic diseases. In lab versions, the saturated fat could be swapped for healthier, omega-3 fatty acids.
But critics say the doubts about lab-grown meat and the possibility it could merge “Brave New World” with “The Jungle” and “Soylent Green” have not been appropriately explored.
A Slippery Slope?
Some academics who have studied the moral and ethical issues surrounding lab-grown meat believe it will have a tough path ahead gaining acceptance by consumers. Should it actually succeed in gaining acceptance, many ethical questions must be answered.
“People might be interested” in lab-grown meat, perhaps as a curiosity, said Carlos Alvaro, an associate professor of philosophy at the New York City College of Technology, part of the City University of New York. But the allure of traditionally sourced meat has been baked – or perhaps grilled – into people’s minds for so long that they may not want to make the switch. Plant-based meat provides a recent example of the uphill battle involved in changing old food habits, with Beyond Meat’s stock prices dipping nearly 80 percent in 2022.
"There are many studies showing that people don’t really care about the environment (to that extent)," Alvaro said. "So I don’t know how you would convince people to do this because of the environment.”
“From my research, I understand that the taste (of lab-grown meat) is not quite there,” Alvaro said, noting that the amino acids, sugars and other nutrients required to grow cultivated meat do not mimic what livestock are fed. He also observed that the multiplication of cells as part of the process “really mimic cancer cells” in the way they grow, another off-putting thought for would-be consumers of the product.
Alvaro is also convinced the public will not buy into any argument that lab-grown meat is more environmentally friendly.
“If people care about the environment, they either try and consume considerably less meat and other animal products, or they go vegan or vegetarian,” he said. “But there are many studies showing that people don’t really care about the environment (to that extent). So I don’t know how you would convince people to do this because of the environment.”
Ben Bramble, a professor at Australian National University who previously held posts at Princeton and Trinity College in Ireland, takes a slightly different tack. He noted that “if lab-grown meat becomes cheaper, healthier, or tastier than regular meat, there will be a large market for it. If it becomes all of these things, it will dominate the market.”
However, Bramble has misgivings about that occurring. He believes a smooth transition from traditionally sourced meat to a lab-grown version would allow humans to elide over the decades of animal cruelty perpetrated by large-scale agriculture, without fully reckoning with and learning from this injustice.
“My fear is that if we all switch over to lab-grown meat because it has become cheaper, healthier, or tastier than regular meat, we might never come to realize what we have done, and the terrible things we are capable of,” he said. “This would be a catastrophe.”
Bramble’s writings about cultured meat also raise some serious moral conundrums. If, for example, animal meat may be cultivated without killing animals, why not create products from human protein?
Actually, that’s already happened.
It occurred in 2019, when Orkan Telhan, a professor of fine arts at the University of Pennsylvania, collaborated with two scientists to create an art exhibit at the Philadelphia Museum of Art on the future of foodstuffs.
Although the exhibit included bioengineered bread and genetically modified salmon, it was an installation called “Ouroboros Steak” that drew the most attention. That was comprised of pieces of human flesh grown in a lab from cultivated cells and expired blood products obtained from online sources.
The exhibit was presented as four tiny morsels of red meat – shaped in patterns suggesting an ouroboros, a dragon eating its own tail. They were placed in tiny individual saucers atop a larger plate and placemat with a calico pattern, suggesting an item to order in a diner. The artwork drew international headlines – as well as condemnation for Telhan’s vision.
Telhan’s artwork is intended to critique the overarching assumption that lab-grown meat will eventually replace more traditional production methods, as well as the lack of transparency surrounding many processed foodstuffs. “They think that this problem (from industrial-scale agriculture) is going be solved by this new technology,” Telhan said. “I am critical (of) that perspective.”
Unlike Bramble, Telhan is not against lab-grown meat, so long as its producers are transparent about the sourcing of materials and its cultivation. But he believes that large-scale agricultural meat production – which dates back centuries – is not going to be replaced so quickly.
“We see this again and again with different industries, like algae-based fuels. A lot of companies were excited about this, and promoted it,” Telhan said. “And years later, we know these fuels work. But to be able to displace the oil industry means building the infrastructure to scale takes billions of dollars, and nobody has the patience or money to do it.”
Alvaro concurred on this point, which he believes is already weakened because a large swath of consumers aren’t concerned about environmental degradation.
“They’re going to have to sell this big, but in order to convince people to do so, they have to convince them to eat this product instead of regular meat,” Alvaro said.
Hidden Tweaks?
Moreover, if lab-based meat does obtain a significant market share, Telhan suggested companies may do things to the product – such as to genetically modify it to become more profitable – and never notify consumers. That is a particular concern in the U.S., where regulations regarding such modifications are vastly more relaxed than in the European Union.
“I think that they have really good objectives, and they aspire to good objectives,” Telhan said. “But the system itself doesn't really allow for that much transparency.”
No matter what the future holds, sometime next year Carnegie Mellon is expected to hold a press conference announcing it has produced a cut of the world’s most expensive beef with the help of a modified piece of consumer electronics. It will likely take place at around the same time UPSIDE chicken will be available for purchase in supermarkets and restaurants, pending the USDA’s approvals.
Abbott, the Carnegie Mellon professor, suggested the future event will be both informative and celebratory.
“I think Carnegie Mellon would have someone potentially cook it for us,” she said. “Like have a really good chef in New York City do it.”
In this week's Friday Five, breathing this way may cut down on anxiety, a fasting regimen that could make you sick, this type of job makes men more virile, 3D printed hearts could save your life, and the role of metformin in preventing dementia.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Here are the promising studies covered in this week's Friday Five, featuring interviews with Dr. David Spiegel, associate chair of psychiatry and behavioral sciences at Stanford, and Dr. Filip Swirski, professor of medicine and cardiology at the Icahn School of Medicine at Mount Sinai.
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Here are the promising studies covered in this week's Friday Five, featuring interviews with Dr. David Spiegel, associate chair of psychiatry and behavioral sciences at Stanford, and Dr. Filip Swirski, professor of medicine and cardiology at the Icahn School of Medicine at Mount Sinai.
- Breathing this way cuts down on anxiety*
- Could your fasting regimen make you sick?
- This type of job makes men more virile
- 3D printed hearts could save your life
- Yet another potential benefit of metformin
* This video with Dr. Andrew Huberman of Stanford shows exactly how to do the breathing practice.