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Hunters and gatherers tend to have shorter sleep durations compared to industrialized individuals.

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Members of the Namibian HIMBA community get an average of 5.5 hours of sleep at night

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Unlike our ancestors who lived in technologically advanced times, there is much written about how modern lifestyles mean that we no longer get enough sleep. However, an analysis of 54 sleep studies conducted around the world has shown that people in small, non-industrial societies actually sleep less than people in industrialized communities.

“Everyone I talk about in Canada and the US are talking about how bad their sleep is.” Leela Mackinnon At Toronto Mississauga University, Canada. “The numbers don’t show that.”

It is often assumed that the rise of gadgets like big screen televisions and smartphones means that people today are less sleepy than in the recent past.

However, many studies reporting sleep declines over the past few decades are based on asking people how long they spend sleep. This is an unreliable measure. Even using this method, The results are mixedmany studies have found that there is no change or even an increase in sleep duration.

Studies based on more reliable measurements, such as using physical activity monitors and electrodes to monitor brain waves, have not declined over the last few decades. For example, we found a 2016 review of 168 studies. There is no decline Sleep period for the past 50 years.

However, these studies have been conducted in developed countries and reveal the question of whether people had more sleep before industrialisation. Wrist-based activity monitors are now available, making it easier to study sleep in a non-industrial society.

Such studies have revealed an incredible short period of sleep. For example, among hunter-gatherers, Sun sleeps on average 6.7 hours per night, Hatza sleeps 6.2 hours, and Bayaka sleeps 5.9 hours per night. The shortest time ever found is 5.5 hours of sleep in the HIMBA community in Namibia, a herdsman of nomadic livestock.

McKinnon and her colleagues David SamsonUniversity of Toronto, University of Mississauga, is also involved in several such research. They now compare sleep habits in industrialized societies, including the US, Australia and Sri Lanka, with people from small, non-industrial communities, including the Amazon, Madagascar and the Pacific indigenous people.

Overall, the analysis is based on 54 studies that include direct measures of sleep in people over 18 years of age without serious health conditions. In total, only 866 people are involved in these studies, but the dataset is the most comprehensive to date, says Samson. “It’s the best now.”

Overall, these individuals slept on average 6.8 hours, while in non-industrial societies the average was 6.4 hours, while in industrial societies it was 7.1 hours.

The two also found that people from the industrial world were asleep for 74% of their time in bed.

McKinnon and Samson also evaluated the regularity of people’s circadian rhythms using a measure called the circadian function index, where the score of 1 is perfect. In non-industrialized communities, the average was 0.7 compared to 0.63 in industrial societies.

Samson attributes the higher period of sleep and increased sleep efficiency in industrialized societies to conditions that encourage sleep more. “We see that we have some real benefits from the safety and security of our sleep scene,” he says. “There’s no need to dodge the night or predators with rival human groups.”

Conversely, people in industrial areas are less exposed to clues that help to maintain a circadian rhythm, such as low night temperatures and bright daylight exposure. Although they did not appreciate this, both MacKinnon and Samson said that a low normal circadian rhythm would have a negative effect explaining why many people perceive their sleep as poor. I doubt there is a possibility of giving it.

What is not clear from the paper says that individuals in these 54 studies are representatives of the overall population. Nathaniel Marshall At Macquarie University in Sydney, Australia. “Special sampling is required to make a statement about epidemiological prevalence,” he says.

Samson said he looked into whether large sample sizes could change results, and concluded that there was no significant difference.

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Source: www.newscientist.com

Here’s why people who stay up late tend to have better cognitive abilities than those who rise early

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Struggle to wake up in the morning? Feel more alert as the day goes on? Have more energy in the evenings? You might be an “evening” chronotype, meaning your body clock is most active later in the day.

Scientists have linked being a night owl to negative outcomes like higher chances of depression and displaying Dark Triad personality traits. However, a new British study shows that evening chronotypes may have superior cognitive function compared to morning types.

Respecting your natural body clock, managing light exposure, prioritizing sleep, and using naps wisely can help night owls thrive in a world that often favors early risers.

Honor your chronotype

It’s essential to honor your evening tendencies as they reflect your biological characteristics. Certain genetic factors and age play a role in determining your sleep preferences.

Exposure to light can change your body clock

Getting sunlight in the morning and avoiding it later in the day can help align your body clock. Blue light exposure should also be limited, especially at night, to support healthy sleep patterns.

Make sure you get enough sleep

Respecting your chronotype is crucial for overall health and well-being. Lack of sleep, stress, and a misaligned body clock can lead to various health problems in the long term.

Use naps wisely

Short naps taken in the late morning or early afternoon can improve performance later in the day. The coffee-nap trick, where you drink a cup of coffee before a short nap, can help you wake up feeling refreshed and alert.

By following these strategies, night owls can thrive in a world that often prioritizes morning routines and early risers.

About our experts

Professor Russell Foster is a Director at the Nuffield Institute of Ophthalmology and the Institute of Sleep and Circadian Neuroscience at the University of Oxford.

Professor Martha Mellow is a researcher in molecular chronobiology at the Ludwig Maximilian University in Munich.

Source: www.sciencefocus.com

Labradors with a mutation that causes starvation tend to easily gain weight

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About a quarter of Labradors have a mutation in the POMC gene that induces starvation.

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Labradors and flat-coated retrievers, two dog breeds, may be more susceptible to being overweight because they carry mutations that cause them to feel hungry between meals and slow their metabolic rates. “It's a double whammy,” he says. Eleanor Laffan at Cambridge University.

mutations that affect genes called POMCwhich affects about a quarter of Labradors and two-thirds of flat-coated retrievers, but does not affect other breeds.

Discovered in 2016, it was found to alter pathways in the brain associated with weight regulation, but it was unclear exactly how it affected eating habits.

To find out, Laffan's team conducted a “boxed sausage” test on 87 pet Labradors. In this test, dogs were able to see and smell sausages in an impenetrable container. The Labrador dog, in which he had one copy of the mutation, continued to try to open the box much longer than the dog without it.

However, in another test in which dogs were given a can of food every 20 minutes until they ran out of food, all dogs ate the same amount of food, regardless of whether they had the genetic mutation or not. This shows that the mutation affects appetite in a specific way, by increasing hunger levels between meals, Laffan says.

The researchers also measured the resting metabolic rates of flat-coated retrievers while they slept and found that dogs with two copies of the mutation had metabolic rates that were about a quarter lower than other dogs.

Laffan said the effect would be expected to be the same in both breeds, but in a second experiment flat-coated retrievers were more likely to carry both of the mutations than Labradors. He wanted to find out.

Laffan said many other genes probably influence dog weight, just as they do in humans.

Dan O'Neill Researchers from the Royal College of Veterinary Medicine say owners of overweight dogs should avoid giving treats as a way to show affection and instead give their dogs other forms of attention. “You can also replace that snack with a walk,” he says.

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Source: www.newscientist.com