Researchers have figured out ways to get better sleep at night

People around the world complain of insomnia and lack of sleep, which contributes to the growth of the sleeping pills market, which is worth more than $100 billion per year. Studies of circadian rhythms show how important it is to take into account the body's internal clock for quality sleep. However, scientists warn that online hacks and expensive tools are not always effective. This is reported by the journal Nature.

Unsuccessful attempts to fix the situation can have a negative impact, said Andrew McHill, a specialist in circadian rhythms and the University of Oregon Health and Science in Portland. According to him, this may prevent people from seeking help, and the situation may worsen. Instead, researchers are turning to lessons learned from circadian science, which over the past 50 years has revealed a network of biological clocks throughout the body.

This time measurement system ensures that physiological systems are ready to perform the right tasks at the right time, such as protecting themselves from pathogens, digesting food, and sleeping. But the circadian clock cannot work perfectly on its own. To stay in sync and function optimally, they need regular adjustments from sunlight, daily habits, and other cues.

Modern life is often not conducive to this, as people spend most of their time indoors, eat late at night and change their sleep patterns between workdays and weekends, effectively creating a jet lag. In this case, the consequences can be very serious. In the short term, circadian rhythm disturbances and lack of sleep can decrease cognitive function, mood, and reaction time, and in the long term, they can increase the risks of infections, diabetes, depression, dementia, cancer, heart disease, and premature death.

To improve sleep and health, McHill and other scientists emphasize three basic aspects — the contrast of light and dark, consolidating meal times, and maintaining a stable sleep pattern. According to him, a walk in the fresh air during the day and a reduction in light exposure in the evening can have a great effect.

Light provides the most powerful signal to the circadian system. Blue waves are especially effective. This is not an accident, as humans evolved outdoors, being under an open sky that is saturated with blue light. However, the common advice to avoid blue light at night is only part of the story.

In the 1990s and 2000s, a series of discoveries were made that proved the existence of photosensitive cells in the eyes that are directly involved in vision. Instead, the cells synchronize the body's biological clock by recording both the intensity and wavelength of light, as well as receiving data from rods and cones, and transmitting this data to the circadian "milk mechanism" in the brain.

Bright light is required for the system to work properly. Jamie Zeitzer, a sleep and circadian rhythms specialist at Stanford University in California, noted that people are pretty bad at determining the amount of light they receive. Ordinary home lighting may seem too bright for the eyes.

Bright blue light during the day synchronizes circadian rhythms and supports the nighttime surge of melatonin, a hormone that signals the body that it's time to sleep. It can also directly increase alertness and cognitive activity. However, the same light at night, from artificial sources and glowing screens, confuses the circadian system.

Blue light is the strongest disruptor, but there are enough photons of any color at night to change rhythms, suppress melatonin levels, and worsen sleep. According to Zeitner, exposure to light in the middle of the night is the most devastating. The circadian system is especially sensitive in the middle of sleep, when it least expects light. Research shows that even dim light, such as a light bulb in the hallway, can raise your nighttime heart rate and disrupt sleep.

Scientists say that the most important thing is the contrast: bright days and dark nights. Mariana Figueiro, director of the Center for Light and Health Research at the Icahn School of Medicine at Mount Sinai in New York, said that greater exposure to daylight helps strengthen circadian rhythms and improve sleep quality. One study among students found that their total number of hours in the daylight better predicts their bedtime and wake-up time than the light after dark.

A study in the UK, which covered almost 90,000 people, showed that 20% of people with low light levels are projected to live five years less than 20% of people with the healthiest habits, even taking into account income and physical activity. Andrew Phillips, a sleep health specialist at Flinders University in Australia and the author of the study, linked this to circadian rhythms that regulate every aspect of physiology.

It is difficult to achieve such a daily contrast in the modern world. Indoor lighting uses green waves, which are responsible for vision, but not for circadian rhythms. Energy consumption standards limit the brightness of these devices, and daylight coming through the windows dissipates quickly. Energy-saving window panes and eyeglass lens coatings that block blue light reduce the number of photons more. Aging exacerbates the problem, as the lenses of the eyes turn yellow over time and filter out more blue light.

It is recommended to spend more time outdoors, sit by windows and use LED lamps that simulate daylight during the day. In the evening, you should reduce the brightness of the lamps and turn off the screens, or use applications that darken the screens or switch them to a warmer spectrum. According to scientists, the exact recipe is individual. Even people of the same age can vary significantly in their reactions to the same light, perhaps due to characteristics such as gender or eye color. However, when the light comes from the screens, the content can have the same meaning as the light itself.

Calorie intake is also associated with circadian rhythm and sleep. According to the material, the human liver at 10:00 and 22:00 are different organs, the same can be said about other parts of the body that process food. Hunger hormones, digestive enzymes, and insulin also have their own rhythms.

Emily Manugyan, a circadian rhythm specialist at the Salk Institute for Biological Research in San Diego, California, says that people are simply not adapted to eating at any time of the day. It is noted that later consumption of food causes a rush of blood to the intestines and an increase in body temperature, as well as increases glucose levels. Experts suggest following the saying "eat like a king in the morning, like a prince in the afternoon, and like a peasant at dinner."

The quality of the food consumed is also important. For example, diets high in sugar and saturated fat make sleep easier and more fragmented, and caffeine lingers in the body for several hours. The consumption of plant foods can help improve sleep. If snacking before bedtime is unavoidable, Marie-Pierre Saint-Onge, a specialist in nutrition, sleep and circadian rhythms from Columbia University in New York, recommends something simple and easily digestible.

In addition, experts emphasize the importance of sleeping at the right time. The circadian system regulates sleep in conjunction with the homeostat, a separate system that affects sleepiness. Its alignment with the system means the need to stay asleep and wake up at the same time in accordance with biological characteristics. Researchers believe that at least 80% of workers and students rely on alarm clocks — that is, they live in contradiction with their biology.

Phillips and his colleagues found that unstable sleep patterns predict mortality better than the total number of hours. Another study co-authored by him notes that people with heart failure and irregular sleep patterns are at twice the risk of dying than those who follow a regular regime. According to the expert, focusing on one factor can help others get out of their seats, and fixing sleep time through a regular diet can make it easier to get morning light and avoid nighttime.

It is recommended to find a compromise. According to the publication, eating throughout the day can reduce many risks, including mood disorders and blood sugar problems. Other behavioral cues, such as exercise, can also be used. At the same time, life requires flexibility, so you can periodically indulge in late dinners or extra hours of sleep on non-working days.

On September 30, doctor Ekaterina Dmitrenko shared ways to improve sleep quality. According to her, most adults need to sleep 7-9 hours a night or 7.5 hours on average. The specialist clarified that sleeping less than seven hours a day is a health risk, and sleeping too long (9-10 hours) may indicate illness. Dmitrenko noted that it is important not only the quantity, but also the quality of sleep, including regularity, continuity and balance of phases.

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