Do you sleep well? What kind of sleeper are you?

Learn more about the importance of sleep and its relationship to health.

SLEEP, THE MIRACLE DRUG THAT RESTORES YOUR BODY AND MIND

In sleep laboratories around the world, researchers study the body's response to rest. They analyze the correlation between sleep and mood, weight control, and cognitive function. Groups of people can share similar sleep characteristics. Shift workers, for example, are known to suffer from a range of metabolic disorders and have a higher risk of heart disease and depression.

We don't get enough sleep:

And yet, less than half of all adults get enough sleep. Doctors write more than 40 million prescriptions for sleep aids each year. Many people rely on these medications, regardless of the side effects.

Despite all these sleep issues, very few people understand that sleep is the cornerstone of a healthy lifestyle. If you don't sleep well, no diet will make you lose weight, no exercise program will get you fit, and there is almost no way to achieve calm in the face of ordinary stress.

Restoring Sleep:

From a chronobiological perspective, sleep is the reset button for the brain and body. The brain clears the debris from the day's activities, and many of the body's systems repair and rebuild while you rest. This is why lack of sleep can cause so many health and mood problems. But sleep is also the time when the body resets its daily circadian rhythm. Your body resets its clock overnight. When you stay up late, you set the clock to the wrong time, and your body won't crave sleep for another 24 hours. Ideally, you should fall asleep before 10:30 p.m. If that sounds impossible, you may not be preparing for sleep.

Ayurveda recognizes that not everyone is exactly the same. People have different physical characteristics, thinking styles, and ways of experiencing the world. Your sleep habits reflect this. To find the best solution for getting the rest your body needs, consider what type of sleeper you are. Strong sleepers tend to fall asleep relatively easily but wake up slowly. They need help getting going in the morning and incorporating enough physical movement into their daily lives to stay alert throughout the day. They should also avoid calories late in the day, as you may experience insomnia when you eat too late.

Variable Sleepers

Variable sleepers sleep well until something goes wrong. They tend to be organized and have a regular routine that helps them stay healthy until emotional upset or work-related stress keeps them awake. They often work at night because they are driven; they wait for fatigue to take over. They often exercise too much or too late in the day, and the activity keeps them awake when their body wants to sleep.

Light Sleepers

If you're a light sleeper, your mind is racing all the time. You have a million ideas and tend to be creative, but you're also sensitive to anxiety. You struggle to fall asleep most nights and then wake up frequently during the night. You need some extra help establishing a bedtime routine that relaxes your body and calms your mind. Eliminating all electronic devices at night (including the TV) is important to you. You may benefit from meditation and herbal remedies to promote sleep. Sleep is part of your routine, but it's easy for you to take it for granted. Be mindful of the type of sleep you routinely get and follow these tips to ensure you get the rest you need. Sound sleep!

RELATIONSHIP BETWEEN SLEEP QUALITY AND MOOD

Sleep disturbances play an important role in daily affect and vice versa. Daily sleep quality and mood are related, and the effect of sleep quality on mood is significantly greater than the reverse. SLEEP DEPRIVATION AND ITS IMPACT ON COGNITIVE PERFORMANCE.

Today, prolonged wakefulness is a widespread phenomenon. However, in the field of sleep and wakefulness, several unanswered questions remain. Prolonged wakefulness can be due to acute total sleep deprivation (SD) or chronic partial sleep restriction. Although the latter is more common in everyday life, the effects of total SD have been more thoroughly examined. Both total and partial SD induce adverse changes in cognitive performance. First, total SD impairs attention and working memory, but it also affects other functions, such as long-term memory and decision-making. Partial SD is found to influence attention, especially vigilance. Studies on its effects on more demanding cognitive functions are lacking. Coping with SD depends on several factors, especially aging and gender. Interindividual differences in responses are also substantial. In addition to coping with SD, recovery from it also deserves attention. Cognitive recovery processes, although insufficiently studied, appear to be more demanding in partial sleep restriction than in total SD. A person's quality of life can be impaired due to many different reasons. An important but underestimated cause of this is sleep loss (National Sleep Foundation 2007). Working hours are constantly increasing along with an emphasis on active leisure time. In certain jobs, people face sleep restrictions. Some professions such as healthcare, security, and transportation require working at night. In such fields, the effect of acute total sleep deprivation (SD) on performance is crucial. Furthermore, people tend to overextend their capacity and compromise their nighttime sleep, thus becoming chronically sleep deprived.

When considering the effects of sleep loss, the distinction between total and partial DS is important. While both conditions induce several negative effects, including impairments in cognitive performance, the underlying mechanisms appear to be somewhat different. Particularly, results in DS recovery have suggested different physiological processes. SLEEP AND SLEEP LOSS

The need for sleep varies considerably between individuals (Shneerson 2000). The average sleep duration is between 7 and 8.5 h per day (Kripke et al. 2002; Carskadon and Dement 2005; Kronholm et al. 2006). Sleep is regulated by two processes: a homeostatic process S and a circadian process C (e.g., Achermann 2004). The homeostatic process S depends on sleep and wakefulness; the need for sleep increases as wakefulness continues. The circadian process C theory suggests control by an endogenous circadian pacemaker, which affects the thresholds for the onset and offset of a sleep episode. The interaction of these two processes determines the sleep/wake cycle and can be used to describe fluctuations in alertness and vigilance. Although revised "three-process models" have been suggested (e.g., Akerstedt and Folkard 1995; Van Dongen et al 2003b; Achermann 2004), this classical model is the primary one used for study designs in SD research.

Sleep is considered important for bodily restoration, such as energy conservation, thermoregulation, and tissue recovery (Maquet 2001). Furthermore, sleep is essential for cognitive performance, especially memory consolidation (Maquet 2001; Stickgold 2005).

Sleep loss, on the other hand, appears to activate the sympathetic nervous system, which can lead to an increase in blood pressure (Ogawa et al. 2003) and increased cortisol secretion (Spiegel et al. 1999; Lac and Chamoux 2003). The immune response may be impaired, and metabolic changes such as insulin resistance may occur (for a review, see Spiegel et al. 2005). People who are exposed to sleep loss generally experience decreased cognitive performance and changes in mood (for meta-analyses, see Pilcher and Huffcutt 1996; Philibert 2005).

Cognitive performance measured in SD studies has included several domains. The most frequently assessed functions include various functions of attention, working memory, and long-term memory. Visuomotor and verbal functions, as well as decision-making, have also been assessed. The effects of sleep deprivation on cognitive performance depend on the type of task or modality involved (e.g., verbal, visual, or auditory). In addition, task demands and time on task may play a role.

Executive processes in working memory play a role in certain attentional functions, such as sustained attention (Baddeley et al. 1999), referred to here as vigilance. Both attention and working memory are linked to the functioning of the frontal lobes (for a review, see Naghavi and Nyberg 2005). Since frontal brain areas are vulnerable to DS (Harrison et al. 2000; Thomas et al. 2000), it can be assumed that both attention and working memory are impaired during prolonged wakefulness.

The decline in attention and working memory due to Down syndrome is well established. Vigilance is particularly affected, but declines are also observed in several other attention tasks. These include measures of auditory and visuospatial attention, serial addition and subtraction tasks, and various reaction time tasks.

SLEEP DURATION AS A RISK FACTOR FOR CARDIOVASCULAR DISEASE

Sleep loss is a common condition in developed countries, with evidence showing that people in Western countries sleep an average of only 6.8 hours (h) per night, 1.5 hours less than a century ago. Although the effects of sleep deprivation on our organs have been obscure, recent epidemiological studies have revealed relationships between sleep deprivation and hypertension (HT), coronary heart disease (CHD), and diabetes mellitus (DM). Because sleep deprivation increases sympathetic nervous system activity, this increased activity serves as a common pathophysiology for HT and DM. Adequate sleep duration may be important for preventing cardiovascular disease in modern society.

SLEEP AND IMMUNE FUNCTION

Sleep and the circadian system exert a strong regulatory influence on immune functions. Investigations of the normal sleep-wake cycle showed that immune parameters such as the number of undifferentiated naive T cells and proinflammatory cytokine production peak during early nocturnal sleep, while the circulating number of immune cells with immediate effector functions, such as cytotoxic natural killer cells, as well as anti-inflammatory cytokine activity, peak during daytime wakefulness. Although it is difficult to fully dissect the influence of sleep from that of the circadian rhythm, comparisons of the effects of nocturnal sleep with those of 24-hour wake periods suggest that sleep facilitates T cell extravasation and their potential redistribution to lymph nodes. Furthermore, such studies revealed a selective influence of sleep on cytokines that promote the interaction between antigen-presenting cells and helper T cells, such as interleukin-12. Sleeping the night after experimental hepatitis A vaccines produced a strong and persistent increase in the number of antigen-specific Th cells and antibody titers. Together, these findings indicate a specific role of sleep in the formation of immunological memory. This role appears to be associated in particular with the slow-wave sleep stage and the accompanying proinflammatory endocrine milieu, characterized by high levels of growth hormone and prolactin and low concentrations of cortisol and catecholamine.

BLUE LIGHT EMITTED BY SCREENS HARMFUL TO OUR SLEEP

Short-wavelength blue light emitted by the screens we view impairs the duration, and even more so, the quality of our sleep. This is the conclusion of a new study conducted by the University of Haifa and Assuta Sleep Clinic. The study also found that looking at screens that emit red light causes no harm, and sleeping after exposure to it is similar to normal sleep. "The light emitted by most screens (computers, smartphones, and tablets) is blue light, which harms the body's cycles and our sleep," explains Professor Abraham Haim of the University of Haifa, one of the study's authors. "The solution should be to use existing filters that prevent the emission of this light."

Previous studies have already shown that looking at screens before going to sleep harms our sleep. Exposure to blue light with wavelengths of 450-500 nanometers has also been found to suppress the production of melatonin, a hormone secreted at night that is linked to normal body and sleep cycles. The new study, published in the journal Chronobiology International, was conducted by researchers Prof. Abraham Haim, Dr. Merav Cohen-Zion, and Prof. Yaron Dagan. The researchers sought to examine whether there are any differences in sleep patterns after exposure to blue screen light compared to red light before sleep, and furthermore, to find which is more disruptive.

wavelength or intensity?

The study participants were 19 healthy individuals between the ages of 20 and 29 who were unaware of the study's purpose. In the first part of the trial, participants wore an actigraph (a device that provides an objective measurement of the time an individual falls asleep and wakes up) for one week. They also completed a sleep diary and a questionnaire about their sleep habits and sleep quality. In the second part of the trial, which took place at the Assuta Sleep Lab, participants were exposed to computer screens from 9 p.m. to 11 p.m.—the times when the pineal gland begins to produce and excrete melatonin. Participants were exposed to four types of light: high-intensity blue light, low-intensity blue light, high-intensity red light, and low-intensity red light. After exposure to light, they were connected to instruments that measure brain waves and can determine the sleep stages a person experiences throughout the night, including awakenings not noticed by the participants themselves. In the morning, the participants completed several questionnaires related to their feelings.

On average, exposure to blue light reduced sleep duration by approximately 16 minutes. Furthermore, exposure to blue light significantly reduced melatonin production, while exposure to red light showed a level of melatonin production very similar to normal. The researchers explain that impaired melatonin production reflects a substantial disruption of the body's natural mechanisms and biological clock. For example, it was found that exposure to blue light prevents the body from activating the natural mechanism that lowers body temperature. "Naturally, when the body falls asleep, it begins to reduce its temperature, reaching its lowest point around 4:00 a.m. When the body returns to its normal temperature, we wake up," explains Professor Haim. "After exposure to red light, the body continued to behave naturally, but exposure to blue light caused the body to maintain its normal temperature throughout the night, further evidence of damage to our natural biological clock." The most significant finding in terms of sleep disruption was that exposure to blue light drastically disrupts sleep continuity. While after exposure to red light (at both intensities) people woke up an average of 4.5 times (unnoticed awakenings), after exposure to weak blue light they recorded 6.7 awakenings, which rose to 7.6 awakenings after exposure to strong blue light. It is therefore not surprising that participants reported in questionnaires that they felt more tired and in a worse mood after exposure to blue light. “Exposure to screens during the day in general, and at night in particular, is an integral part of our technologically advanced world and will only become more intense in the future. However, our study shows that it's not the screens themselves that harm our biological clock and, therefore, our sleep, but the short-wavelength blue light they emit.

Fortunately, there are several apps available that filter out the problematic blue light in the spectrum and replace it with dim light, thereby reducing the damage to melatonin suppression.”