Our guide, on everything you need to know about sleep
Far from a luxury sleep is known to be essential, required for health and optimal functioning.
This overview of sleep is designed to provide you with a guide to the process of sleep, and the effects that deficits can have on wellbeing, and practical tips on how to improve the quality of sleep.
Looking at solutions people find helpful to manage these issues, bearing in mind what works for one person may not benefit another.
Some estimates suggest sleep problems constitute a global pandemic that threatens health and quality of life for up to 45% of the world population.
Most importantly to remember, in order to sleep well, we need to work with the body and not against it
Sleep Architecture - The Stages of your sleep
Once the eyes are closed and the brain no longer receives visual inputs, brain waves settle into a steady and rhythmic pattern of about 10 cycles per second. This is the alpha-wave pattern, characteristic of calm, relaxed wakefulness. Some brain centres and pathways stimulate the entire brain to wakefulness; others promote falling asleep. One brain chemical, hypocretin (also called orexin), seems to play an important role in regulating when the flip between states occurs and managing the new state. Unless something disturbs the process, generally a smooth transition takes place into the three stages of quiet sleep.
- In making the transition from wakefulness into light sleep, about five minutes is spent in stage 1 sleep.
- Predominant brain waves slow to four to seven cycles per second, a pattern called theta waves.
- Body temperature begins to drop, muscles relax, and eyes often move slowly from side to side.
- People in stage 1 sleep lose awareness of their surroundings, but they are easily jarred awake.
Stage 2 (light sleep)
- This first stage of true sleep lasts 10 to 25 minutes. The eyes are still, and heart rate and breathing are slower than when awake and the brain’s electrical activity becomes more irregular with two types of patterns emerging which are unique to this stage.
- Sleep spindles are brief bursts of activity in which brain waves speed up for roughly half a second or longer between larger, slower waves.
- This is thought to reflect the process of memory consolidation (which involves organizing memories for long-term storage). Another pattern of brain wave also emerges during this phase, known as K-complexes that are thought to represent a sort of built-in vigilance system that enables awakening if necessary. K-complexes can also be provoked by certain sounds or other external or internal stimuli. About half the night in stage 2 sleep.
Stage 3 (deep sleep, or slow-wave sleep)
- Eventually, large, slow brain waves called delta waves become a major feature as one enters deep sleep. Breathing becomes more regular. Blood pressure falls, and the pulse slows to about 20% to 30% below the waking rate.
- The brain is less responsive to external stimuli, making it difficult to wake the sleeper. Deep sleep seems to be a time for the body to renew and repair itself. Blood flow is directed less toward the brain, which cools measurably.
- At the beginning of this stage, the pituitary gland releases a pulse of growth hormone that stimulates tissue growth and muscle repair.
- Researchers have also detected increased blood levels of substances that activate the immune system, raising the possibility that deep sleep helps the body defend itself against infection.
- Normally, young people spend about 20% of their sleep time in stretches of deep sleep lasting up to half an hour, but deep sleep is vastly reduced in most people over age 65.
Dreaming (REM) sleep
- REM sleep occurs about three to five times a night, or about every 90 minutes.
- The first such episode usually lasts for only a few minutes, but REM time increases progressively over the course of the night.
- The sympathetic nervous system, which creates the fight-or-flight response, is twice as active during this time.
- Despite all this activity, the body hardly moves, except for intermittent twitches; muscles not needed for breathing or eye movement are quiet.
- Just as deep sleep restores the body, it is thought REM sleep restores the mind, perhaps in part by helping clear out irrelevant information.
- The final period of REM sleep may last a half-hour. During this time, the body temperature increases as does blood pressure, and heart and respiratory rates speed up to reach daytime levels.
- Deprivation of REM sleep followed by a subsequent night of undisturbed sleep, causes this stage to be entered earlier and a higher proportion of time spent in it—a phenomenon called REM rebound.
The Circadian Clock
This internal clock, which gradually becomes established during the first months of life, controls the daily ups and downs of biological patterns, including body temperature, blood pressure, and the release of hormones. Circadian rhythms make people’s desire for sleep strongest between midnight and dawn, and to a lesser extent in mid-afternoon.
A structure in the brain called the suprachiasmatic nucleus is the location of the internal clock. This cluster of cells is part of the hypothalamus, the brain center that regulates appetite and other biological states. Although the clock is largely self-regulating, its location allows it to respond to several types of external cues to keep it set at 24 hours called “zeitgebers,” a German word meaning “time givers.”
- Exposure to light at the right time helps keep the circadian clock on the correct time schedule. However, exposure at the wrong time can shift sleep and wakefulness to undesired times. The circadian rhythm disturbances and sleep problems that affect up to 90% of blind people demonstrate the importance of light to sleep/wake patterns.
- The part that time plays within everyday life, dictating schedules and activities creates demands that the body remain alert for certain tasks and events, inducing cognitive pressure to stay on schedule.
- Cells in the suprachiasmatic nucleus contain receptors for melatonin, a hormone produced in a predictable daily rhythm by the pineal gland, which is located deep in the brain. Levels of melatonin begin climbing after dark and ebb after dawn. The hormone induces drowsiness, and is believe its daily light-sensitive cycles help keep the sleep/wake cycle on track.
Sleep journey throughout your life
Many factors can affect how a person sleeps. Aging is the most important influence on basic sleep rhythms—from age 20 on, it takes progressively longer to fall asleep. Older people tend to sleep less each night, stages 1 and 2 sleep increase, deep sleep and REM decrease, with more frequent awakenings during the night.
A newborn may sleep eight times a day, accumulating 17 hours of sleep and spending about half of it in frequent periods of REM sleep, usually occurring less than an hour apart. At about the age of 4 weeks, a newborn’s sleep periods get longer. By 6 months, infants spend longer and more regular periods in non-REM sleep; most begin sleeping through the night and taking naps in the morning and afternoon. During the preschool years, daytime naps gradually shorten, until by age 6 most children are awake all day and sleep for about 10 hours a night. Between age 7 and puberty, nocturnal melatonin production is at its lifetime peak, and sleep at this age is deep and restorative.
Teenagers still need about eight to 10 hours of sleep each night. But starting around adolescence, many sleep less than they need. Many factors contribute to the problem, such as drinking caffeinated beverages or staying up too late doing homework or texting friends. But teens’ natural sleep/wake cycles also begin to shift up to two hours later once they reach puberty. That means they may not be sleepy until well after their bedtime and may have difficulty waking up early enough to get to school on time.
During young adulthood, sleep patterns usually seem stable but are slowly evolving. Between age 20 and age 30, the amount of deep sleep drops by about half, and night-time awakenings double. By age 40, deep sleep is markedly reduced.
Women’s reproductive cycles can greatly influence sleep. During the first trimester of pregnancy, many women are sleepy all the time and may take an extra two hours a night if their schedules permit. As pregnancy continues, hormonal and anatomical changes make sound, restful sleeping a challenge, so less of a woman’s time in bed is actually spent sleeping. As a result, fatigue increases. After giving birth, women are often exhausted. Not only are they at the mercy of their newborn’s erratic sleep schedule, but breastfeeding also promotes sleepiness.
Women who aren’t pregnant may notice that their sleep habits shift throughout the month. During the second half of the menstrual cycle, progesterone levels rise, which tends to make women more drowsy than when levels are lower during the first half of the cycle. When both progesterone and estrogen levels fall a few days prior to menstruation, many women have trouble sleeping—one of the main symptoms of premenstrual syndrome, or PMS.
As men and women enter middle age, deep sleep continues to diminish. Night-time awakenings become more frequent and last longer. Waking after about three hours of sleep is particularly common. During menopause, many women experience hot flashes that can interrupt sleep. Obese people are more prone to nocturnal breathing problems, which often start during middle age. Men and women who are physically fit sleep more soundly as they grow older, compared with their sedentary peers.
In older adults, REM sleep decreases a small amount, but still hovers around 20% of total sleep time. Other changes are more pronounced. Deep sleep accounts for less than 10% of sleep time, and in some people it is completely absent. Falling asleep takes longer, and the shallow quality of sleep results in dozens of awakenings during the night. At any age, most adults need seven or more hours of sleep to function at their best. Because of the frequent fragmentation of sleep, it can take longer in bed to get the same amount of sleep. If older people are unable to get all the required sleep at night, they often supplement night-time sleep with daytime naps. This can be a successful strategy for accumulating sufficient total sleep over a 24-hour period. However, it’s best to take one midday nap, rather than several brief ones scattered throughout the day and evening.
partial sleep deficit
Partial sleep deficit occurs when sleep duration and quality is less than optimally needed and leads over a period of time to sleep debt. After a single night of short sleep, most people function at or near their normal level usually getting through the day without others noticing that anything is amiss. After two or more nights of lack of sleep, people usually show signs of irritability and sleepiness. Work performance begins to suffer—particularly on complicated tasks— and people are more likely to complain of headaches, memory lapses, and sluggish reaction time. In addition, people face a far higher risk of falling asleep on the job or while driving.
Long-term partial sleep deprivation occurs when someone gets less than the optimal amount of sleep for long periods on end—a common scenario for insomniacs and people with sleep disorders. The health consequences of such a situation can include higher blood pressure and levels of the stress hormone cortisol, an impact on immune function and signs of insulin resistance—a condition that is the precursor of type 2 diabetes.
A growing number of studies have linked long-term sleep deficits with significant health problems including diabetes, and elevated risk factors for heart disease, including higher cholesterol levels, higher triglyceride levels, and higher blood pressure. People who don’t get sufficient sleep tend to have higher blood levels of stress hormones and substances associated with inflammation, a key player in cardiovascular disease. There are also concerns that certain mental health conditions can be exacerbated or complicated by sleep deficit. Finally, it is thought continued lack of sleep can be detrimental to the immune function and contribute to weight gain.
Practical tips for better sleep
Getting enough sleep is just as important as other vital elements of good health, such as eating a healthy diet, getting regular exercise, and practicing good dental hygiene. In short, good sleep quality is not a luxury but a basic component of a healthy lifestyle. But getting adequate sleep requires time and discipline. Mentally block off certain hours for sleep and then follow through on your intention, avoid building up a sleep debt, and take steps to set up an ideal sleep environment. Following are some ways to improve your sleep. These good habits are known as “sleep hygiene,” because they represent scientific thinking about maintaining healthy sleep patterns.
Food & Drinking
A sleep-friendly bedroom can make it easier to fall and stay asleep, so take time to address issues which act as distractions and that affect or prevent falling and staying asleep in bed.
A quiet bedroom is especially important for older adults, who spend less time in deep sleep. As a result, they are more easily awakened by noises. Here are some ways to reduce or disguise noises that can interfere with sleep: Decorate with heavy curtains and rugs, which absorb sounds: Install double glazing; Use earplugs; consider relaxing background sounds that help induce sleep.
Bright light at night can suppress the body’s production of melatonin and make it harder to sleep. Keep pre-bedtime light intake down with these steps: Avoid watching television or using a computer after 9 p.m; Don’t read from a backlit electronic device (such as an iPad) at night. Replace bright lights with lower-wattage bulbs, or install dimmer switches that allow the lights to be kept low at night. Bright bathroom lights can be an issue, especially since most people use the bathroom immediately before retiring (and often in the middle of the night). In the latter situation consider using night-lights to light the way to, in and from the bathroom to ensure personal safety.
A bedroom that’s too hot or too cold may interfere with sleep. Most people sleep best in a slightly cool room (around 65° F). Replace the mattress and pillows if they’re worn or uncomfortable. If aching joints are a problem seek professional advice. Some people say they are more comfortable sleeping on “memory foam” mattresses and pillows.
Worrying about a problem or a long to-do list can be a recipe for insomnia. Well before bedtime, try writing down worries and make a list of tasks to remember. This “worry journal” may help move these distracting thoughts from the mind.
Closer to bedtime, try comforting rituals that may help lull you to sleep: Listen to soft, calming music; Take a warm bath.
- Do some easy stretches; Read a book or magazine by soft light.
Once in bed, relaxation techniques can help calm the body and mind. Mindfulness meditation has also been proven helpful for combatting insomnia. This type of meditation involves focusing on breathing and then bringing the mind’s attention to the present without drifting into concerns about the past or future.
A regular sleep schedule keeps the circadian sleep/ wake cycle synchronized. If falling asleep doesn’t happen within 20 to 30 minutes or wakening up again and not being able to fall back to sleep within that amount of time occurs, get out of bed and do something relaxing until sleepiness returns again. Regardless of how good or poor a night’s sleep has occurred, get out of bed at the regular time each morning to keep the circadian cycle synchronized.
If the main goal is to sleep longer at night, taking naps is not a good idea. The total daily amount of sleep needed stays constant, so naps take away from evening sleep. But if the goal is to be more alert during the day, a nap built into the daily schedule may help. Where insomnia and feeling anxious about getting enough sleep is an issue, then a short, scheduled nap may help better sleep at night by alleviating that anxiety. If possible, nap soon after lunch. People who nap later in the afternoon and/or evening tend to fall into a deeper sleep, which causes greater disruption at night. An ideal nap lasts no longer than 30 to 40 minutes, and even a 15- to 20-minute nap has significant alertness benefits. Shorten or eliminate naps that produce lingering grogginess.
A sleep diary may help uncover clues about what’s causing any sleep disturbances by uncovering trigger causes.
To keep a sleep diary, note bedtime and waking up time every day—preferably for two weeks to a month. Include entries for any medications, time and quantity of caffeine or alcohol consumption, timing and duration of exercise, use of electronic devices or TV before bedtime, and any stresses encountered during the day. All of these can affect sleep. Also note how quality of sleep, any night-time awakenings, and, if so, for how long.
Caffeine, which is found in coffee, tea, some carbonated soft drinks, and other beverages blocks adenosine, a brain chemical that helps with falling asleep. Caffeine can also interrupt sleep by increasing the need to get up to urinate at night. If sleep is continuously problematic, avoid caffeine as much as possible, since its effects can last for many hours and can help cause insomnia. Because caffeine withdrawal can cause headaches, irritability, and extreme fatigue, some people find it easier to cut back gradually rather stopping immediately. Those who can’t or don’t want to give up caffeine should avoid it after 2 p.m., or noon if they are especially caffeine-sensitive.
Alcohol depresses the nervous system, so an alcoholic drink makes some people fall asleep more quickly. But the sleep won’t necessarily be very good. Alcohol suppresses REM sleep, and the soporific effects disappear after a few hours. Drinkers have frequent awakenings and sometimes frightening dreams. Alcohol is responsible for up to 10% of chronic insomnia cases. Also, because alcohol relaxes throat muscles and interferes with brain control mechanisms, it can worsen snoring and other nocturnal breathing problems. Drinking during one of the body’s intrinsic sleepy times— mid-afternoon or at night—will make a person more drowsy than at other times of day. Even one drink can make a sleep-deprived person drowsy.
Nicotine is a potent stimulant that speeds heart rate, raises blood pressure, and stimulates fast brain-wave activity which maintains wakefulness. People who kick the habit fall asleep more quickly and wake less often during the night. Sleep disturbance and daytime fatigue may occur during the initial withdrawal from nicotine. But even during this period, many former users report improvements in sleep. Avoid smoking or using tobacco substitutes for at least one to two hours before bedtime.
Walking, jogging, swimming, or any type of exercise that gets the heart pumping faster provides three important sleep benefits: falling asleep faster, more time spent in deep sleep, less awakenings during the night. Exercise seems to be of particular benefit to older people. Even gentle exercise, such as stretching and toning, can help people sleep better, as can yoga, tai chi or pilates. Exercising outdoors in the morning is ideal, because bright, natural daylight can help reinforce natural circadian rhythms. Try to avoid exercise within two hours of bedtime because exercise is stimulating and can make it harder to fall asleep.
Eating & Drinking
Hunger can be sufficient distraction to keep people awake, so a small healthy snack, such as an apple with a slice of cheese or a few whole-wheat crackers, before bedtime should overcome this disturbance. But being overly full may be even more disrupting. Avoid eating a big meal within two to three hours of bedtime, especially any foods that contribute to acid reflux (heartburn), as lying down can provoke or worsen the problem. Avoid common culprits such as coffee, chocolate, alcohol, and fatty foods, and whilst medications that suppress stomach acid secretion can provide help for acid reflux, preventing the issue is a preferable strategy. Also, it appears sleeping on the right side aggravates heartburn, so look at lying on the left side when trying to fall asleep. Finally, drinking too much of any fluid too close to bedtime may cause night-time awakenings to use the bathroom.
Common Disorders Impacting Sleep
When one falls asleep, muscles in the airway relax, causing the airway to narrow. Snoring occurs when it narrows too much, causing turbulent airflow. The surrounding tissue vibrates, producing noise. A number of physical characteristics can contribute to long-term problems with snoring. These include;- a deviated septum (a misalignment of the bone and cartilage that separates the two sides of the nose); an elongated soft palate (the fleshy, flexible area toward the back of the roof of the mouth); a large uvula (the fleshy piece of tissue that hangs down from the soft palate; a normal-sized one clears the top of the tongue when the mouth is open); enlarged tonsils (the small masses of soft tissue on both sides of the back of the throat); enlarged adenoids (small lumps of tissue located above the tonsils); a very small jaw; excess fat in the neck area.
Sleep apnoea is a health condition in which breathing stops or becomes shallower frequently each night. In the most common form, obstructive sleep apnoea, the tongue or throat tissues block the airway. Central sleep apnoea, in which the brain does not send messages to the muscles that control breathing is less common. Untreated, sleep apnoea can have devastating consequences. The relentless daytime fatigue that often impacts upon personal and work life and lead to accidents.
Restless Legs Syndrome
Restless legs syndrome (RLS) is an exasperating condition that triggers abnormal sensations in the legs (and occasionally the arms) and an irresistible urge to move them. Moving the limbs may bring temporary relief. RLS affects about 10% of people ages 30 to 70, two-thirds of them women. As many as half of people with RLS note that they have family members with similar symptoms. Sleep deprivation is a major problem for people with RLS, as the symptoms are most prominent at night—or, in many cases, occur only at night. RLS symptoms may make it difficult to fall asleep or stay asleep, compelling the person to get in and out of bed many times. The daytime symptoms sometimes abate for a few hours, days, or even years. RLS usually worsens with age. Women may find that symptoms flare up during menstruation, pregnancy, or menopause. At least one in four pregnant women experiences restless legs. Restless legs can be brought on by alcoholism, iron-deficiency anaemia, diabetes, heart failure, or kidney failure. In some people, caffeine, stress, nicotine, fatigue, or prolonged exposure to a cold or very warm environment worsens the symptoms. Certain medications can also exacerbate RLS.
Insomnia can present as persistent trouble falling asleep, unwelcome awakenings during the night, and fitful sleep, often leading to drowsiness during the day, anxiety, irritability, forgetfulness, and lack of concentration.
Finding a remedy requires uncovering the cause and a significant number of cases stem from psychological or emotional problems such as stressful events, mild depression, or anxiety. Dependent on the individual, the main approaches to treating insomnia—behavioural therapy, natural remedies and medications can all generally work for most individuals, but many people prefer options that do not result in the side effects that can occur with the latter intervention.
Insomnia is considered transient if it lasts only a few days, short-term if it continues for a few weeks, and chronic if the problem persists. The causes of transient or short-term insomnia are usually apparent to the sufferer—the death of or separation from a loved one, nervousness about an upcoming event (such as a wedding, public speaking engagement, or move), jet lag, or discomfort from an illness or injury. Chronic insomnia may be caused by a number of medications or medical conditions. In these instances, treating the condition or changing the medication may relieve the insomnia.
One common form of persistent sleeplessness is conditioned (learned) insomnia. After a few sleepless nights, some people learn to associate the bedroom with being awake. Taking steps to compensate for sleep deprivation—napping, drinking coffee, having a nightcap, or forgoing exercise—only fuels the problem. As insomnia worsens, anxiety regarding the insomnia may also worsen, leading to a vicious cycle in which fears about sleeplessness and its consequences become the primary cause of the insomnia.
Trouble falling asleep is known as sleep-onset insomnia. Yet another type of insomnia is known as sleep-maintenance insomnia. It refers to difficulty staying asleep, and in particular, waking too early and struggling to get back to sleep. People with certain health problems, including pain, depression, and obstructive sleep apnoea, may be more prone to this type of insomnia.
Interventions for Insomnia
For chronic insomnia, the first steps are changing lifestyle and habits. The sleep hygiene techniques described earlier are a good beginning. In addition, it is important to identify potentially problematic habits that lead to sleep issues. Behavioural changes can help people with learned insomnia replace their bad habits with positive ones. Some people may start sleeping better with behaviour changes alone. But others may also need to change their thoughts and beliefs about their sleeping habits—a process referred to as cognitive restructuring. The combination of all of these techniques is known as cognitive behavioural therapy for insomnia (CBT-i).
Following are some of the techniques that are included under this broad umbrella.
People with insomnia often spend more time in bed, hoping this will lead to sleep. In reality, spending less time in bed—a technique known as sleep restriction— promotes more restful sleep and helps make the bedroom a more welcoming. As the person learns to fall asleep quickly and sleep more soundly, the time in bed is slowly extended until they obtain a full night’s sleep. Some sleep experts suggest starting with six hours at first, or whatever amount of time is typically spent asleep at night. Setting a rigid early morning waking time often works best. If the alarm is set for 7 a.m., a six-hour restriction means that no matter how sleepy the person is, they must stay awake until 1 a.m. Once sleeping well during the allotted six hours, another 15 or 30 minutes are added, then the process repeated until a healthy amount of sleep occurs.
This technique (also known as reconditioning) trains people with insomnia to associate the bedroom with sleep instead of sleeplessness and frustration. These are the rules: Use the bed only for sleeping or sex; Don’t spend time in bed not sleeping. Go to bed only when sleepy. If unable to sleep, move to another room and do something relaxing. Stay up until sleepy, then return to bed. If sleep does not follow quickly, repeat. During the reconditioning process, get up at the same time every day and do not nap, regardless of how much sleep ocurred the night before. Another related tip: Cover up the clock or face it away from view, because watching or checking a clock while trying to fall asleep can be frustrating.
For some people with insomnia, a racing or worried mind is the enemy of sleep. In others, physical tension is to blame. Techniques to manage this—such as meditation, breathing exercises, progressive muscle relaxation, and biofeedback—can be learned in behavioural therapy sessions or from books or classes. Progressive muscle relaxation involves progressively tensing and relaxing muscles. Another way to release physical tension and relax more effectively is to use biofeedback which is usually done under professional supervision.
Cognitive restructuring teaches people new ways of thinking about and then doing things. Cognitive restructuring for insomnia aims to change negative thoughts and beliefs about sleep into positive ones. People with insomnia tend to become preoccupied with sleep and apprehensive about the consequences of poor sleep. The basic tenets of this therapy include setting realistic goals and learning to let go of inaccurate thoughts that can interfere with sleep.
Prescription medications help some people with insomnia, but it’s best to use them at the lowest effective dose and for the shortest possible period of time. These drugs are most appropriate for short-term problems that disrupt sleep, such as traveling across time zones or coping with a death in the family. For longer-term insomnia, behavioural therapies should be tried first, as they are often just as effective and may have longer-lasting benefits—without the side effects of drugs.
Medications to treat insomnia include benzodiazepines, which are also used to treat anxiety; related medications known as nonbenzodiazepines, which selectively target sleep receptors in the brain; and antidepressants, which are typically prescribed in doses lower than those used to treat depression. Melatonin involved in sleep regulation is another commonly recommended medication which, although freely available as a supplement in many countries, is only available on prescription in UK.
- Generally, these products are remarkably similar with each one containing an antihistamine as its primary active ingredient. Many contain the antihistamine diphenhydramine, whilst others contain doxylamine, another antihistamine. The antihistamines found in these products have a sedating effect and are generally safe when taken as directed for brief time periods. But they can cause side effects which are generally more common in people over age 60. Alcohol heightens the effect of these medications, which can also interact adversely with some drugs.
Natural Management of sleep problems
Sleep is ubiquitous and occupies a third of our lives. Whilst we still do not fully understand the functions of sleep, the fact that we spend so much time in this vulnerable state testifies to its importance. Insomnia is a widespread health problem, with recent reports estimating that 25-30% of adults in the general population experience occasional sleep problems, while 10% suffer from sleep disturbance severe enough to meet diagnostic criteria for insomnia. As a chronic condition, insomnia entails significant personal and social costs: individuals with insomnia consistently report decreased quality of life and are at greater risk for depression. Insomnia is also associated with higher rates of absenteeism and loss of productivity, with a predominant impact on daytime functioning rather than in night-time sleep disturbances per se, resulting in fatigue and mood disturbances, difficulty handling minor irritations, reduced interest and decreased satisfaction in leisure activities and relationships. Complaints related to altered cognitive functioning are also frequent and involve memory and concentration problems, difficulty making decisions and frequent work-related mistakes.
Managing Sleep problems-naturally
A number of validated tools exist to assess the level to which problems sleeping impact upon quality of life. These include the Pittsburgh Sleep Quality Index, and the Epworth Sleepiness scale which evaluates daytime sleepiness (1,2). Other tools assess sleep hygiene by measuring behaviours and environmental variables thought to cause or lead to relatively poor sleep quality rather than measuring outcomes (3). Sleep hygiene is the practice of engaging in behaviours that facilitate sleep and avoiding those that interfere with sleep. A multi-factorial approach, is essential for successful management of insomnia, and here the basic tenet is that underlying medical or psychological conditions should be treated first. Sleep hygiene and behavioural interventions such as stimulant avoidance, exercise and relaxation are recommended first-line treatments. To avoid the side effects of prescription hypnotics, interest in the use of alternative therapies for the treatment of insomnia has recently increased exponentially. Many insomnia patients prefer natural sleep aids because they have fewer adverse effects and interactions. Here are some demonstrated in studies to be effective.
The traditional use of hops as a mild sedative stems from the observation of sleepiness and fatigue in the hop-pickers, apparently due to the transfer of hop resin from their hands to their mouths (4). The bitter resins in the hops plant, increase the activity of GABA and modulate its receptor, inducing a state of central nervous system inhibition (5). Hop is also a partial agonist to the central adenosine receptor (6,7). The German Commission E herbal monograph approved hops for the treatment of “mood disturbances, such as restlessness and anxiety, sleep disturbances” (8)
Kennedy first proposed that Melissa officinalis L. exerts its anxiolytic effect and modulates mood through the GABAergic system which controls the main inhibitory neurotransmitter (9). These findings are also consistent with the German Commission E recommendations regarding the approval of Melissa officinalis L. extract use for nervous insomnia (10).
Traditionally, chamomile preparations such as tea and essential oil aromatherapy have been used to treat insomnia and to induce calming effects and it is one of the most widely used types of CAM therapy for promoting sleep (11). In one study around 20% of participants reported having used natural sleep aids in the past 12 months, with chamomile being the most popular product (12).
Clinical trials have shown that saffron may attenuate depression and anxiety which often result in insomnia. However, saffron also induces hypnotic effects through increasing in NREM sleep duration, decreasing sleep latency and hence resulting in the reduced sleep disturbances and inducing improvements in the subjective parameters of sleepiness on rising and feeling refreshed (13).
The perennial herb valerian was recommended by the Greek physician Galen for insomnia and its reputation as a potent hypnotic/sedative continues to this day. Valerian and its constituent valerenic acid have demonstrated adenosine receptor interactions, GABA receptor agonism, and serotonin- partial agonism. Several systematic reviews and meta-analyses have been completed, most recently in 2015 (14-16). In the Bent et al. review, six studies revealed significantly improved sleep quality over placebo. In terms of safety, valerian is generally well-tolerated and, in contrast to many pharmaceutical sedative-hypnotics, does not impair psychomotor or cognitive performance (17). It is reasonable for patients to consider a trial of a high-quality supplement of valerian alone or in combination with other botanicals. If no significant improvement is noted after 6 weeks, the preparation should be stopped and other options explored.
Initially investigated because of anecdotal evidence claiming their influence on sleep, cherries have been proven through multiple studies to reduce symptoms of insomnia. Cherries, especially tart cherries (Prunus cerasus), contain high levels of anti-inflammatory substances and melatonin, both related to sleep modulation (18). Additionally, tart cherries contain tryptophan, a compound with sleep-enhancing properties (19). A pilot study on the effect of tart cherries on older adults (age ≥ 65 years) with insomnia found a statistically significant reduction in insomnia severity with cherry ingestion, as measured in minutes awake after sleep onset per 2-week mean patient diary values (20). In a separate study on twenty healthy men and women (aged 18 to 40), melatonin levels were found to be significantly elevated after the consumption of sour cherry juice concentrate, with associated significant increases in time in bed, total sleep time, and sleep efficiency (21). An additional study conducted on middle aged (35–55 years old) and older (65–85 years old) people found that the consumption of cherry cultivars yielded improvements in actual sleep time, total nocturnal activity, assumed sleep, and immobility (18). The most recent published research examined the impact of the tart cherry juice by age (age range, 20–30 years old; 35–55; and 65–85) and found that positive improvements in nocturnal rest as measured by sleep efficiency, number of awakenings, total nocturnal activity, and sleep latency were noted, particularly in those in the older age group (22).
DO YOU KNOW WHICH SUPPLEMENTS YOU SHOULD TAKE?
TAKE OUR QUICK AND FREE VITCHECK ASSESSMENT
Find out which your nutrients your body may be deficient, measuring the single or cumulative impact of life stage, lifestyle, diet and most importantly medications
Inadequate intake of magnesium has been linked to sleep disorders. Results of two studies showed that there is an association between magnesium supplementation and REM, muscle tone, and gross body movements and a positive relationship between serum magnesium levels and quiet sleep. Another study showed that the most important magnesium supplementation effect in healthy elderly subjects was short wave sleep increment (23-25).
A significant relationship has been reported between daily sleep rhythm and vitamin D. Specifically a delay in sleep phase was accompanied by the lack of dietary vitamin D. Vitamin D supplementation in a group with sleep disorders stabilised sleep after normalization of 25(OH)D levels (26). Another study showed the use of vitamin D supplements improved sleep quality, reduced sleep latency, raised sleep duration and improved subjective sleep quality in patients with sleep disorders (27).
Tryptophan and its downstream metabolite in the brain, 5-hydroxytryptophan, are precursors to the neurotransmitter serotonin and hormone melatonin. There are at least 15 serotonin receptors, many of which influence sleep-wake behaviour, and melatonin is a key modulator of circadian rhythm (28-30). The availability of ingested tryptophan in the brain is impacted significantly by dietary factors, including the presence of other amino acids, macronutrient balance, and adequacy of cofactors for enzymatic conversion such as vitamin B6 and omega-3 fatty acids (31). Therefore, tryptophan as a nutraceutical has been a target for sleep restoration, with the aim of achieving high levels of this key building block. A 2010 rigorous systematic review identified three randomized controlled trials of tryptophan that met inclusion criteria, with an average quality rating of 6.7 out of 10. Two of these were positive on several outcomes including sleep duration and quality (32-34). In the study rated highest quality (8/10), tryptophan 250 mg in either diet or supplement form performed better than placebo over 3 weeks in sleep efficiency, quality, and awakening time as measured by sleep diary (34).
Several studies have observed improved sleep quality and decreased sleep latencies following tryptophan treatment in chronic insomniacs with results consistent across different lengths of treatment period. An increase in night time sleepiness and sedative effects has also been reported in healthy individuals as early as 30 min following tryptophan administration. A benefit of the melatonin precursor, tryptophan as a sleep aid is that it does not seem to impair performance the next day suggesting support for the notion that it may improve cognition indirectly by improving sleep (35-38).
L-theanine, an amino acid commonly found in the tea plant Camellia sinensis, has become a popular option for anxiety and sleeplessness. Studies and anecdotal experience suggest that L-theanine may be useful in managing anxiety, the stimulant effects of caffeine, and sleeplessness. Several studies have shown that intake of L-theanine significantly increases α-wave activity in different areas of the cerebral cortex, leading to a relaxed state without drowsiness (39). L-theanine also increases dopamine and serotonin production, neurotransmitters associated with relaxed, positive emotional states, and decreases stress-related norepinephrine and cortisol levels, salivary IgA, and heart rate in response to an acute stressor (40). L-theanine has been shown to partially reverse caffeine-induced reductions in slow
wave sleep (41). In one study of 98 participants (42), compared to baseline measurements, actigraph watch data after 6 weeks indicated that the L-theanine cohort obtained significantly higher sleep percentage and sleep efficiency scores along with a non-significant trend for less wake time after sleep onset. L-theanine was well tolerated with no significant adverse events. In a Japanese study, 22 healthy adult men were randomized to 200 mg a day for six days or placebo (43). Measurements by wrist actigraphy showed no significant difference in total sleeping time, but the treatment group reported feeling more relaxed before bedtime, having fewer nightmares, and feeling less tired and more refreshed during the day.
Exogenous melatonin supplements have shown sleep promoting effects, decreasing sleep onset latency and increasing total sleep time. A recent systematic review of melatonin sleep studies covering 1510 patients ages 18 to 80 with primary insomnia, delayed sleep phase disorder (DSPS), blindness, and REM behavior disorder compared the effects of oral melatonin and placebo on different sleep parameters (44). Doses of melatonin ranged from 0.1 to 10 mg with two- to five-week treatment. Analysis concluded that melatonin has significant effects in treating primary insomnia, DSPS, and non-24 h sleep-wake syndrome in blind individuals.