Restoring Slow Wave Sleep Shown to Enhance Health and Increase Lifespan
By Jim English
If you have trouble falling asleep, wake up frequently in the middle of the night, or get out of bed in the morning feeling drained and exhausted, you are not alone. A recent survey indicates that as many as 40 million Americans suffer from disrupted and inadequate sleep.1
Impaired sleep exerts a heavy toll on emotional and physical health, degrading mental abilities, productivity and performance, while increasing stress, irritability, depression and daytime drowsiness. According to the US National Sleep Foundation, sleep deprivation also reduces concentration, alertness, and reflexes, making sleep-deprived individuals more prone to falls and accident-induced injury.2
Sleep loss is now linked to a number of serious health conditions, including obesity, heart disease and Type 2 diabetes. Significantly, new research suggests that inadequate and/or fragmented sleep is linked to premature deaths in older adults.
Reliance on sleeping aids continues to grow as restless insomniacs seek relief for a wide range of lifestyle-related sleep disorders. Modern pharmaceuticals are widely prescribed for relief for insomnia, sleep apnea and restless leg syndrome, while natural supplements such as melatonin and 5-HTP are commonly used to treat jet lag and aid shift workers (policeofficers, nurses, etc.) who must cope with constantly changing sleep schedules.
SleepCycle®
SleepCycle® is an advanced, all-natural supplement that offers a comprehensive approach to restoring healthy sleep patterns. Unlike sleep aids designed to simply knock people out, SleepCycle addresses each stage of human sleep with targeted nutrients and plant compounds that have been shown to gently enhance the quality and duration of deep, restorative sleep to aid the body in recovering from daily physical and mental stresses.
To Sleep, Perchance to Dream…
Humans need little beyond food, water, air and sleep to survive. Of these, sleep remains the most mysterious and elusive requirement. While researchers do not yet fully understand the nature of sleep, what has been established is that regular bodily rest is absolutely critical to physical and mental health.
Human sleep is controlled by an internal biological “body clock” that is synchronized to a normal, 24-hour day/ night circadian cycle (circadian is Latin for “around a day”). Circadian cycles, or rhythms, control a wide range of physiological and behavioral processes, including brain wave activity, alertness, body temperature, hormone production and cell regeneration.
In humans and other mammals, circadian sleep cycles are controlled by a small organ called the suprachiasmatic nucleus (SCN). Located in the hypothalamus at base of the brain, the SCN synchronizes internal circadian rhythms with the external world in response to changing light levels (i.e., sunrise, sunset). When light levels are highest, receptors in the eye stimulate the SCN to inhibit the release of the master sleep hormone, melatonin, from the pineal gland. As light levels drop with the approach of night, impulses from the SCN cease, allowing melatonin to be released to initiate sleep.
When it works correctly, the SCN maintains precise control over sleep patterns by constantly monitoring changes in light levels and sending out the appropriate signals to either keep us alert or trigger sleep. Unfortunately, this mechanism is sensitive to disruption and its timing can be thrown off, resulting in disruption of sleep cycles. A prime example of this is jet lag, which occurs when external light cues are altered after crossing multiple time zones.
Symptoms of jet lag, such as fatigue, sleep disruption, confusion, anxiety, depression and constipation, are also experienced by older adults with disturbed sleep patterns. Researchers now believe that the age-related disruption of human circadian sleep patterns is caused by alterations in the body’s normal timekeeping system.
Phases of Human Sleep
Human sleep occurs in two distinct phases: REM (Rapid Eye Movement) and non-REM sleep. NonREM sleep initiates each sleep cycle and consists of four stages:
* Stage 1 - Light Sleep: The drowsy transition between wakefulness and sleep is characterized by slowly rolling eye movements and the ability to awaken easily.
* Stage 2 - Decreased Awareness: Sensory awareness is reduced as the brain disengages from the external environment. Stage 2 is marked by slower brain waves, interspersed with rapid waves.
* Stage 3 & 4 - Slow Wave Sleep: The final stages of nonREM sleep, Slow Wave or Deep sleep, are marked by very low heart and respiratory rate, extremely slow brain waves and a complete lack of eye movement or muscle activity. Arousal from slow wave sleep is difficult and can result in disorientation and confusion. Slow wave sleep allows the body to direct its resources to regenerate tissues, build bones and muscle, recharge energy stores and strengthen the immune system.
REM Sleep
REM sleep is a deep sleep phase marked by periods of rapid eye movement and intense dreaming, possibly related to the process “memory consolidation” wherein the brain sorts through the previous day’s experiences to form long-term memories. As the body cycles between nonREM and REM sleep throughout the night, each recurring REM cycle last longer than the previous one, with the final REM phase lasting up to an hour.
Humans spend almost 50 percent of their total sleep in stage 2 sleep, about 20 percent in REM sleep, and the remaining 30 percent in the other stages. Infants, by contrast, spend about half of their total sleep time deep in REM sleep.
Age-Related Sleep Problems
One of the biggest problems facing adults is the inability to achieve a deep, restful sleep, and by age 64 about half of all adults report some form of sleeping disorder.3 Age-related sleep disorders have been linked to biochemical changes in the body’s internal clock that alter the normal response to external light cues (i.e. sunset, sunrise). This results in older people going to sleep earlier in the evening and waking up earlier in the morning. Older sleepers also tend to wake up more frequently during the night, resulting in fragmented sleep.
Sleep Loss in Middle Age
In the first study of its kind, sleep researchers at the University of Pittsburgh have shown that altered sleep patterns actually begin in what many consider to be their most productive years – middle age. This finding surfaced as researchers tracked the sleeping patterns of 110 healthy volunteers, aged 20 to 59 years. They found that the quality and duration of sleep changed dramatically between the mid-20s and the mid-50s, with subjects going to bed and waking up earlier. The subjects also slept less, woke up more often during the night, and experienced fewer stages of deep sleep.4
According to study author, Dr. Julie Carrier, “Middle age is a turning point for sleep. Some sleep patterns have already changed significantly by the time an average adult reaches age 30.” Dr. Carrier observed that these changes are most likely tied to gradual age-related changes in features of the biological clock. “We need to learn where the system breaks down. If we are able to find out what is causing the biological clock to change with age, we may be able to discover ways to overcome these changes and help get these people back on track.”
Progressive Loss of Melatonin
As sleep scientists continue to investigate the body’s biological clock, existing research has already shown how disrupted sleep patterns are linked to significant age-related alterations in hormone production. One well-established example is the age-related decline in melatonin, the principal hormone produced by the pineal gland (Fig. 1). Melatonin is a vital neurohormone involved in regulating the neuroendocrine system and controlling essential functions such as metabolism, sex drive, appetite, and sleep. Melatonin also exerts powerful antioxidant activity and plays a key role in the immune system by preventing the proliferation of cancer cells.
As mentioned earlier, melatonin production and release is controlled by the body’s “biological clock” (suprachiasmatic nucleus) in response to changes in daily light/dark cycles. Melatonin levels are known to drop significantly after childhood and serve as one of the most dramatic markers of biological aging known. By the age of 60, nighttime melatonin production practically ceases, and by age 80 melatonin plasma levels are barely detectable.
Obesity Linked to Lack of Sleep
Sleep scientists have identified additional links between disrupted sleep cycles and age-related alterations in hormonal levels. In one study, researchers from the Stan-ford University School of Medicine have shown that getting less than 8 hours of sleep leads to increased levels of ghrelin, a hormone produced by the stomach that makes people hungry, slows metabolism and decreases the body's ability to burn fat.5 Ghrelin levels in the blood spike before meals and drop afterward. People given ghrelin injections become voraciously hungry, consuming up to 30 percent more calories than they normally would.6
The Stanford researchers also discovered that inadequate sleep results in lower levels of another appetite hormone, leptin. In contrast to ghrelin, lower levels of leptin signal the body that it is starving, further increasing appetite and the drive to consume extra calories.
The Stanford study revealed a 14.9 percent increase in ghrelin levels, and 15.5 percent decrease in leptin levels in people who consistently slept for only five hours, compared with those who slept for eight. These findings are supported by previous studies that show that people who get less than four hours of sleep each night are 73 percent more likely to be obese than normal sleepers.
Drop in Growth Hormone Linked to Slow Wave Sleep
In related news, researchers from the University of Chicago School of Medicine have associated sleep loss with the age-related drop in human growth hormone (GH). Growth hormone is normally released during the most restful phase of slow wave sleep (SWS). Growth hormone plays a vital role in human health, stimulating bone growth, immune function, amino acid uptake, protein synthesis, and muscle glucose uptake. Growth hormone also induces the burning of fat from adipose tissues and plays a key role in maintaining cardiovascular health.
Reduction of growth hormone in aging humans is associated with immune system malfunctions, increased body fat deposits, a loss of muscle tone and overall physical strength, thinning of skin, and diminished sexual drive.
When the Chicago researchers monitored the sleep patterns of 149 healthy men, aged 16 to 83 years, over a period of 14 years they discovered that the total amount of time spent in slow wave sleep (SWS) dropped from 19% of total sleep in early adulthood to only 3% by midlife. This decline in restorative slow wave sleep was matched by major declines in the secretion of human growth hormone.7
Elevated Cortisol and REM
In the same study the Chicago researchers noted a significant increase in evening levels of cortisol in subjects 50 years and older. These elevated cortisol levels were associated with increased sleep fragmentation and further declines in REM sleep. Cortisol, the body’s principal anti-inflammatory hormone, is typically released by the adrenal glands in response to stress. While some cortisol is necessary, chronically elevated cortisol levels (hypercortisolemia) contribute to obesity, hypertension, reduced glucose tolerance (a contributing factor in developing diabetes), loss of bone density, decreased muscle mass and increased neuronal death of brain cells.
Sleepless Rats Reveal Problem in Biological Clock
Two recent animal studies seem to confirm that problems within the body’s cellular clock serve as a crucial source of age-related sleep problems while suggesting that the clock can be “reset” to more youthful levels – at least in aged rats.
In the first study, researchers at Washington University in St. Louis examined cells from the suprachiasmatic nucleus (SCN) that are responsible for generating circadian rhythms. They discovered that the electrical activity of these “clock cells” in older rats was irregular when compared with the activity of timing cells in young and middle-aged animals. According to Erik Herzog, Ph.D., assistant professor of biology at Washington University, "In the case of the aged rats, many of them showed fragmented behavioral rhythms. The cells in the older rats were still rhythmic, but showed bouts of activity when they normally would have rested, and inactivity when the young animals were active. So, the rats, like elderly humans, took naps when they would have normally been active. Remarkably, the cells in their biological clock reflected this behavior.8
Research Links Healthy Biological Clock to Longevity
In a related study supported by the National Institute on Aging in the US and the Natural Sciences and Engineering Research Council in Canada, researchers transplanted fresh brain cells harvested from the suprachiasmatic nucleus of young hamsters into the biological clocks of aging hamsters. Normally, once a hamster’s biological clock has begun to deteriorate, death occurs within three months. However, after the researchers transplanted the new “clock” into hamsters whose own clocks had begun to deteriorate, the animals lived an average of four months longer than hamsters without the transplant – equivalent to increasing their lifespan by an astonishing 20 percent.
According to psychologist Martin Ralph of the University of Toronto, other therapies might achieve similar results. "If the function of the clock can be mimicked by a structured lifestyle, such as more light during the day and darkness at night, then this will work in the same direction as the transplant works in hamsters.”9
Poor Sleep Linked to Early Death in Older Adults
Sleep disturbances have been shown to double the risk of death for healthy older adults compared to more restful seniors, according to new research. Lying awake for 30 minutes or longer and spending a smaller percentage of the night asleep boost the risk of death among older adults, according to Mary Amanda Dew, Ph.D., and colleagues at the University of Pittsburgh School of Medicine.
Older adults who sleep poorly tend to have a diminished quality of life, but the study by Dew and colleagues suggests that sleep disturbances can have a much more serious effect on health.
"Interventions that optimize or protect sleep initiation and sleep quality in old age might not only add quality of life but prolong life as well,” Dew says.
In eight different studies between 1981 and 1997, the researchers used EEG monitors to observe sleep patterns in 185 healthy adults 60 to 90 years old. Dew and colleagues then collected follow-up information to find which study participants had died by the year 2001.
The 66 adults who had died were more likely in the earlier sleep studies to lie awake for long periods, to sleep less "efficiently" through the night and to have abnormally high or low amounts of REM sleep, compared to study participants who were still living at the time of follow-up.
The link between poor sleep and earlier death remains significant, even after adjusting for the influence of age, gender and existing health problems, the researchers note.10
SleepCycle® for a Deeper Night’s Sleep
Though people frequently tend to focus on falling asleep quickly, a far better indicator sleep quality is the ability to wake up feeling refreshed, energized and restored the following day. Consequently, SleepCycle is not intended to act like a fast-acting sleeping pill that knocks people out quickly. Instead, SleepCycle works by gently promoting a state of calm as it initiates the natural process of falling asleep. Over time, SleepCycle conditions and improves the overall quality of sleep by gradually extending the duration of deep, Slow Wave Sleep (SWS) and shortening the length of time it takes to fall into a restful slumber.
SleepCycle achieves this by combining traditional herbal extracts with state-of-the-art modern nutrients to deliver a unique, safe and highly effective natural sleep aid.
SleepCycle begins with two nutritional compounds, melatonin and 5-HTP, that have been shown to aid in resynchronizing the body’s biological clock to promote healthier sleep rhythms. SleepCycle also contains a well-known combination of natural plant extracts that have been used for centuries to promote deep, restful sleep, including Hops, Lemon balm, Passionflower, Valerian root, Angelica, Jujube, and Polygala. Additionally, SleepCycle contains L-Theanine, an amino acid derived from green tea prized for its ability to promote calm and relax the mind.
Finally, SleepCycle contains a new, clinically researched herbal ingredient, Wulinshen, that is derived from the traditional herb, Xylaria Nigripes by way of a proprietary pharmaceutical extraction and formulation process. This proprietary compound, found only in SleepCycle, provides critical and often depleted nutrients required by the brain to assist biochemical processes involved in promoting restful, deep sleep. Wulinshen contains significant amounts of glutamic acid, gamma-aminobutyric acid (GABA) and glutamate decarboxylase. GABA's main function is to inhibit excitatory neuro-activities by exerting a tranquilizing effect on the central nervous system. Glutamate decarboxylase (GAD) supports the synthesis of GABA, while glutamic acid assists the uptake of GABA to specific brain cell receptors.
Summary
SleepCycle is an advanced, all-natural supplement that offers a comprehensive approach to restoring healthy sleep patterns. Unlike conventional sleeping aids that are designed to just put people to sleep quickly, SleepCycle targets each phase of human sleep with nutrients and plant compounds that have been shown to gently enhance the quality and duration of deep, restorative sleep, aiding the body in recovering from daily physical and mental stresses..
References
1. NIH Office of Communications and Public Liaison, National Institute of Neurological Disorders and Stroke
2. http://www.sleepfoundation.org
3. E. J. W. Van Someren. “Circadian and sleep disturbances in the elderly.” Experimental Gerontology, Volume 35, Issues 9-10, December 2000, Pages 1229-1237.
4. University Of Pittsburgh Medical Center. “Deterioration Of Sleep During Middle Age Related To Changes In The Biological Clock.” ScienceDaily 25 June 1998.
5. Stanford University Medical Center. “Stanford Study Links Obesity To Hormonal Changes From Lack Of Sleep.” ScienceDaily 9 December 2004.
6. Plasma ghrelin levels after diet-induced weight loss or gastric bypass surgery. N Engl J Med. 2002 May 23;346(21):1623-30.
7. Age-Related Changes in Slow Wave Sleep and REM Sleep and Relationship With Growth Hormone and Cortisol Levels in Healthy Men Eve Van Cauter, PhD; Rachel Leproult, MS; Laurence Plat, MD JAMA. 2000;284:861-868.
8. Washington University In St. Louis (2001, August 14). Sleepless Aged Rats Show Biological Clock Problems. ScienceDaily.
9. University Of Toronto (1999, March 29). Research Links Healthy Biological Clock To Longevity. ScienceDaily.
10. Center For The Advancement Of Health, 2003, February 4.