Sleep owns a vital mark for the healthy functioning of a human body framework. Its deprivation is an epidemic brewing globally and is a question of interest in this era. Sleep quality has declined over the period of years. May it be the consequence of health issues or lifestyle changes. Adults are more susceptible to sleep deprivation and it is hard to make out whether it is a consequence of aging or a health issue.
The American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) suggest an average sleep of 7 or more hours for an adult to maintain optimal health,1
Sleep deprivation results in impaired memory and attention. The long-term deprivation can call for serious neurological dysfunction and even prove fatal.
Sleep Quality Index
“Sleep quality index” is the self-assessment of quality of sleep, based on the questionnaire of seven sleep parameters including subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. The sum of scores for these seven components lies in the range of 0 to 21. The lowest score closest to 0 is considered as best score in terms of healthy sleep. Whereas the highest score is related to potential sleep disorders including sleep apnea, insomnia, and Narcolepsy (daytime drowsiness).2
Dreaming, an important aspect of Sleep
NREM (Non-REM) and REM (rapid eye movement) are 2 stages of sleep. Where NREM is the initial stage of sleep and REM sleep is the dreaming phase of sleep and occurs 90 minutes after you sleep. It involves conversion from shallow to a deep sleep where the brain encounters realistic dreams. It is followed by heightened brain activity, heart rate, and breathing. Lack of REM sleep can lead to reduced memory, reduced coping skills, migraine, and Obesity.3,4,5
It is reported that it’s the lack of REM sleep and dreaming which are responsible for the declining sleep quality index. 6
Additionally, if you can retain realistic memories of last night’s dreams, then you’re getting some good quality sleep.
Benefits of a good sleep
- Healthy sleep is essential for the systematic functioning of the brain, mood, mental health, cardiovascular, metabolic health, and immune system.7
- Regulates consciousness and reduces the risk of road accidents and injuries.
- Less fatigue and increased output at the workplace.
In a recent study, on Japanese men, it was recorded that a one-hour of increased sleep in a week resulted in increased hourly labor income and hourly wage by up to 6–8%.8
- Reduces risk of obesity, diabetes, hypertension, and depression.
- Most importantly maintains healthy relationships and keeps you socially alive.9
How poor sleep affects health?
1. Chronic insufficient sleep is associated with several health conditions including Cardiovascular disease, Diabetes, Obesity, and Cancer.10
2. Narcolepsy: It is a chronic neurological disorder affecting the sleep cycle in the brain. 1 in 2,000 patients is affected by it but it can potentially impair the quality of life.11
3. Creates Hormonal imbalance
Sleep deprivation also markedly decreases glucose tolerance and increases insulin resistance. 15
Growth Hormone, responsible for stimulating growth is also suppressed due to sleep deprivation and potentially modulates pubertal development and growth. 16
4. Exercise/Performance: In a study, it was observed that healthy sleep influences the next day's exercise rather than exercise influencing sleep. Therefore, improved sleep can encourage physical activity regimens of any form.
5. Brain functioning
The American sleep association reviews sleep deprivation's effect on the Brain in 5 Stages. 17
- Stage 1 is 24 hours without sleep and its effect is mild.
- Stage 2 is 36 hours without sleep and the brain’s ability to learn new things, memorize, react, and decide gets weakened in this stage.
- Stage 3 is 48 hours without sleep and the brain experiences “Microsleeps” in this stage. Microsleeps are the occurrence of falling asleep unintentionally from anywhere between a fraction of a second to 15 seconds.
- Stage 4 is 72 hours without sleep and the brain experiences intense anxiety, and hallucinations during this stage.
- Stage 5 is 96 hours without sleep and the brain experiences intense feelings of delusion also known as “Sleep Psychosis,” in which the brain is unable to interpret reality.
Sleep deprivation after this stage is very dangerous and can be fatal.
Strategies to improve the quality of sleep?
1. Exercise in routine is encouraged for its positive effect on sleep.
In a study, it was reported that high-intensity exercise performed two hours before bedtime does not influence night sleep. Whereas, late-evening intense exercises performed one hour before bedtime may delay the sleep process.18
Whereas low-intensity exercises in routine are reported to induce positive changes in sleep behavior.19
2. Reduced caffeine consumption at night
Caffeine is looked upon as energy, mental alertness, and a performance-enhancing supplement.
Caffeine consumption 6 hours before sleep is reported to have disruptive effects on sleep. 20 Since it circulates in the blood for 6-8 hours after its consumption. Therefore caffeine consumption after 3-4 pm is not recommended for healthy sleep.
3. Exposure to light
Scientists strongly recommend daylight for better sleep.
Exposure to daylight has been proven to increase evening fatigue, and sleep duration, hence improving overall sleep quality. 21
On the contrary, artificial light or light from LED screens is reported to disrupt the sleep cycle by suppressing melatonin secretion (a hormone that promotes sleep). 22
In another finding, it was reported that reading an e-book took longer to fall asleep than when reading a printed book since light emitted by electronic devices suppresses melatonin production and disturbs the biological sleep cycle. 23
Instead, wearing blue-light filtering glasses creates a form of physiologic darkness, improving both sleep quantity and quality. This cost-effective sleep intervention can improve work engagement task performance with less strain on eye muscles. 24
4. Use of Smartphones
Excess smartphone use may also delay sleep onset.
In a recent study conducted on 1925 students (aged 17–23yrs) in Saudi Arabia, it was found that using the mobile screen for more than 8 hours out of 24 hours or using the mobile for at least 30 minutes before sleeping after the lights have been turned off, disrupt sleep quality.
Besides, mobile-related sleep risk factors (MRSRF) were highly prevalent amongst mobile users.25
However, the effectiveness of the Night Shift feature available in the iPhone on the biological sleep cycle is still unknown.
A recent study on the usage of the night shift feature of the iPhone evaluated that it does not help out in improving sleep.32
5. Sticking to a routine
Regularizing a sleeping pattern can help improve sleep quality. Fixing your time to sleep and wake up can help with the same.
6. Avoiding alcohol
Alcohol is considered a sedative, induces sleep, and relieves insomnia.
The older age group is more susceptible to insomnia and unfortunately directly related to increased alcohol intake. But heavy consumption of alcohol for a prolonged period leads to disturbed sleep cycles and other sleep disorders.
Therefore, excess alcohol consumption particularly at night is highly discouraged.26
7. Early dinner
Late-night eating or snacking is associated with decreasing sleep quality index.
In one study, consuming carbohydrate-rich food 4 hours before sleeping, increased sleep quality.27
In another study, intake of healthy food items was associated with better sleep quality, while a higher intake of processed and sugar-rich foods was associated with a disturbed sleep cycle.28
8. Supplements for improving the quality of sleep
- Melatonin dietary supplement is safer for Short-term use to improve the sleep quality index of individuals with respiratory diseases, metabolic disorders, and primary sleep disorders.29
- Besides, including Amino acids (Glycine, L- theanine), Vitamin D and Magnesium rich diet or as a supplement will also promote sleep. 30
- Food items rich in Glycine includes pulses, fish, dairy, and meat.
- Food items rich in L-theanine includes green tea, black tea, white tea, oolong tea, and mushrooms.
- Food items rich in Vitamin D includes Fish, egg yolks, red meat, liver, mushrooms, and fortified foods (cow’s milk, soy milk, cereals, and oatmeal).
- Valerian root supplement is also effective in treating insomnia, stress, anxiety, and related sleep disorders.
9. Maintaining an ambiance in the room
Minimalizing the use of extra lights, cutting noise, and maintaining an optimum temperature in the room and comfortable bedding can potentially improve the quality of sleep.
10. Relaxation techniques
Relaxation techniques such as Massaging, Meditating, Reading Books, Enjoying Soft Music, and Aromatherapy can promote quality of sleep.
11. Shower before sleep
A relaxing full bath or even washing your feet before going to bed can also effectively promote the quality of sleep.
12. Avoiding drinking water before bed
Nocturia is the medical term used for frequent urination at night. It is one of the major causes of sleep disturbance at night.
Drinking before sleeping will cause the sensation of bladder fullness that cause awakening and ultimately a conscious decision to get out of bed to go to the bathroom. 31
Therefore avoiding drinking water 1-2 hours before bedtime can improve sleep quality index.