Arianna Ferrini, PhD

Sleep really matters. Everything that has life sleeps. Sleep is as essential to our health as breathing, eating, and drinking. It allows our bodies to repair themselves and our brains to process information and consolidate memories. Extensive research has now shown that poor sleep is linked to physical issues such as a weakened immune system and mental health issues such as anxiety and depression.

Why do we sleep?

Sleep is so important that we spend one-third of our life doing it. The question of why do we sleep is an interesting one that has fascinated people for centuries. The answer, in principle, is easy. We sleep because sleep has physical and mental restorative properties. We sleep because our bodies need it to restore and repair.

Effects of Sleep Deprivation on Brain Performance and Mental Wellbeing

"It is a common experience that a problem difficult at night is resolved in the morning after the committee of sleep has worked on it." John Steinbeck

According to the National Sleep Foundation, American adults currently sleep an average of 6.9 hours per night compared with the 1940s, when the average was one hour more. In fact, in 1942, 84 percent of Americans got the recommended seven to nine hours; in 2013, that number had dropped to 59 percent 1.

These are just representative numbers from the United States, but the situation is similar worldwide. Sadly, due to our lifestyle, we are a sleep-deprived society. The National Sleep Foundation recommends 7 to 8 hours of sleep for people over the age of 64 and 7 to 9 hours for those aged 18 to 64 (kids need even more sleep). More than 50% of us sleep much less than these recommendations. Although it's unclear exactly how long humans can survive without sleep (and we really don't need to find out!), the effects of sleep deprivation start to show very quickly. After only three or four nights without sleep, you can begin to hallucinate. Prolonged sleep deprivation leads to cognitive impairments, irritability, delusions, paranoia, and psychosis 2.

There is now substantial evidence that a good night’s sleep can facilitate your cognitive performance the following day. Following sleep disruption, deficits in decision-making, emotional reactivity, attention, learning, and memorizing have all been documented 3. Just like we need to recharge our mobile phones after prolonged use, sleep has an important restorative function in recharging the brain. Maintaining a regular sleep-wake cycle allows the body's natural rhythm to be reset every day; in turn, this restoration optimizes brain functioning. There is clear evidence that sleep deprivation has a significant effect on emotions. The results of one pivotal study from 2007 indicate that a night of restful sleep reset brain reactivity in order to prepare for emotional challenges the next day. It also showed that the absence of sleep could substantially compromise the neural capacity to move new experiences to memory 4. Therefore, it appears that sleep before learning is critical in preparing the human brain for next-day memory formation, a worrying finding considering society's increasing erosion of sleep time.

Sufficient sleep, especially REM sleep (the "deeper" stage of sleep), facilitates the brain's processing of emotional information. During sleep, the brain works to evaluate and remember thoughts and memories, and it appears that a lack of sleep is especially detrimental to the consolidation of positive emotional content. This can influence mood and emotional reactivity and is linked to mental health disorders and their severity.

Aging and sleep – an important connection

Interestingly, it has been demonstrated that sleep deprivation is not only connected with mental health issues, but it also has adverse effects on cardiovascular health, increasing the likelihood of developing diseases such as diabetes, high blood pressure and heart failure, and neurological health, increasing the risk of Alzheimer's disease 5,6. In general, lack of sleep increases the inflammation levels in your body, and this contributes to premature aging and other health complications.

The physical consequences of sleep deprivation are:

• Increased levels of inflammation
• Increased levels of the stress hormone cortisol
• Weakened immune system
• High blood pressure
• Higher blood sugar levels
• Food cravings and weight gain
• Memory issues
• Decreased brain performance
• Low sex drive

Most of these physical manifestations are linked with aging.

Beauty sleep

Skin is a good example of a clear connection between signs of the passing of time and sleep. Sleep deprivation, especially if chronic, leads to increased signs of intrinsic skin aging (reduced elasticity, uneven pigmentation, and fine lines) and a much slower recovery rate after skin barrier disruption 7.

The saying “beauty sleep” has a lot of truth indeed in it, and sleeping is the closest thing to a youth fountain you can find. If you constantly get 7-9 hours of sleep every night, your skin will thank you. Some of the advantages of getting enough rest for your skin are fewer wrinkles, a glowing complexion, and brighter and less puffy eyes.

What Contributes to Sleeping Issues?

The things that affect our sleep differ for everyone. They can include stresses or worries (for example, issues with money, housing, or work), problems with where you sleep (for example, if you sleep somewhere uncomfortable or you're easily disturbed), health conditions relating to sleep, also known as sleep disorders, being a parent or carer, some medications, use of alcohol or recreational drugs, working at night or being a shift worker, current or past trauma and mental and physical health problems, many of which can affect your sleep. The good news is that, whatever the underlying issues resulting in sleeping problems, you can take steps to improve your situation.

Is it Possible to Improve Sleep Issues?

In short, yes. It is very possible. These are steps you can take to improve your sleep and age better:

Lifestyle changes. Most people know that caffeine and good sleep do not go hand in hand, but so do alcohol and nicotine. Alcohol initially depresses the nervous system, which can help fall asleep, but the effects wear off in a few hours, and people wake up. Nicotine is a stimulant, which speeds heart rate and thinking. Giving up these substances is best, but avoiding them before bedtime is also an option.

Sleep hygiene. Good "sleep hygiene" is the term often used to include tips like maintaining a regular sleep-and-wake schedule, using the bedroom only for sleeping, and keeping the bedroom dark and free of distractions like the computer or television.

Relaxation techniques. Meditation, guided imagery, deep breathing exercises, and progressive muscle relaxation can counter anxiety and racing thoughts leading to sleep disturbances.

Cognitive-behavioral therapy. Because people with insomnia tend to become very worried about not falling asleep, cognitive-behavioral techniques can help them change negative expectations and build more confidence to have a good night's sleep.

If sleep problems persist despite the lifestyle or behavioral changes suggested above, you might need help from a doctor. A good idea would be to keep a sleep diary for a couple of weeks before your visit so, together with your doctor, you can better investigate the problem. Doctors will look for any underlying medical or mental health reason for your sleep issue and may suggest changes to your routine or lifestyle to help improve your sleep. If these don't work, they may suggest sleeping pills for insomnia problems. In the short term, sleeping pills can help, but they quickly become less effective and can even make your sleeping problems worse. Another issue to consider is that they can also be very addictive. For all these motives, sleeping pills are generally prescribed at the lowest dose and for a short period of time until you are able to restore a healthier sleeping pattern. If your problems persist, your doctor may want to refer you to a specialist sleep disorder clinic.

Seven steps to improve your sleeping habits and age better:

1. Establish a regular sleep-wake cycle - try to go to sleep and wake up more or less at a consistent time.
2. Try to ensure that you have a comfortable bed and bedroom – tailor noise, light, and temperature to your preferences.
3. Limit the use of stimulants - such as caffeine, nicotine, and alcohol near bedtime.
4. Avoid drinking excessive liquids - especially in the evening, to minimize chances of waking up to empty your bladder.
5. Avoid going to bed until you are drowsy and actually ready to sleep - Most people who suffer from insomnia spend more time in bed lying awake rather than actually asleep.
6. Regular daily exercise - Regular aerobic activity helps people fall asleep faster, spend more time in deep sleep, and awaken less often during the night. However, avoid exercising too late in the evening as this could be stimulating.
7. Avoid electronic devices late at night - such as computers, mobiles, tablets, and so on; the bright light can be overly stimulating and keep you awake.

About Arianna Ferrini

Arianna is a postdoctoral research fellow at University College London (UK). She holds a PhD in Tissue Engineering and Regenerative Medicine from Imperial College London (UK) and an MSc in Medical and Pharmaceutical Biotechnology from the University of Florence (Italy). She's an enthusiastic science communicator and works as a freelance writer and editor.

References

1. https://www.sleepfoundation.org/
2. https://pubmed.ncbi.nlm.nih.gov/30042701/
3. https://journals.lww.com/co-pulmonarymedicine/Abstract/2016/11000/Sleep_deprivation__a_mind_body_approach.9.aspx
4. https://www.nature.com/articles/nn1851#:~:text=Whether%20sleep%20before%20learning%20is,resulting%20in%20worse%20subsequent%20retention.
5. https://pubmed.ncbi.nlm.nih.gov/30630005/
6. https://pubmed.ncbi.nlm.nih.gov/31102663/
7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5706759/