Sleep and the Aging Brain

Terry Whitehead | Wellness Committee Member

This article is for information purposes only. Before making any decisions about your health, you should always consult your doctor and other healthcare professionals.

We all know that quality sleep is essential for our health, but its impact on brain function is often underestimated. I recently listened to The Gut-Brain Solutions: New Frontiers Conference hosted by Sara Otto – the doctors she interviewed were so knowledgeable! I focused on the importance of sleep and hope that you will take away something important from this article.

According to Dr. Will Cole, DC, like many parts of our body, our gut health can influence our cognitive health. When the gut is out of balance, it can send distress signals to the brain via the vagus nerve – a sort of neurochemical pathway between the brain and other vital organs. This gut-brain connection may contribute to symptoms like brain fog, mood swings, memory issues, and even depression. But with a consistent and restorative sleep routine, we can maintain brain function as we age.

The Stages of Sleep

Knowing the stages of sleep can be helpful to understand what healthy sleep looks like. If you have a sleep disorder, or find you do not feel well-rested when you wake up in the morning, there is probably some disruption happening during one or more of these stages.

The sleep cycle consists of alternating periods of non-rapid eye movement (NREM) and rapid eye movement (REM), which last between 90 to 120 minutes. For most adults, we experience four to six cycles every night.

N1: Light Sleep

In this phase, it important to slow down and develop good sleep rituals. It is a meditative moment. This stage happens right after you first fall asleep and usually lasts under ten minutes. Your brain activity slows down, and breathing and heart rate decrease, preparing your body to enter a deep sleep. It is the easiest to be woken up during this ‘light sleep’.

N2: Moderate Sleep

This slow-wave stage plays a key role in learning and memory. Here is when your brain consolidates all the information absorbed during the day and promotes motor skill learning for activities such as playing an instrument. It also primes the brain for problem-solving and creativity. About half of your total sleep time is spent in this stage.

N3: Deepest Non-REM Sleep

In the deep sleep phase, the brain helps the body repair tissues, rebuild muscles, and restore energy. It also maintains a healthy immune system so that we can fight off disease and infections. According to Dr. Anne Satta, the glymphatic system flushes toxins from the brain, and the lymphatic system flushes toxins from the body. If we have chronically impaired sleep, these systems can become compromised and will not be able to drain efficiently.

Dr. Rodger Murphree, DC, explains during sleep, the body produces important hormones and neurotransmitters like DHEA, melatonin, and serotonin, each following its own unique rhythm. Melatonin is mainly produced at night to support sleep, while DHEA and serotonin follow more complex daily cycles, influenced by both sleep and periods of wakefulness. Without these chemicals, our stress will be magnified by things like changes in the weather, bright lights, loud noise, and traffic jams. Serotonin also increases our pain threshold and makes us less irritable. Melatonin helps reduce inflammation and neutralizes harmful free radicals (unstable molecules that can damage cells, DNA, and tissues).

REM: Rapid Eye Movement

The rapid eye movement (REM) stage of sleep is known as the dream phase. There is more activity involving memory and emotional regulation, and less activity in the frontal brain involved in analytic thinking. We combine fragments of events and memories experienced during the day in novel and sometimes bizarre ways while we are dreaming. During this stage, our brains strengthen and process the emotional memories we form during the day. Sleep helps us regulate our moods and maintain emotional well-being. Otherwise, we may become irritable, anxious, or depressed.

Changes in Sleep as We Age

As we age, we experience less slow-wave and REM sleep. This means our memory consolidation may be impeded. We also become vulnerable to sleep disturbances that cause poor sleep and low brain oxygen. Sleep deprivation impairs our cognitive abilities, making it more difficult to concentrate and process information.

Many of us suffer from physical ailments which can make it difficult to sleep. The most common reason is snoring. Some partners have sleep apnea, which may require sleeping with a machine. Others have breathing problems, arthritis, or cannot sleep lying down or in certain positions. Some may have restless leg syndrome, or they need to get up to use the bathroom often in the middle of the night. Perhaps you suffer from insomnia, tossing and turning all night. These conditions can affect not only the individual’s sleep but also the sleep of a partner.

Ways to Promote Better Sleep

According to a 2017 survey from the National Sleep Foundation, almost one in four married couples sleep in separate beds or even separate rooms, also known as ‘sleep divorce.’ Some couples have a higher quality of sleep when they implement sleep divorce, while others sleep better with their partner – do what works best for you!

It might be helpful to use a sleep diary to keep track of your sleep schedule for at least two weeks. This will provide objective information regarding the consistency of your sleep routine, as well as the association between sleep and your level of alertness during the day.

Sleep experts such as Dr. Suzanne Bertisch from Harvard suggest being consistent with your bedtime routine. Train your body by going to bed and getting up at the same time each day. Only sleep when you are sleepy and do not spend too much time awake in bed.

Optimize your sleep environment. Are your bed, sheets, and pillows comfortable? Is the temperature cool? You might prefer to use eye masks, ear plugs, or white noise to help you settle. Use an orange light with a physical book before you sleep can help – no screens. Reserve your bed for sleep and intimate moments only, and avoid reading or doing work activities while in bed. Keep blue light out of your bedroom by not watching TV in bed or scrolling on your smartphone.

A study in a large sample of older individuals living in the Mediterranean region shows that midday napping is associated with higher levels of successful aging. Dr. Sarah McKay, a neuroscientist, says napping during the day is helpful, but don’t go into the deep sleep stage – wake up after 20 minutes.

Suggested sleep aids that promote relaxation include a bath with Epsom salts, drinking a cup of chamomile tea, or spraying lavender on your pillow. You might also explore sleep-supporting supplements, such as melatonin, or natural herbal options like GABA (gamma-aminobutyric acid) and ashwagandha, which are commonly available at most drugstores.

Better Sleep, Sharper Mind

Sleep is one of the most powerful tools we have for maintaining brain health as we age. By understanding the stages of sleep and developing a better sleep routine, we can age with more vitality, clarity, and emotional balance. Happy sleeping, everyone!

Terry Whitehead
Wellness Committee Member