Sleep, Aging, And Your Brain - What You Must Know

You’ve likely heard the old saying advising people to get their "beauty sleep". Turns out, that similar to many other folk sayings, there is more wisdom in those words than one would imagine. Getting the right amount of sleep is critical, not only for your health but for optimal cognitive functioning as well as your mood and ability to focus.

To make things even more interesting, recent research is also starting to uncover more about what happens biologically when you don’t get enough sleep. The results of this research are startling: not getting enough sleep actually causes you to age faster. Plus, a lack of sleep even makes your skin look older!

But how does this work? What is it about losing sleep that causes your body to age? How much sleep do you actually need? And what are some of the things you can do to ensure your body is getting quality sleep? Let’s take a deeper look into the world of sleep and aging to get the answers to these questions and more.

First of all, let’s do a little review on the physiology of sleep, as in many cases, it’s all about the quality of sleep that you need to get, not the absolute number of hours. So it’s important to understand the various stages of sleep.

Why Do Humans Sleep?

Before we get to that, have you ever really thought about why we sleep? As strange as this may seem, scientists are not really sure why we sleep. Researchers can tell us a great deal about what happens when we sleep but as to why it’s really necessary, scientists don’t really have a single definitive answer.

One of the most compelling sleep theories is known as the restorative theory, which says that sleep functions to restore your body from the wear and tear it undergoes while you are awake. This theory is backed up by research demonstrating that bodily functions such as tissue repair, muscle growth, formation of new proteins, and the release of growth hormone, occur mostly and in some cases, only while you are sleeping. All of these processes are restorative ones.

But besides restorative functions, sleep is also strongly related to changes in the structure and organization of the brain. When you don’t get enough sleep, this negatively affects your ability to learn as well as to perform certain tasks, and also negatively impacts your memory. So instead of serving a single primary function, sleep seems to serve in a variety of ways.

The Five Stages Of Sleep

Now let’s go back to what happens after you go to sleep at night. There are five stages of sleep, divided into two parts: REM sleep and non-REM sleep. REM stands for rapid eye movement sleep and it’s during this stage that your eyes move rapidly back and forth. If you look at someone sleeping and they are in REM sleep stage, you can see this back and forth movement of their eyes under their closed lids.

In Stage One, you may not even realize you are sleeping. This stage only lasts from five to 10 minutes and sometimes you may feel like you are falling. This causes your muscles to involuntarily jerk, and you may see some dreamlike imagery known as hypnagogic imagery.

Next is Stage Two or light sleep. Your heart rate slows, eye movements stop, brain waves become slower, and your body temperature drops in preparation for Stage Three or deep sleep.

Stage Three is the first of the Deep Sleep stages and your brain produces slow delta waves with bursts of faster waves. This is the stage where you may experience sleepwalking or talking in your sleep.

Stage Four is a deeper version of Stage Three, with your brain now exclusively producing delta waves. If you try to wake someone up who is in this stage you will find it very difficult, and if you are awakened in Stage Four you may feel disoriented for a bit. This deep sleep stage is extremely important, as it’s in this stage where your body repairs tissues, strengthens your immune system, and builds up muscle and bones. As you age, you get less of this deep sleep stage.

Stage Five, REM or rapid eye movement sleep, occurs about 90 minutes after you fall asleep as you come out of stage four. In this initial cycle, the first time you enter REM will last about ten minutes, but throughout the night as you go back through the stages, each REM period gets longer and longer, with the final one lasting as much as an hour.

The REM sleep stage is much more active than other stages. Your breathing as well as your heart rate speeds up, your brain becomes more active and you may have intense dreams. Babies spend nearly 50 percent of their total sleep time in REM as opposed to adults, who spend about 20 percent in REM.

While all of the sleep stages are important, deep sleep is doubly so. As we said earlier, as you age, you are likely to get less and less deep sleep. Most of the deep sleep you get is in the first part of the night. In later cycles, deep sleep decreases and is replaced by lighter Stage 2 sleep, and REM sleep, the dreaming stage, gets longer and longer as the night progresses.

Deep sleep is very effective in suppressing your drive to sleep, which gradually increases over the day while you are awake. So if you take a daytime nap of about 20 minutes, it’s not too likely to interfere with your night-time sleep. But if you nap longer, you may go into deep sleep and that can spell major trouble with getting to sleep that night.

Deep sleep is important for another reason, as it’s during these stages that human growth hormone, critical to cell repair and muscle building, is released. The release of growth hormone stops if deep sleep is interrupted. Deep sleep is important because it clears the brain in preparation for new learning. So when you wake up feeling really refreshed, and you can report that you “got a good night’s sleep,” it’s very likely that you also got an adequate amount of deep sleep. This is why deep sleep is also known as restorative sleep. This is important to know because, in many scientific studies, such as the ones we discuss below, the researchers will ask the participants to fill out a questionnaire assessing their sleep quality.

How much sleep do you need? According to the CDC (Centers for Disease Control) adults aged 18 to 60 need at least eight hours of sleep a night, and folks 60 and over need eight to nine hours a night.

Lack Of Sleep Accelerates Aging

One of the most surprising research findings on lack of sleep showed that sleep deprivation is directly linked to aging skin, so maybe that old adage about “beauty sleep” was correct after all! In a 2013 clinical trial done at the Case Western Reserve Medical Center, researchers found that participants who had poor quality sleep (based on the number of hours of sleep and self-report of quality) showed accelerated and premature signs of skin aging (as measured by fine lines, uneven pigmentation, and slackening of skin and reduced elasticity) and a weakened ability to repair itself at night. Participants who got consistent good quality sleep not only had younger appearing skin but their skin actually had the ability to recover more efficiently from a stressor, such as a mild sunburn.

But sleep deprivation is much more than skin deep. As we have already seen, as you age, your ability to get quality deep sleep becomes less. In fact, sleep difficulties are quite common in people who are 55 and over, so common in fact, that it’s become accepted as normal. Also considered “normal” is a certain shrinkage of certain brain structures. But in a study done at the Duke-NUS Graduate Medical School in Singapore, the researchers looked at the effects of a short-term lack of sleep on older individuals. Prior to this, most studies focused on a lack of sleep on thinking and memory in adults of all ages but had not looked at how a lack of sleep might physically change the brain and affect cognition in older adults.

This Singapore study analysed data obtained by healthy adult participants who participated in the larger Singapore Longitudinal Aging Brain Study and who had previously had their brain volumes measured by MRI as part of that study. Two years later, when the researchers repeated the scans and cognitive tests, they found that participants who had fewer hours of sleep had evidence of more rapid brain shrinkage as well as declines in cognitive performance as compared to those who got adequate sleep.

If you think it takes many months of chronic sleep deprivation for these changes to show up, you would be wrong. Research published in an online supplement of the journal Sleep and presented June 10th at SLEEP 2015, the 29th annual meeting of the Associated Professional Sleep Societies, showed that just one night of lack of enough sleep in older adults was enough to activate the cellular chemical and genetic pathways that promote biological aging. In fact, for each hour of less sleep, the decline in cognitive performance rose by 0.67 percent and ventricle enlargement on MRI (an indication of brain shrinkage) increased by 0.59 percent.

How To Improve The Quality Of Your Sleep - Seven Best Practices

At first glance, it might seem that the brain changes and cognitive declines that accompany the increasing sleep challenges that go along with aging are inevitable. But that’s not necessarily true. There is a lot you can do to improve the length and the quality of your sleep.

Here are 10 best practices:

One – Set aside at least 8 hours and 30 minutes for sleep between 9.30pm and 7am. This time window correlates with a major part of the circadian rhythm of sleep for most people, which will maximize sleep efficiency as a result.

Two - Stick to a consistent sleep schedule, waking up at the same time each morning, even on the weekends.

Three - Try to get morning sun exposure on your face as soon as possible after you get out of bed. This sets your biological clock for the day, making it easier to get to bed on time that night. Morning sun will also improve your mood.

Four - Cut off caffeine intake by early afternoon to give it time to get out of your system.

Five - Two to three hours prior to bedtime, cut off your electronic devices. If you must work, consider using a pair of blue-blocking glasses to block blue light from your eyes. Blue light signals your brain to stay awake and alert and exposure to it in the evening can disrupt your sleep. It’s also important to sleep in a totally dark bedroom, as exposure to even low levels of light in your bedroom can not only disrupt the production of the sleep hormone melatonin but has been associated with depression.

Six - Limit a daytime nap, if you take one, to no more than 30 minutes, and no later than 3pm.

Seven - Avoid eating after 7pm, especially big meals. This will give your digestive system time to rest.

Eight - In the hour or so leading up to bedtime, take some time to unwind. Dim the lights in your house as well.

Nine – Take a clinical-grade NAD+ booster, such as Nutriop® Life, Pure-NMN and Pure-NAD+, on a daily basis.
In many studies, NAD+ supplementation normalizes the whole body circadian rhythm signaling. That’s because NAD+ directly activates a special “longevity” gene called Sirt1, which, besides promoting the health of telomeres in DNA, maintains a central circadian function during aging by amplifying circadian gene expression.

Ten – Exercise regularly, ideally in the morning or early afternoon.

If you go to bed and you just can’t sleep, it’s better to just get up and do something else until you feel sleepy again. Remember not to expose yourself to bright light though, or this can make it nearly impossible to get to sleep. Take some time to evaluate your sleep habits and make the necessary changes. Your brain, and your skin, will thank you for it!

References:

1. Oyetakin-White P, Koo B, Matsui M, Yarosh D, Fthenakis C, Cooper K, Baron E. - Effects of Sleep Quality on Skin Aging and Function. J Invest Dermatol. 2013; :S126–S126.

2. Lo JC, Loh KK, Zheng H, Sim SK, Chee MW. Sleep duration and age-related changes in brain structure and cognitive performance. Sleep. 2014 Jul 1;37(7):1171-8. doi: 10.5665/sleep.3832. PMID: 25061245; PMCID: PMC4098802.

3. Kenji Obayashi, Keigo Saeki, Norio Kurumatani, Bedroom Light Exposure at Night and the Incidence of Depressive Symptoms: A Longitudinal Study of the HEIJO-KYO Cohort, American Journal of Epidemiology, Volume 187, Issue 3, March 2018, Pages 427–434, https://doi.org/10.1093/aje/kwx290