The importance of sleep
Updated: Nov 21, 2021
Why do we need it?
Sleep is a time of rest, rejuvenation and strengthening, not only for the body, but for the mind as well. Research has shown that during sleep, our cells regenerate at a higher rate than when we are awake. That is why when we are ill, our body craves rest – it is nature’s way of telling us to lie down and get some sleep. It knows what it needs.
During sleep, cytokines, a type of protein that targets infection and inflammation, are both produced and released, strengthening the immune system.
Another important role of sleep is to help our minds solidify and consolidate memories. During the day, our brains take in a vast amount of information, and it is while we are asleep that this information are processed and stored into long-term memory.
How much do we need?
According to the National Sleep Foundation, adults between the ages of 18 and 64 need between 7 and 9 hours of sleep per night while those over 64 need slightly less sleep, between 7 and 8 hours per night. (Sleep requirements of children and teenagers is much greater, because these are periods of critical growth and learning, but that is beyond the scope of this article.) As with water, our personal needs for sleep will vary slightly, because we are all individuals with unique body chemistry, lifestyles and metabolic rates. We will also need more sleep in times of strenuous physical exertion (such as when training for a marathon), or when we are fighting or recovering from an illness or injury.
Research shows that we need at least 7.5 hours of sleep each night for optimal cortisol control. Chronically elevated cortisol levels wreak havoc with our health. It weakens our immune system, can lead to insulin resistance, diabetes, high blood pressure and increased appetite through lower leptin levels (the hormone that tells us we are not hungry) which eventually contributes to weight gain and quite often, obesity.
Research has also linked chronic sleep deprivation to such things as: slower reaction time, memory loss, confusion, irritability, moodiness, anxiety and depression. You can see from this list that it is important to your long-term health to develop a daily habit of getting adequate, good quality sleep!
Does it matter when I get it?
Humans have a natural circadian rhythm (sleep/wake cycle) which is an internal clock in your brain (part of the hypothalamus) which cycles between alertness and sleepiness at fairly regular intervals over the 24 hours of each day. For most adults, the strongest sleepiness cycle occurs between 2:oo a.m. and 4:00 a.m. with a somewhat smaller dip in energy between 1:00 p.m. and 3:00 p.m. The highs and lows will be less pronounced if you are all caught up on your sleep, but when you are sleep-deprived, the lulls will hit especially hard.
Your natural circadian rhythm tends to coincide with daytime and nighttime, because when it becomes dark, your eyes send a signal to the hypothalamus, and your brain sends a signal to the body to release melatonin, which makes you feel tired. When you work the night shift, travel across several time zones, stay up too late or take a long nap during the day, your rhythm is interrupted and it becomes more difficult to either fall asleep and/or stay asleep.
In some parts of the world, (examples are Italy, Spain, Greece, Mexico, and Costa Rica) the afternoon nap is embraced to the point where businesses close for an hour or two after lunch so that employees can go home for lunch and a snooze. North America isn’t there yet, though some companies are starting to embrace the concept of becoming “nap friendly”.
At the end of the day (no pun intended), consistency is the key to maintaining a healthy, natural circadian rhythm. Go to bed at night and wake up in the morning at the same time each day if possible. If you do nap, do so at the same time each day for the same amount of time.
Is all sleep created equal?
There are several stages to sleep. In the first stage, we are just falling asleep, but still somewhat awake. In the second stage, during the onset of sleep, our body temperature starts to fall. The third stage is the deepest, most restorative stage, when our blood pressure drops, our muscles relax, energy is restored and the blood supply to our muscles is increased. The last stage, which occurs about 90 minutes after we fall asleep, is referred to as REM or rapid eye movement sleep. This stage is when dreaming occurs, the muscles are turned off, and energy is supplied to our brain and body.
When our sleep is interrupted by noise, racing thoughts, trips to the bathroom, etc., we have to start over at the first stage of sleep. If sleep is interrupted more than a few times during the night, we may never reach the deepest, most beneficial stages of sleep. So this is why though you may be spending 8 hours in bed, and may think that you are sleeping for most of it, you may still not feel rested in the morning.
There are also some differences between the genders when it comes to sleep. Men and women have slightly different circadian rhythms, with men being closer to the true 24 hour cycle, whereas women have a slightly shorter cycle (6 minutes on average). This means men are more likely to be night owls and women are more likely to be early birds. As well, men are harder hit by periods of sleep deprivation and recover less quickly from a lack of sleep.
Why can’t I sleep?
There are a number of factors that could be affecting your ability to fall and stay asleep. Some are lifestyle issues, some are dietary choices and some are environmental:
Lifestyle: One of the most common reasons for poor sleep is stress. While lack of adequate sleep causes increased cortisol levels, the increased cortisol also then causes problems with sleep, thereby creating a vicious cycle. Stress management is critical to getting a good night’s sleep. You may need to stop taking that nap after dinner, request a more regular work shift from your boss, or shut all screens off earlier in the evening.
Dietary: Some nutrient deficiencies can cause insomnia including calcium, vitamin B6, folic acid and vitamin D. Conversely, you may be eating too much of the wrong foods too close to bedtime, causing a spike in your blood sugar. It may be caffeine, nicotine or alcohol that’s keeping you up. There are also certain snacks that may help you sleep.
Environmental: Things to consider are temperature of the room, noise, light sources, and electromagnetic fields from such things as alarm clocks and electric blankets.
A host of other issues may also be affecting your sleep, including medications, allergies and/or asthma, thyroid issues, digestive problems such as acid reflux, and arthritis or other pain.
So what do I recommend?
Our bodies will tell us when it needs sleep, but we do need to listen to it. Often we get caught up in our busy day and simply don’t pay attention to the cues our body is sending. Some of the early signs of sleep deprivation are: yawning moodiness, fatigue, irritability, depressed mood, difficulty learning new concepts, forgetfulness, inability to concentrate or a “fuzzy head”, lack of motivation, clumsiness, increased appetite and carbohydrate cravings, and reduce sex drive.
The sooner you identify and address your sleep issues, the easier they will be to sort out, and the less likely they will become a chronic problem with the serious health effects mentioned above.
I do not recommend taking over the counter sleep aids, or using things like cold medications to knock you out. These are only band-aid solutions and don’t address the underlying issue(s). They are generally toxic, leading to potentially harmful side effects, and may even be addictive.
Whether you are having only occasional issues with sleep, or have full-on insomnia, please reach out to us to see how we may be able to help. We can suggest stress management tools to help manage your cortisol levels, or better yet, complete a full assessment to make dietary and/or supplement recommendations for your unique situation.