Why sleep matters for your health
We have all heard how important it is to get enough sleep. We also know how cranky, irritable or exhausted we can feel if we don't get enough shut eye at night, (in fact I had this very experience last week). I definitely felt a little frazzled and certainly wasn't as fun to be around. We know that a lack of sleep can turn even the most serene individual into a grump, but I wanted to share with you some other reasons why sleep should matter to you... and your overall health.
A little background on sleep buzz words and terminology:
Circadian Rhythm: What the heck is that really? Well it is a group of mental, physical and behavioral changes that follow a 24 hour time period. This means circadian rhythms contribute to sleep-wake cycles, but also to hormone release and other important signaling communication in your body. You may have heard of the hypothalamus which is a region in your brain that is often referred to as the "Master Clock" which is made of up groups of nerve cells that help to control hunger, body temperature, sleep, and fatigue. The most important contributor to circadian rhythm is light-dark cycle.
Two of the hormones that are big players in your circadian rhythm are Melatonin and Cortisol. Melatonin contributes to drowsiness and helps you to lower your body temperature prior to sleep. BUT because melatonin release is triggered by darkness if your body is exposed to too much light in the evening time your melatonin release can be suppressed. Fact: even ordinary indoor light can inhibit the production.
Cortisol is one of your body's primary stress hormones and it is linked closely to your body's sleep/wake patterns. In healthy individuals we see a pattern of cortisol with levels highest in the morning right after you wake, and then slowly decreasing throughout the day. The cycle begins again with secretion of cortisol sometime after midnight preparing again for the next day. When this cycle gets out of wack, we call it dysregulation. This dysregulation can mess with our circadian rhythm and health in many other ways.
So how does this tie into our health?
Sleep and it's impact on our...
Immune System. Even if you pull only one all nighter (and I think we all have) studies have found significant increases in markers of inflammation, and an over-activation of the immune system. It has also been found that reducing your sleep for only 3 nights in a row to 4-5 hours a night has similar effects. Another reason sleep is so closely linked to our immune system is that when we sleep certain disease fighting substances are created. These necessary functions are inhibited when we don't sleep leaving us more susceptible to infections.
Disease Risk. Disrupting circadian rhythms has been proposed as a risk factor for: Type 2 DM, CA, Heart Disease. You may be saying, well I'm young I don't have to worry about this....well you do regardless of age. One study in adolescents showed that teens without adequate sleep had a high risk for cardiovascular events.
Weight. The link between sleep deprivation and weight gain has been studied heavily over the past 10 years. Losing out on sleep has been shown to increase hormones that signal hunger, and decrease hormones that signal satiety and thus your body ends up constantly thinking it is hungry. Not enough sleep also has been shown to decrease glucose tolerance and insulin sensitivity (which means elevated blood sugar and inability for cells to deal with insulin). If you are struggling to reach your body's healthy weight, simply starting with a focus on quality sleep can be a great shift.
Mood. Chronic sleep deprivation has also been proposed as a link in mood disorders. Research has shown a correlation between chronic insufficient sleep and mood disorders such as depression, and anxiety. This may be because sleep helps to regulate the flow of chemicals such as epinephrine, dopamine and serotonin.
Mortality. After seeing some of the potential risks that inadequate sleep has on our health perhaps the biggest (and scariest) impact is that on our life expectancy. Studies have shown that an average of 5 hours or less per night of sleep increased the risk of mortality by approximately 15 percent. Yikes.
So how much is enough? This is a tough one to answer and the reason is there is no perfect number. It differs from person to person but the current guidelines for adults suggest an average of 7-9 hours per night.
If this post is seeming a bit scientific, or a little disheartening, don't worry! We will get you catching those Zzzz and contributing to your renewed health. I will be sharing some strategies to help improve your sleep in an upcoming post. So for now, when you are faced with that all nighter, (or are about to get swept up into watching that Netflix series until 2 am) remember friends...sleep matters!