WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
You’re probably already aware that a good sleep schedule is a vital component to a healthy lifestyle, but did you know that when you don’t get enough sleep, your brain actually starts to eat itself?
I don’t mean that in the literal sense of the word, but research from the Marche Polytechnic University in Italy shows that astrocytes, a type of glial cell in the brain that normally gets rid of unnecessary nerve connections start to break down healthy nerve synapses in response to chronic sleep deprivation.1
In the study, mice were divided into four groups: well-rested (six to eight hours of sleep); spontaneously awake (periodically woken up); sleep-deprived (kept awake for an additional eight hours); and chronically sleep-deprived (kept awake for five days straight).
The researchers then looked at astrocyte activity in each of the four groups. In the well-rested mice, 5.7% of brain synapses had astrocyte activity. That number jumped slightly to 7.3% in the spontaneously awake mice. But in the mice that were sleep-deprived and chronically sleep-deprived, those numbers jumped again to 8.4% and 13.5%, respectively.
How the Brain Normally Functions
To understand what this increased astrocyte activity means, you must first understand how the brain normally functions. Your body and your brain constantly go through cellular cleansing processes. In the brain there are two types of glial cells that are responsible for clearing out old or damaged cells and synapses.
Microglial cells initiate a process called phagocytosis to remove debris, pathogens and dead cells from the brain.2 Astrocytes are supporting cells that provide structural support, insulate surfaces and protect the brain during inflammation and injury.3 These are complementary roles that help repair and restore the brain while you sleep and get you ready for a new day. Normally, that’s a good thing.
But when you don’t get enough sleep, astrocyte activity increases and the cells actually start to exhibit behavior similar to the microglial cells, eating waste and engaging in excessive cleansing — a physiological process called astrocytic phagocytosis.4
When this happens, instead of targeting only dead or damaged cells, the astrocytes start to eat away and destroy healthy synapses too. Over time, this can lead to chronic brain diseases like Alzheimer’s disease and other forms of neurodegeneration, like Parkinson’s disease.
Other Health Problems Associated With Sleep Deprivation
Although it’s a big problem, increased astrocyte activity and destroyed brain synapses aren’t the only problems associated with chronic sleep deprivation. If you’re not getting enough good quality sleep, it can also lead to several acute and chronic symptoms and health conditions, including:
Increased risk of accidents due to decreased vigilance and longer reaction times5 |
Fatigue and restlessness |
Reduced ability to perform tasks |
Impaired cognitive ability and memory |
Lack of motivation |
Decreased productivity at work |
Increased risk of heart disease, diabetes and high blood pressure6 |
Imbalanced hunger hormones and weight gain |
Increased risk of depression, anxiety and mental disorders |
Increased irritability |
Diminished immune system and increased susceptibility to infection |
Increased likelihood of alcohol abuse |
Decreased life expectancy |
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How Much Sleep Do You Need?
It’s important to make sure you’re getting enough sleep to avoid damage to the brain and chronic health problems. But how much is enough? A general rule of thumb is to get eight hours of sleep, but the exact amount that’s right for you depends on your age, your overall health and your daily activities.
The National Sleep Foundation breaks recommendations down by age to make sure you’re getting enough sleep:7
| Age |
Recommended Hours of Sleep |
0 to 3 months |
14 to 17 hours |
4 to 11 months |
12 to 15 hours |
1 to 2 years |
11 to 14 hours |
3 to 5 years |
10 to 13 hours |
6 to 13 years |
9 to 11 hours |
14 to 17 years |
8 to 10 hours |
18 to 64 years |
7 to 9 hours |
65 and older |
7 to 8 hours |
Keep in mind that these are general guidelines and getting an hour more or an hour less may be appropriate, depending on your lifestyle, health circumstances and how you feel. If you’re productive, energetic, happy and healthy on seven hours of sleep, there’s no need to bump that up to eight based solely on a chart.
Tips on Getting a Good Night’s Sleep
It’s important to note that getting a good night’s sleep means quickly falling asleep, reaching a deep, restorative sleep and staying asleep. Going to bed at 10 p.m. and then tossing and turning all night until 6 a.m. doesn’t count as a good eight hours of sleep.
If you’re having trouble getting a good night’s sleep, there are a number of things you can do to improve your sleep hygiene. Just like eating a good diet, it’s important to prioritize these sleep tips so you can achieve optimal rest. If you practice all of these things regularly, you’ll be well on your way to a good night’s sleep and making sure your brain stays healthy:
Turn your bedroom into an oasis for sleep — Your bed is a place to sleep and rest comfortably. The only other two activities that you should do in bed are read and engage in intimate relations with your partner. Anything else, such as work, computers, cellphones or watching television will reduce the quality of your sleep.8
Reduce noise from pets or outdoor activities. You might consider removing your pet from the bedroom or using a white noise machine to cover any outside noises.9 |
Establish a soothing pre-bedtime routine — Humans are creatures of habit. When you establish a soothing bedtime routine, you're more likely to fall asleep easily. Taking a warm bath, reading a good book or doing some relaxation exercises before bed may help you fall asleep easier.
If you have trouble falling to sleep one night, it's better to leave the bedroom and read quietly than to try even harder to fall asleep.10 I would strongly recommend using blue-blocking glasses if you do this, to prevent your reading light from further depressing your melatonin production. |
Keep a consistent schedule — When you go to bed and wake up at the same time every day, your body becomes accustomed to the routine. This helps regulate your circadian rhythm so you fall asleep and stay asleep all night. Keep a consistent sleep schedule, even on the weekends.11 |
Get plenty of bright sunlight exposure in the morning and at noon — Exposure to bright light first thing in the morning stops production of the sleep-inducing hormone melatonin and signals to your body that it's time to wake up. Outdoor sunlight is best, so you might even want to take a quick walk outside. Taking your walk outdoors — either first thing in the morning and/or around noon when the sun is high — gives you more exposure to bright sunlight.
I take a one-hour walk every day in the bright sunlight on the beach, so along with boosting my vitamin D, I also anchor my circadian rhythm at the same time and I rarely ever have trouble sleeping. |
At sundown, dim your lights (or use amber-colored glasses) — In the evening (around 8 p.m.) you'll want to dim your lights and turn off electronic devices. Normally, your brain starts secreting melatonin between 9 p.m. and 10 p.m., and these devices emit light that may stifle that process, throwing your circadian rhythm out of whack and disrupting your sleep.12
After sundown, shift to a low-wattage bulb with yellow, orange or red light if you need illumination. A salt lamp illuminated by a 5-watt bulb is an ideal solution that will not interfere with your melatonin production. If using a computer or smartphone, install blue light-blocking software like f.lux, which automatically alters the color temperature of your screen as the day goes on, pulling out the blue wavelengths as it gets late.
The easiest solution, however, is to use amber-colored glasses that block blue light. I found an Uvex model (S1933X) on Amazon that costs less than $10 and works like a charm to eliminate virtually all blue light. This way you don't have to worry about installing programs on all your devices or buying special light bulbs for evening use. Once you have your glasses on, it doesn't matter what light sources you have on in your house. |
Check your bedroom for electromagnetic fields (EMFs) — EMFs can disrupt your pineal gland and the production of melatonin and serotonin,13 and may have other negative effects as well. To do this, you need three types of meters, gauss meter for magnetic fields, electric fields and RF or radiofrequency fields |
Exercise daily — Your body thrives on movement and exercise, which reduces your risk of cardiovascular disease and metabolic disorders. Exercise will help you get to sleep more easily and sleep more soundly. However, your body also releases cortisol during exercise, which may reduce your melatonin secretion. Exercise at least three hours before bed, and earlier if you can.14 |
Keep your room cool — The optimal temperature for sleeping is between 60 and 67 degrees Fahrenheit.15 If your room is cooler or warmer you may have a more restless night's sleep. Try to keep your thermostat set to the optimal sleep temperature for a better night’s sleep. |
Evaluate your mattress and pillow — You'll experience more restful sleep when your mattress and pillows are comfortable and supportive. You'll want to consider replacing your mattress after nine or 10 years, the average life expectancy of a good quality mattress.16 |
Downshift your mental gymnastics before bed — Put all your work away at least one, and preferably two, hours before bed. You need a chance to unwind before falling asleep without being anxious about the next day's plans or deadlines. Disconnect from any electronics, like the television or your phone, at least a half hour before bed.17 |
Avoid caffeine and alcohol before bed — Drinking alcohol and caffeine in the hours before you go to bed can prevent you from getting a good night’s sleep. If you need a nightcap, switch to a naturally caffeine-free herbal tea that also promotes relaxation, like chamomile or lavender. |