How many hours of sleep did you get last night? Scientists recommend a solid eight hours of sleep every night. However, as everyone knows, you can get by with much less sleep if needed. Or can you? Research on sleep has uncovered some pretty amazing (and likely frightening) facts about sleep and the lack of it.
The Power of Sleep
Sleep is far more powerful than most realize. A part of your brain called the hippocampus is responsible for your memory of learned things. During sleep, the cells in your hippocampus essentially hit the save button and then reset to take in more memories. The magic amount of sleep required for the maximum saving and resetting of your memory is eight hours. Any less and the ability to process new data greatly decreases.
An experiment had a large group of people sleep eight hours and another group was deprived of some sleep. Both groups were hooked up to MRI machines to measure activity in their hippocampus. Those who had less than eight hours of sleep had up to a 40% drop in memory-forming brain activity. It looks like cramming for that test is not as effective as you think because your brain cannot process the data.
No Back Up Plan
Your body is a powerhouse and it requires a reset every day in order to function properly. Sleep is not unique to humans. Every animal sleeps and they have forever. Remember, humans are animals–a fact that is often forgotten. What is also often forgotten is that most animals have been on Earth sleeping for a lot longer than our existence. What is unique to humans is our constant desire to cut short our sleep period. No other animal does so much to disrupt its sleep than the human animals.
This unique human feature has consequences. The millions of years of animal existence has allowed animals to evolve to become more and more complex and fit. The human animals are the most complex yet. Millions of years of evolution have allowed humans to overcome many adverse things that can happen in our environment.
If our body is invaded by harmful organisms, the body attacks them to keep us healthy. If you get injured your body has developed ways to heal the most common mishaps. However, sleep is different. Because no other animal before humans has ever tried to manipulate the natural sleep cycle, modern animals (including humans) have not developed a backup system for the required sleep.
Sleep studies have found that the decrease in memory making when you don’t sleep eight hours is the least of the problems. Scientists have discovered far more dangerous consequences associated with a lack of sleep.
If you experience a four-hour sleep night, your body’s immunity system decreases by 70%. That is a very significant number. Your immune system is responsible for fighting off everything from invading bacteria to viruses that cause the cold, flu and other problems that can make you sick. One study even found that those people who work the night shift have greater occurrences of cancer because of their sleep disruption. Another study found that reducing your sleep to six hours a night for just a week causes a significant number of cells to distort and mutate.
Other studies have found that even a one hour decrease or increase in sleep associated with daylight savings time can make a huge difference. The day after we lose an hour of sleep due to daylight savings time has a 24% increase in heart attacks. In the fall, when the change gives us an extra hour of sleep, there is a 21% decrease in heart attacks the next day. Sleep matters! A lack of sleep shortens your life.
The Good News
There is some really good news. Research shows that the absolute best thing you can do for your body is to get eight hours of sleep a night. A good night’s sleep is better than anything else you can do for your body and it doesn’t cost a thing. If you are having trouble sleeping, scientists say that you should go to bed and wake up at the same time every day and the temperature of your room should be a cool 65 degrees at night. Sleep tight and live long!
Mike Szydlowski is science coordinator for Columbia Public Schools.