Sleep is the Preventive Medicine We All Need
In an age of countless supplements, workout programs and diets, it can be easy to overlook the importance of sleep. But when it comes to preventing disease, improving intellect and reducing stress – among many other positive effects – sleep is the preventive medicine we all need. A growing body of research points to sleep as the solution for problems from mental health and mood, to physical wellbeing and even heart health. In fact, poor sleep has been so strongly linked to cardiovascular disease that the American Heart Association recently added it to its checklist of modifiable risk factors for heart disease along with smoking, blood pressure, cholesterol and weight.
Researchers are still trying to understand exactly why we need sleep, but they have a few theories. One is that it evolved as a response to the increased risk of attack by predators at night. Another is that sleep helps the brain organise and consolidate memories. Another is that it provides time for the body to repair cells that are used or damaged during waking hours. The most likely explanation, however, is that sleep is simply a restful time when the body can prepare for action again.
A good night’s sleep gives you the energy you need to work, study, play and care for others. It is also important for your emotional well-being and for keeping your immune system strong, so that you can fight off infection and sickness. But most importantly, a good night’s sleep helps your brain and body function at their best.
If you don’t get enough sleep, you can experience a range of symptoms including difficulty concentrating and remembering details, irritability and trouble making decisions. Getting too little sleep can also make you feel stressed and increase your risk of high blood pressure, stroke and depression. The reason for this is that, when you don’t sleep properly, your body produces a hormone called cortisol. This is a natural defence against the effects of stress, but when it becomes a regular occurrence, your body can become over-reliant on it and start to respond negatively.
When you don’t get enough sleep, your body also struggles to maintain its normal metabolic processes. For example, a lack of sleep reduces the production of insulin, which regulates your blood sugar levels. This can lead to diabetes, obesity and other health problems.
Your body’s glymphatic system also clears waste out of the brain while you sleep. This is an essential part of healthy brain function, removing toxic byproducts that build up throughout the day and could cause damage. In addition, during deep sleep the brain’s remapping activity can help with memory and emotional processing. And the REM cycle is when we dream and it’s thought that this is where most of our memory consolidation takes place. It’s also where the connections we make between different events, feelings and sensory input are made. This is known as ‘executive function’, and it’s what improves with a good night’s sleep.