Our brain is our biggest asset, it enables us to think, feel and analyse, it controls all our body functions and it even has its own clock. We’ve already discussed the importance of looking after our brain in a different post:
The best way to take care of your brain is to allow it a good night sleep. We are all somewhat aware how important the sleep is for us, however quite often we ignore it and carry on with our routines. By doing it we are robbing our bodies of the great benefits that a good sleep brings. Despite of a sleeping person looking quite peaceful (in most cases), there are a lot of activities occurring during our sleep, so it is not at all a passive exercise. It is recommended to get around 7.5 to 9 hours of uninterrupted sleep for an adult, to have the body and mind rejuvenated for the next day. If our sleep is cut short, the body doesn’t have time to complete all of the phases needed for various tasks including muscle, bones and nerve repair, memory consolidation, new cell growth or hormones release.
Normally, our sleep consist of five stages, recurring during so called ‘sleep cycles’ lasting about 90-110 minutes. Sleep cycles change during the night, and during a person’s lifetime. As we begin to fall asleep, we enter NREM (non-rapid eye movement) sleep, which is composed of stages 1-4. This accounts for about 75% of the night. Stage 1 is a light sleep and by stage 2 we become disengaged from surroundings, our breathing and heart rate regulates and our body temperature drops. Stages 3 and 4 are regarded as deepest and the most restorative phases during which the blood supply to the muscles increases, the energy is restored, the cell and tissue repairs and growth occurs, the hormones are released, while blood pressure drops, breathing becomes slower and the muscles relax.
The REM (rapid eye movement) first occurs about 90 minutes after falling asleep and recurs approximately every 90 minutes. During this stage the brain is active, so normally most of our dreams occur and recent memories may be consolidated, while our muscles are very relaxed and body immobile. It provides energy to our brain and body which supports daytime performance.
In our first sleep cycle during the night stages 3 and 4 are long, but the REM phase is short. Gradually 3 and 4 shorten while REM lengthens. By the morning, most of our sleep consists of stages 1, 2 and REM.
The benefits of good-night sleep:
– Enhances regeneration: during the sleep our body will aim to repair damage caused by stress, ultraviolet rays and other harmful factors, as well as eliminate toxins. Our cells normally produce more protein while the body is asleep. These protein molecules form the building blocks for our cells, enabling them to repair damage;
– Reduces stress: not getting enough sleep causes the body to go into a state of stress, when the body’s functions are put on high alert which causes an increase in blood pressure and a production of stress hormones. The stress hormones also make it harder for us to sleep;
– Keeps healthy heart: lack of sleep has been associated with worsening of blood pressure and cholesterol, the most common risk factors for heart disease and stroke;
– Helps prevent cancer: light exposure reduces the level of melatonin, a hormone that makes us sleepy and is thought to protect against cancer. Melatonin appears to suppress the growth of tumors. People who are exposed to light at night (e.g. by working night shift) have a higher risk for breast and colon cancer which has been linked to a differing levels of melatonin;
– Reduces inflammation: the increase in stress hormones raises the level of inflammation in our bodies, also creating more risk for heart-related conditions, as well as cancer and diabetes;
– Reduces depression: sleep affect many of the chemicals in our body, including serotonin. Deficiency in serotonin has been linked to depression;
– Memory boost: our dreams and deep sleep are an important time for our brains to make memories and links. While our body is resting, our brain is busy processing our day or past, making connections between events, sensory input, feelings and memories. This process is called memory consolidation;
– Increases alertness: a proper uninterrupted sleep makes us feel energised and alert the following day. The more active we are during the day, our chances of getting a good sleep are increased. Napping also improves memory, cognitive function and mood;
– Supports weight loss: not getting enough sleep impacts the balance of hormones in the body that affect appetite. The hormones ghrelin and leptin, responsible for the regulation of appetite, are disrupted by the lack of sleep;
Most common sleep problems could be linked to physiological or other disorders, including stress, brain and nervous system diseases, metabolic imbalance, cardiovascular conditions (MI, stroke, hypertension) and various pain-causing illnesses. Other factors include environmental conditions, alcohol and caffeine intake, mental or physical exercise too close to the bedtime.
Some of the issues caused by the lack of sleep were covered in one of the recent BBC articles:
So… Good night… until next time 🙂