How seasons affect our sleep
We sleep differently in summer than we do in winter, and the biggest reason for that is ambient light. Many of us tend to wake earlier in summer because the sun rises earlier too, but that often means we don’t feel tired, since natural light supresses the secretion of sleep-inducing melatonin. If you’re keen to maintain a regular sleep pattern, then black out blinds and curtains, or an eye mask, are a good idea but be aware, they can also turn people into a crutch. People with insomnia become very dependent on the rituals around going to sleep, which – paradoxically – can reduce your chance of natural sleep, because you can become so anxious about maintaining the rituals.
How much sleep do you really need?
Although conventional wisdom tells us we need eight hours a night, that doesn’t apply to everyone, as the amount of sleep you need depends on the individual. The key is how refreshed you feel when you’re awake, which is influenced by the different types of sleep you get: about 75% should be non-REM sleep (the start of the sleep cycle), and 25% rapid eye movement (REM) sleep (usually when you dream). The brain allocates the correct proportions in the amounts you need, and if you wake up feeling refreshed, then you are getting enough. New research suggests that the optimum number of hours is seven. The American Academy of Sleep Medicine (AASM) analysed sleep-time data, and concluded that if you get less than seven hours on a regular basis, you could be more at risk of hypertension, diabetes, high blood pressure, stroke, and cardiovascular and metabolic disorders.
The Art of the Power Nap
For a quick boost in alertness, the optimum time for a nap is 20 minutes. Its best to nap sitting upright in a chair as this will help you avoid falling into deep sleep. If you find yourself dreaming during your nap, this could mean that you are sleep deprived.
Sleep and the Brain: Can it affect Alzheimer’s?
Recent US research has suggested that poor sleep quality could be linked to Alzheimer’s. However, it was a small study by the University of California, involving 26 older adults with no cognitive impairment, and found a connection between the increase of protein plaques in the brain, poor sleep quality, and a difficulty in the laying down of memory overnight. This could potentially lead to Alzheimer’s since its related to the build-up of plaques. Although most people develop plaques as they age, those with Alzheimer’s tend to develop far more.