A Good Night's Sleep

"Getting a good night's sleep is important at all stages of life, but particularly as we age."

"Finding ways to improve sleep for older people could be crucial to helping them maintain good mental health and well-being and avoiding cognitive decline, particularlyfor patients with psychiatric disorders and dementia."

Professor Barbara Sahakian, University of Cambridge 

"It is important to note that there will always be individual variation [n sleep needs], with some people needing a little less and some people needing more -- a range of between six and nine hours."

"As long as people are waking up feeling refreshed and able to cope with their day, they are probably getting the right amount."

Dr.Guy Meadows, co-founder, Sleep School

Age group	Recommended amount of sleep
Infants 4 months to 12 months	12 to 16 hours per 24 hours, including naps
1 to 2 years	11 to 14 hours per 24 hours, including naps
3 to 5 years	10 to 13 hours per 24 hours, including naps
6 to 12 years	9 to 12 hours per 24 hours
13 to 18 years	8 to 10 hours per 24 hours
Adults	7 or more hours a night          Mayo Clinic

"Compared to adults with 'normal' sleep duration, those who report short sleep appear more likely to develop obesity, diabetes, and cardiovascular disease."

"[Similarly, long sleepers] tend to have a greater risk of many of the same diseases -- both short and long sleep are somewhat associated with disorders of cognition."

"[When it comes to the benefits of seven hours] genetics influence sleep need. There is a very small number of people who are genetically short sleepers and need less than six hours' sleep per night."

"People with inflammatory disorders or mild infections might need more sleep to help regulate activity in the immune system."

"Your body clock is affected by when the sun comes up, so it's no surprise that people who live further from the equator have a shorter biological nighttime."

"Guidelines also recognize that sometimes a bit less or a bit more than these amounts is best."

Dr. Greg Potter, specialist in sleep and circadian rhythms

New research has come out of the University of Cambridge and Shanghai's Fudan University where the sleep habits of close to 500,000 adults between the ages of 38 and 73 were studied with participants asked about their sleep patterns, their mental health and well-being -- while taking part in a series of cognitive tests. About 40,000 of the study participants also took part in brain-imaging and the gathering of genetic data.

 

The study resulted in researchers concluding that both too much and alternatively insufficient sleep could cause mental health problems, along with "worse cognitive performance". Consistency was found to be important, to be as regular as possible in sustaining the same amount of sleep each night. One reason, the researchers feel, for the "brain fog" lack of sleep causes is the fact that slow-wave deep sleep is disrupted. A situation which may be responsible for blocking the brain from clearing out toxins.

 

The brain's "memory centre", the hippocampus, was also found to be affected by both an excess or a deficit of sleep. Scientists are still uncertain just why sleeping for too long causes an effect similar to not having sufficient sleep. According to Britain's National Health Service, as many as one in three people in the U.K. suffer from insomnia; middle-aged and elderly people the most affected. The recommendation out of the study was a solid seven hours of sleep each night is optimal for good health. 

 

A link between sleeping for too long and dementia in older people has been affirmed by recent studies. A drop in the hormones estrogen and melatonin may cause insomnia in some menopausal women, according to a number of studies."As people age, the body secretes less melatonin, which is normally produced in response to darkness that helps promote sleep by coordinating circadian rhythms", according to the Sleep Foundation.

"There are four stages of sleep that repeat throughout our sleep cycle each night and are vital for our physical and cognitive health."

"Three of those stages fall into a non-REM [non-rapid eye movement] phase, and one in a REM [rapid eye movement] phase."

"[Stage 1 is non-REM sleep] You're in a light sleep state and can be awoken very easily. Heartbeat, eye movements, and breathing slow and your muscles will begin to relax. This stage lasts roughly ten minutes."

"[Stage 2, non-REM sleep, means] You're still in a light sleep state. Your muscles become more relaxed. Bursts of brain wave activity might occur -- this stage lasts between 30 and 60 minutes."

"[Stage 3 means you're in a deep sleep.] Your heart rate and breathing will be at their slowest. This stage is extremely important for your immune health and energy and your muscles will begin to restore. It's usually difficult to be woken during this stage, which lasts between 20 and 40 minutes."

"[Stage 4 is REM sleep]. This usually occurs 90 minutes into your sleep cycle and is vital for memory consolidation. That's when dreaming occurs."

"In your 40s, new concerns about sleep can arise, including sleep apnea, decreased quality of sleep, feeling tired throughout the day, changes in hormones, and less production of melatonin."

"Elderly people tend to have a short sleep duration during the night, but strong inclinations for daytime naps. They primarily experience Stage 1 or Stage 2 light sleep and often lack Stage 3 deep sleep."

Dr.Verena Senn, Head of Sleep Research & Neurobiologist, Emma -- The Sleep Company