Seven hours of sleep keeps your brain intact

Adequate sleep keeps just may keep your brain from aging

How many z’s you get and the quality of them could be related to your brain’s health. Too much or too little sleep appears to have negative effects on concentration and memory.

New research reveals seven hours of sleep is what your brain needs for concentration and to hold those memories.

At the Alzheimer's Association International Conference® 2012 (AAIC® 2012) in Vancouver held yesterday, four studies suggest there is an association between sleep quality and quantity and the risk of cognitive decline, and that interventions to normalize sleep duration and correct sleep disorders may not only improve quality of life, but have potential to reduce or prevent cognitive decline, according to the AAIC press release.

An accumulation of evidence suggests that seven hours of sleep is recommended, but shorter than or longer than those seven hours may increase the risk for cardiovascular disease and type 2 diabetes. Now, four new studies take a look at sleep duration and influences on cognition among older adults.

In the first study which was one of the largest among the studies had evaluated data on 15,263 female participants of the Nurses’ Health Study. Research had indicate that those who had less sleep (5 hours or less) or more sleep (9 hours or more) had revealed lower mental functioning in comparison to participants that had seven hours of sleep.

Researchers had followed the women for fourteen years and had given three follow-up cognitive assessments biennially (occurring every two years).

Researchers had concluded that sleep durations that were shorter or longer than normal were associated to worse cognitive decline later on in life, consistent with findings for other chronic disease.

Elizabeth Devore, an associate epidemiologist at Brigham and Women's Hospital in Boston, author of study stated "I think this gives us data to think about sleep- and circadian-based interventions being a route to address cognitive function,” as reported by Health Day. Circadian rhythm is physical, mental and behavioral changes that follow a roughly 24-hour cycle, as noted by the National Institute of General Medical Sciences.

The second study conducted by the University of California, San Francisco. This study was led by Dr. Kristine Yaffe, MD, professor in the Departments of Psychiatry, Neurology and Epidemiology at UCSF. She is also Chief of Geriatric Psychiatry and Director of the Memory Disorders Clinic at the San Francisco VA Medical Center.

This study titled Sleep Disorders and Cognitive Function in Older Women, studied 1305 women, over the age of 75 with an average age of 83 years, who were enrolled in an ongoing prospective study and completed several days of wrist actigraphy and a subset with overnight polysomnography.

Researchers found sleep disturbances (sleep-disordered breathing or sleep apnea) had over twice the chance for developing mild cognitive impairment or dementia over a span of five years in comparison to those without sleep disturbances. Researchers note that their findings suggest that older adults be monitored for sleep disturbances and that interventions designed to improve sleep need to be investigated with particular attention to cognitive outcomes, according to the release.

The next study titled Sleep and Cognitive Decline in the Elderly: The French Three City Cohort, present by Dr. Claudine Berr, MD, PhD in epidemiology.

This study looked at almost 5,000 mentally healthy French people, aged 65 and over, and evaluated four times in a eight year period. Researchers had observed different aspects of insomnia and found that excessive daytime sleepiness (EDS) that had been reported by 17.9% of participants independently increase the risk for mental decline.

Researchers note their results show that EDS may be linked independently with the risk of cognitive decline in the elderly.

The last research noted comes from researchers at the Washington University School of Medicine, St. Louis, Missouri. The study titled Circadian Patterns of Beta-Amyloid in Human CSF and Plasma, presented by Dr. Yafei Huang MD, PhD.

Researchers had taken samples of blood and cerebrospinal fluid from three groups of volunteers; people with dementia, age-matched participants and younger participants, over 36 hours researchers found that daily sleep patterns were associated to levels of amyloid proteins (which are indicators of Alzheimer’s disease).

William Thies, PhD, Alzheimer's Association® chief medical and scientific officer stated in the release "We know that sleep patterns change as people age and that poor sleep affects overall health. What we don't know for certain is whether poor sleep has long-term consequences on cognitive function.”

In closing he adds "The studies presented today at AAIC suggest that cognitive health declines over the long term in some people with sleep problems. The good news is that tools already exist to monitor sleep duration and quality and to intervene to help return sleep patterns to normal. If we do this, there is the possibility that we may also help people preserve their cognitive health, but that needs to be tested.”

Numerous studies have been conducted on sleep patterns and cognitive function. These studies do not only apply to older adults but children as well.

In 2009, a study led by Dr. Naomi Friedman, PhD, senior research associate at the Institute for Behavioral Genetics at the University of Colorado at Boulder, had found that children who have sleep problems that remain through adolescences just may affect their cognitive ability later on in adolescences.

It appears that getting the right amount of sleep does matter when it comes to physical and mental health.