How Too Much Sleep Harms Your Health
The link between sleep deprivation and an
increased risk of dementia is well documented. Now, a Japanese study has
discovered that the opposite may also be true, meaning that sleeping
for too long may also increase your risk of dementia, cognitive decline
or even an early death.
Researchers from Kyushu University recorded
the sleeping habits of 1,517 adults aged over 60 for a period of more
than ten 10 years. None of the volunteers had any indication of
cognitive impairment before the study commenced.
The team learned that people who slept for 10 or more hours a day more
than doubled their risk of dementia or a premature death, in comparison
with those who slept between five and 6.9 hours each day. They also
found that this increased risk is approximately equal to those people
who slept less than 5 hours a night.
While the researchers found that the
results were the same for participants of all ages and genders, they
could not determine what exactly caused the heightened risk. However,
their findings seem to point towards two distinct possibilities that
merit further research.
Poor sleep quality, the researchers noted,
can cause a protein called amyloid to accumulate in the brain, and this
is one of the chemicals that is most commonly associated with the
development of Alzheimer’s disease. This is because sleep is one of the
primary ways that amyloid is removed from the body.
The team also found that sleep disturbances may cause low-grade
inflammation to take place in the brain, and this is something that has
been connected to diabetes, depression, cancer, and other afflictions.
These, in turn, are all proven risk factors for dementia or a decreased
lifespan, and all of these risks become more serious as you age.
As people grow older, they are more likely
to experience disturbances in their sleeping patterns, according to
geriatric sleep researcher Constance Fung, an associate professor of
medicine at the David Geffen School of Medicine at UCLA. Aging often
also cause changes to the body's circadian system, also known as the
biological clock, which can contribute to memory loss.
There are also other available studies which have discovered links
between dementia and sleeping too little or too much. One study found
that sleeping for longer than 9 hours a night could be an early sign of
Alzheimer’s or dementia. According to Fung, one explanation might be
that inflammation, a core part of dementia, leads to increased
drowsiness and sleeping longer.
Although the Japanese study discussed above
did not establish why too much sleep is connected to an increased risk
of dementia and premature death, the team did suggest a few lifestyle
changes which could be helpful in minimizing the danger.
First of all, you need to get a moderate amount of exercise. According
to the study's findings, a low level of physical activity is connected
to an increased risk of premature death and cognitive decline, both
among those who slept too little, as well as for those who slept too
much.
High levels of physical exertion also lowered the risks of both early
death and dementia among those who slept for less than 5 hours a night.
Among those who slept over ten hours though, high physical exertion
didn’t end up lowering the risk of dementia, although it did appear to
erase the heightened risk of an early death.
According to the Centers for Disease
Control and Prevention, we should strive for 150 minutes of moderate
exercise per week. Examples of suitable activities include cycling,
walking briskly, gardening, water aerobics, or even ballroom dancing.
Another change recommended by the authors of the Japanese study is to
only use sleeping pills (or similar types of medication) as a final
resort. This is because they found that the participants who made use of
them were 66% more likely to develop dementia and 83% more likely to
die early compared to those participants who did not, regardless of the
amount of sleep they got each night.
In order to try and get a healthy 5 to 8 hours of sleep a night without
resorting to drugs, most professionals recommend maintaining a sleep
routine, such as by going to bed and waking up around the same time each
day. The American Sleep Association also recommends avoiding naps and
exercising regularly before 2 p.m.