Wellbeing

Sleep Cycle And Your Health

Doctors have warned for years that Americans are not getting enough sleep. Health consequences range from drowsy driving and irritability to an increased risk of dementia, heart disease, and early death.

Another study has suggested that one particular type of sleep may be especially important when it comes to how the brain responds to stressful situations.

The research found that people who spent more time in rapid-eye-movement (REM) sleep, which is the phase when dreaming occurs, had lower fear-related brain activity when they were given mild electric shocks the next day.

The findings hypothesized that getting sufficient REM sleep prior to fearful experiences may make a person less prone to developing a post-traumatic stress disorder

Sleep Schedule And Your Health

A new study suggests that when routine sleep habits are disrupted, that increases your risk for diabetes and heart disease.

The study found that those with large differences in their sleep schedules on workdays and free days tended to have worse cholesterol and fasting insulin levels, greater insulin resistance, larger waist size, and higher body mass index (BMI). The body mass index, BMI is an estimate of body fat based on height and weight.

 

The most basic daily rhythm we live by is the sleep-wake cycle, which is related to the cycle of the sun. It makes us feel sleepy as evening draws near and wakeful as the day sets in.

Sleep-wake and other daily patterns are part of our circadian rhythms, which are governed by the body’s internal or biological clock, found deep within the brain.

Research has been finding that the body’s clock is responsible for more than just sleep and wakefulness, as other systems, like hunger, mental alertness, and mood, stress, heart function, and immunity also operate on a daily pace.

Jet lag and shift work can throw our normal patterns out of whack and take a toll on our physical and mental health. Even shifting the clock an hour forward or backward when daylight savings time begins or ends can disrupt some people’s biological clocks.

There is the problem that a night-time schedule places you at greater risk of heart disease, diabetes, gastrointestinal illnesses and reproductive problem. For people whose body clocks are misaligned for many years, there is also the risk or higher rates of developing some cancers.

Unfortunately, nobody knows really why disrupting the dark-light, the sleep-wake cycle should have such an impact on our health. Though researchers are unpacking the problem little by little, there are still a lot of assumptions about circadian rhythms and body clocks and who knows what.

The idea of a biological clock may sound like a quaint metaphor, but there is actually a very distinct brain region that is charged with keeping time; an area called the suprachiasmatic nucleus (or SCN), situated right above the point in the brain where the optic nerve fibers cross.

This location enables the SCN to receive the cues it needs from light in the environment to help it maintain time.

Genes may influence the body’s clock and circadian rhythms since the system requires both types of input light and genes to keep it on track.

To stay on the 24-hour cycle, the brain needs the input of sunlight through the eyes to reset each day, and when humans are allowed to run off their body’s clock apart from input from the sun (by being kept in continuous darkness), the body’s daily cycle tends to lengthen to about 25 hours.

Also, when people lack the genes that help control the clock’s cycle, their sleep-wake cycles can stray even further, or be absent completely. The need for both light and genes, make the biological clock a good example of how genes and the environment work in harmony to keep the system functioning well.

Click here to read more about Sleep Cycle.

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