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Sleep genes: Heredity plans bigger role in need for sleep

Woman and alarm clock in bed

Thanks Mom and Dad.

Recent genetic studies suggest the early-riser or "don't talk to me before noon" mentality is heredity, according to the National Center for Biotechnology Information and U.S. National Library of Medicine.

Brain-specific markers called "human clock genes" affect when a person is awake and asleep through intricate, well-timed body functions that signal time for rest or work.

"For many years, we compared the morning larks and the night owls," says Dr. Seema Khosla, chief medical officer at North Dakota Sleep Center. "Just between these two sets we really see a difference in melatonin levels and body temperatures, depending on the time of day."

When looking at biology, people sit on a bell-curve of "morningness and eveningness," with 10 percent being true morning larks and 20 percent considered as night owls, according to Theconversation.com.

"We used to always think it was bad habits — some people stay up late because they're watching TV," Khosla says. "But part of the reason may actually be our genes. These genes, our body temperatures and certain hormone releases, like melatonin, create a beautiful concert of when everything is supposed to happen."

Sleep signals: Clock genes, body temperature

No matter how much we fight it with loud music and caffeine, several sleep signals prepare us for rest whether we are receiving them with open arms or barring our brains from the inevitable bedtime break.

Human clock genes — often called circadian clocks — are influenced by both psychological and physiological factors like body temperature, food intake, cognitive performance and mood. The coordinated activity by these millions of cellular clocks and oscillators create daily, monthly and seasonal rhythms according to U.S. National Library of Medicine.

To cue sleep, a person's core body temperature falls between 1 to 2 degrees. The temperature of both the brain and body decrease during NREM sleep, the cycle before the deepest sleep cycle (REM). According to Tuck.com, the average adult's core temperature reaches its lowest at about 5 a.m. before increasing to alert wakefulness.

Society is sleep's stumbling block

Our genes are not only the culprit when it comes to adhering to our natural sleep cycle; most of the time people can't get enough sleep because their tendency to bear a badge of busyness.

"It's like this honor that we get by on 4 hours or less," Khosla says. "We are all guilty of it."

Khosla says most people underestimate how much sleep they need: seven to nine hours is suggested for adults.

"We're not really great at figuring out when we are chronically sleep deprived," she says. "And we need to be more mindful of when we're consistently getting a little bit less sleep than our body needs."

When Khosla considers each person's sleep health now, she asks herself: If the person followed their natural rhythm, could their life change for the better?

"In years past, studies suggested if you were a morning lark you would have all these positive qualities," she says. "But then a evening person would be labeled as a scrooge or cranky."

In the past night owls may have been unfairly judged as most often these people have to ignore their signals to follow a work or school schedule. Khosla observed this through a patient who constantly struggled during high school and college.

"He always felt behind and didn't have much fun because he couldn't sleep," she says. "Now he has a job where he works at night and he feels so much better. Just this little change helped him get enough sleep so he can do what he wants."

5 questions for sleep deprivation

Khlosa instructs others to answer these five questions to consider if they're chronically sleep deprived.

• Do you need an alarm to wake up?

• Do you feel rested once awakened?

• Do you nod off during the afternoon?

• Are you fighting to stay asleep at night?

• Do you utilize a large amount of caffeine?

Additional factors like activity level, recent travel or a chronic illness affects a person's current sleep needs.

"Our sleep need is different from one person to the next," she says. "But even within that

same person their sleep needs change."

Discovering your chronotype

Michael Breus' book "The Power of When" discusses chronotypes — a person's natural inclination for sleep and the time of day when they feel most alert.

"Up until recently, it has always been two types — morning larks and night owls — but it's intriguing how Michael Breus is introducing four types: the Lion, Bear, Wolf and Dolphin," Khosla says.

A vocal proponent of sleep health, Breus uses the four chronotypes to illustrate how a person may capitalize on their natural rhythm and find the best times to eat, exercise and work.

• Lion: Traditionally called morning larks, these early-risers do their best work between 10 a.m. and 12 p.m. but usually crash an hour or two after lunch. Lions also tend to get hungry earlier, so they should eat as close to noon as possible. To fend off a crash, Breus' also recommends a short walk and exposure to sunlight.

• Bear: These people rise and set with the sun — literally. Bears usually sleep eight hours and may take a couple of hours to feel awake. Breus' recommends a hearty breakfast around 7:30 a.m.

• Wolf: Sometimes known as night owls, these people usually don't sleep until midnight or later and are most alert after the sunset. Wolves have trouble waking up before 9 a.m. but Breus' recommends holding off on the coffee until 11 a.m., if possible. This way, natural wake-up hormones can do their job before ingesting additional additives.

• Dolphin: People who are light sleepers and wake early but not refreshed are called Dolphins. These people often experience insomnia or irregular sleep cycles. Although groggy in the morning, Breus' recommends early exercise.

A quiz at Thepowerofwhen.com helps to define chronotypes according to Breus' research. Although Khosla can't comment on the validly of dividing chronotypes into four archetypes yet, she knows people's lives improve when they embrace their natural rhythm, rather than fighting it.

April Knutson

April Knutson is lifestyle-focused journalist producing stories for the Forum News Service about people, health, community issues, and services. She earned her degree in both English Literature and Mass Communications. After working as a digital marketing specialist and web design consultant for a few years, she joined Forum Communications in 2015. She grew up on a farm near Volga, S.D. Follow her on Twitter @april_knutson.

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