I'd consider myself a pretty good sleeper. There are times when travel or stress can throw off my sleep schedule, but I generally have no problem rising early. I'm most productive in the morning, but I don't take any credit for that. It's in my DNA -- literally.
Genetics play a part in determining how we sleep and any sleep disorders we experience. You can always make positive changes to your sleep habits and schedule, your body will have innate preferences that can be hard to fight. So, next time you wish for a different sleep pattern, don't be so hard on yourself.
Below, I'll dig into how genetics influence our circadian rhythm and sleep disorders. For more, see the latest sleep hack people love, what natural sleep aids you should use instead of melatonin and how to determine your sleep language.
Your circadian rhythm
The circadian rhythm is the natural cycle of wakefulness and sleep, also called our internal clock. The circadian rhythm is involved in several functions, like body temperature and appetite. It can regulate our sleep thanks to the hormone melatonin and sunlight. When exposed to light, the melatonin production in the brain halts and we feel alert. Once it sets, melatonin floods the brain, and we get tired. This is how it's supposed to work, although technologies that give off blue light can warp our internal clock and compromise our sleep quality.
We all have internal clocks, but it doesn't mean they all operate on the same periods. There's a genetic factor to it.
Sleep chronotype
Night owls get a lot of flak because they stay up late and often have trouble getting up early for traditional school or work schedules. What if I told you that your genetics partly determine if you're a morning or night person? Sleep chronotypes are the natural disposition for sleep and wakefulness. You've probably heard of them referred to as an "early bird" or "night owl." Maybe you've even looked into the four animal chronotypes: bear, lion, wolf and dolphin.
Your chronotype can be influenced by factors like age, sex, environment and genetics. Research published in Nature Communications found that 351 genes are involved in determining your circadian rhythm.
Read more: Wake Up Earlier With These 9 Tips Backed by Science
Genetic predispositions aren't just limited to what type of chronotype you have. Specific gene mutations can result in sleep disorders of the circadian rhythm.
Short sleeper syndrome
Short sleeper syndrome is another example of a potential genetic predisposition for different sleep habits. A person with short sleeper syndrome requires less sleep than others and doesn't experience the negative effects of sleeping less than the recommended amount. Generally, they sleep for six hours or less with no brain fog or difficulty concentrating the next day because they are well-rested. Short sleeper syndrome occurs when the ADRB1 gene is mutated.
Delayed sleep phase syndrome
Another circadian rhythm-related sleep disorder with a genetic component is delayed sleep phase syndrome, also known as delayed sleep-wake phase disorder. This disorder is marked by sleep patterns that are delayed by two hours or more than typical sleep patterns. Unlike short sleeper syndrome, where people may choose to go to bed later because they need less sleep, those with delayed sleep phase syndrome need the recommended seven to nine hours of sleep. They just go to sleep later and wake up later than other people.
The gene PER3 has two genetic variants that influence what type of sleeper you are: a short allele and a long allele. A short PER3 allele has a strong association with delayed sleep phase syndrome. Longer alleles are linked to early risers.
Other sleep disorders
Sleep disorders also have a significant genetic component. For instance, some people are genetically more likely to develop insomnia than others. The University of Exeter Medical School has found 57 gene regions associated with insomnia. It's estimated that about a third of your risk for insomnia is genetic.
Remember, just because a genetic predisposition exists doesn't mean you'll experience it. Your chances are simply higher. Here are three sleep disorders that have DNA connections.
Obstructive sleep apnea
Obstructive sleep apnea is a common sleep disorder marked by loud snoring and frequent breathing interruptions that can sound like loud gasping. It happens because the muscles in the airway collapse in and cut off your ability to breathe momentarily. The amount of times this happens will vary by person.
It's estimated that your risk of developing OSA is 50% greater if you have first-degree relatives, like parents or siblings, with it. Contributing genetic factors include body weight, muscle control and facial anatomy. More research is needed to fully understand how genetics play into obstructive sleep apnea.
Restless legs syndrome
Restless legs syndrome is another sleep disorder with a genetic component. This neurological condition runs in families. Between 40% and 90% of people with RLS report having a first-degree relative with it. No causative genes have been found for RLS, but several genes, like PTPRD, MEIS1 and BTBD9, have been identified as increasing RLS risk.
Narcolepsy
Narcolepsy is a neurological disorder that impacts a person's ability to choose whether they're awake or asleep. People with narcolepsy often feel drowsy during the day, experience cataplexy or the temporary loss of muscle control and have sleep attacks in which they fall asleep without warning.
Narcolepsy is rare, but you're more likely to have narcolepsy if someone in your family has it. Research has also found that a variation in the HLA-DQB1 gene increases your likelihood of developing narcolepsy. Narcolepsy is more likely to develop because immune cells attack the neurons that secrete the hormone hypocretin.
Too long; didn't read?
Genetic predispositions are a big, complex topic that's still being researched. There's still a lot that we don't know. It's important to know that predispositions are just that; they don't mean you'll develop disorders like sleep apnea, narcolepsy or restless legs syndrome.
It also doesn't mean that night owls can't successfully sleep and function on an early morning schedule. It might just take a little extra attention. If you don't know where to start on your sleep journey, try doing these simple things tonight:
- Set a consistent bedtime
- Take a warm bath or shower about an hour before bed
- Integrate relaxing activities before bed, like reading or listening to music
- Add light yoga or meditation
- Stay off electronics before bed
- Stop drinking caffeine at least six hours before bed
It's important for us all to ensure that our sleep hygiene is strong and that our mattress suits our needs. You can sleep well, no matter what your DNA says.