Sleep is a universal behavior observed across many species. While its exact functions are still being explored, it serves multiple vital roles. It offers a period for physiological restoration and rejuvenation, aids memory consolidation and learning, helps emotional regulation, and boosts immune function. Despite variations in sleep patterns and durations among different species, the commonality of sleep suggests it offers a range of evolutionary advantages critical for survival and well-being.
Insomnia is a prevalent sleep issue that can make it difficult to fall asleep, stay asleep, or cause you to wake up earlier than desired without returning to sleep. Despite spending time in bed, you may wake up feeling fatigued. Insomnia can affect your energy, mood, overall health, job performance, and quality of life. The amount of sleep an individual requires can differ, but adults generally need between seven and eight hours per night.
Many adults will eventually encounter short-term or acute insomnia, typically triggered by stress or a significant life event. This usually lasts for a few days to weeks. Others may experience chronic insomnia, which persists for a month or longer and could be a standalone issue or linked to other medical problems or medications.
Fortunately, enduring sleepless nights is not inevitable. Making simple adjustments to your daily routine can bring about improvements.
A 2020 meta-analysis of twin studies estimated the overall heritability of insomnia to be approximately 40%. According to a 2012 review of sleep disorders, 35% of people with insomnia have a positive family history, with the mother being the most commonly affected family member. Some of the most well-studied genes and polymorphisms related to insomnia are described below:
The serotonin transporter gene region, commonly known as 5-HTTLPR, is frequently studied in psychiatric genetics, including its relationship with insomnia.Â
5-HTTLPR is a genetic variant in the serotonin transporter gene, SLC6A4, also known as SERT. This gene is responsible for the reuptake of serotonin, a neurotransmitter that plays a significant role in mood regulation, among other functions. The 5-HTTLPR variant affects how efficiently serotonin is recycled back into nerve cells after release. This can influence an individual’s susceptibility to mood disorders like depression and anxiety.Â
Numerous studies have investigated the 5-HTTLPR polymorphism short and long-allele variants. Some research has also looked at sleep issues within the broader context of mental health disorders, finding noteworthy results.Â
A 2010 association study discovered that the short allele of the 5-HTTLPR was significantly more common in individuals with insomnia compared to the control group (47.1% vs. 39.9%)
Another cross-sectional study published a few years later found that each short (S) allele of 5-HTTLPR increased the risk of insomnia by over 80% and highlighted a significant interaction with job-related stress. In people with two short alleles (SS genotype), those experiencing high job-related stress had an elevated risk of insomnia, while those with low pressure had a reduced risk.Â
A 2014 review also emphasized the role of 5-HTTLPR in affecting sleep quality through stress reactivity mechanisms.
Adenosine, a substance that promotes sleep, starts at low levels in the morning and accumulates as the day progresses. Elevated adenosine levels and proper activation of its receptors are crucial for good sleep quality at night. Genetic variations that impair the function of adenosine receptors may be associated with insomnia associated with caffeine intake.
Among the four adenosine receptors (A1R, A2aR, A2bR, and A3R), A1R regulates the sleep-wake cycle, while A2aR plays a role in initiating sleep. The genetic variant rs5751876 within the A2aR is found to be associated with insomnia in connection to caffeine consumption.Â
A 2019 study showed that individuals with the rs5751876 T allele in the ADORA2A gene, which codes for the A2aR receptor, have a decreased risk of insomnia and general sleep complaints.
A 2016 study provided preliminary evidence for the potential role of the DRD4 VNTR polymorphism in daytime drowsiness. Another study identified a significant association between DAT1 rs464049 polymorphism and sleep duration in adults. Both DRD4 and DAT1 genes influence the dopaminergic system, a set of pathways that have been widely studied in relation to cognition, reward mechanisms, and motivation. Given the involvement of the dopaminergic system in sleep regulation, it has been cited as a potential target for future research. Recent research has also extended to other genes in the dopaminergic system, such as catecholamine-O-methyltransferase (COMT).Â
Other studies indicate the influence of the PGC-1α polymorphisms in an increased risk of insomnia. A 2012 study investigated how variations in PGC-1α might be related to insomnia among people with the Apoε4 risk allele – one of the most well-researched genetic links for Alzheimer’s disease. The study on 202 patients and 253 controls found that the GG allele of PGC-1α increased the risk of insomnia after controlling for sex, age, major depressive disorder, and Apoε4.
A 2014 study on middle-aged women examined polymorphisms in both AHR repressor (AHRR) and CLOCK genes, individually and in combination. Polymorphisms in both genes, AHRR (rs2292596) and CLOCK (rs1801260) were linked to reduced risk of insomnia, suggesting that they serve as protective factors. Women with homozygous or at least one AHRR G allele and CLOCK C allele had a reduced risk of insomnia compared to those homozygous for AHRR C and CLOCK T alleles.
Symptoms of insomnia can include:
If insomnia negatively affects your ability to function during the day, it’s advisable to consult a healthcare provider for a diagnosis and treatment plan. Should your physician suspect you have a sleep disorder, you may be referred to a specialized sleep center for additional tests.
Sleep is crucial for various aspects of human health and well-being, serving both physiological and psychological functions. Here are some reasons why sleep is important:
Given these multi-faceted benefits, it’s clear that sleep isn’t a luxury but a necessity for a healthy, fulfilling life.
Lack of sleep can have serious repercussions.Â
The human body alternates between two main types of sleep:Â
Differences in muscle activity, brain wave activity, and eye movement distinguish these phases and stages. Generally, the body goes through four to six full cycles of these stages each night, with each cycle lasting around 90 minutes on average.
Each stage is crucial in mental and physical restoration, contributing to overall well-being.
One simple yet effective step to enhance your sleep quality and set your body clock right is to reduce blue light exposure at night. Gadgets like phones, TVs, and LED bulbs emit blue light, affecting your natural sleep cycle and reducing melatonin production. You can wear blue-light-blocking glasses to minimize its effects. These glasses are designed to block 100% of blue light.
You can switch to color-changing or yellow-hued bulbs for nighttime use. Known as candlelight or Edison bulbs, these emit less blue light. Dimming your home’s overall lighting in the evening can help, too. Turn off bright overhead lights and use lamps fitted with these softer bulbs. It’s also a good idea to shut off your electronic devices a couple of hours before bedtime.
Your bedroom should be as dark as possible for optimal sleep. Even a tiny amount of light from street lamps can interfere with melatonin production. Consider installing blackout curtains or shades and covering up small lights on electronic devices to create a dark sleep environment.
Your body naturally expects cooler temperatures when it’s time to sleep. Maintain a cool but comfortable bedroom temperature for better sleep. Consider specialized water-cooled mattress toppers to help keep your bed cool.
Sleep is essential for everyone’s health and well-being. LifeDNA’s Sleep Report gives an insight into several traits that can help you optimize your sleep at night.
LifeDNA’s Sleep report covers an analysis of Insomnia and (9) other sleep-related traits. Get yours here.
LifeDNA’s Sleep report also covers an analysis of your natural Melatonin levels. Get yours here.
*Understanding your genetics can offer valuable insights into your well-being, but it is not deterministic. Your traits can be influenced by the complex interplay involving nature, lifestyle, family history, and others.
Our reports and suggestions do not diagnose or treat any health conditions or provide any medical advice. Consult with a healthcare professional before making any major lifestyle changes or if you have any other concerns about your results.
*Understanding your genetics can offer valuable insights into your well-being, but it is not deterministic. Your traits can be influenced by the complex interplay involving nature, lifestyle, family history, and others.
Our reports have not been evaluated by the Food and Drug Administration. The contents on our website and our reports are for informational purposes only, and are not intended to diagnose any medical condition, replace the advice of a healthcare professional, or provide any medical advice, diagnosis, or treatment. Consult with a healthcare professional before making any major lifestyle changes or if you have any other concerns about your results. The testimonials featured may have used more than one LifeDNA or LifeDNA vendors’ product or reports.
