Overview

What keeps you up late at night? Do you feel like stepping onto a battlefield every time you go to bed? Do you get up feeling tired and cranky? We tend to think that sleeping is a passive activity, however, appropriate sleep has a profound effect on mood, emotional state, memory and cognitive functions. According to the American Academy of Sleep Medicine and the Sleep Research Society, a person needs 7 to 9 hours of daily sleep to function normally. Unfortunately, our fast-paced lifestyle has made us prone to sleep disorders and to desperately seek a sleeping aid. Interestingly, a good hygiene sleep routine that includes tea, could improve your sleeping pattern. Tea is historically well known for its ability to improve sleep quality,  influencing different aspects of the process such as the time that takes you to fall asleep and the amount of hours you sleep. In this article, we will share the evidence of the effect of different types of tea on sleeping and relaxation. 

Importance of quality sleep 

Sleep is not only a switch-off period, it is a vital process related to our overall health and well-being. High-quality sleep provides numerous health benefits:

• Consolidates memories
• Enhances cognitive function
• Bolsters our immune system
• Regulates metabolic system
• Calms down the cardiovascular system

When sleeping, it is possible to identify two distinctive phases by measuring the electrical activity on the brain: the first phase called non-rapid eye movement (NREM) and the second phase called rapid eye movement (REM). Each of these stages provides different benefits to our body. NREM results in the conservation of brain energy and facilitates memory consolidation. The REM cycle, on the other hand, produces muscle relaxation, dreaming, and regulation of emotions. Healthy individuals usually experience several NREM and REM cycles during the night that last between 90 and 110 minutes. Sleep disruptions can interfere with the restorative function of the NREM and REM phases resulting in changes in mood and emotions, as well as impairments in attention, memory, and decision-making.¹

Benefits of bedtime teas

A common feature of bedtime teas is their ability to enhance relaxation and reduce stress. The presence of different compounds in tea and other herbal infusions is responsible for these effects. One of the biological mechanisms to induce relaxation is through the release of a neurotransmitter called gamma-aminobutyric acid (GABA). This neurotransmitter binds to specific receptors in the brain reducing hyperactivity associated with anxiety and stress.² 

For instance, L-theanine, an amino acid that provides the characteristic flavour of tea, has been shown to induce alpha waves in the brain which are known as an indicator of relaxation.³ Additionally, some fragrant compounds from oolong tea like cis-jasmone and methyl-jasmonate can bind to GABA receptors providing a tranquillising effect on the brain and increasing sleeping time.⁴ Finding ways to calm down your anxiety and stress prior to going to bed is key for a night of good quality sleep. Including a cup of tea in your sleeping hygiene routine could help you make that final step into bed. 

Key ingredients in bedtime teas

When faced with a sleep disorder, a conventional treatment is to rely on pharmacological treatment to induce or prolong sleep. However, drugs could have a low impact on the quality of sleep, generate psychological dependence or provoke withdrawal effects of short or long-lasting duration. Bedtime teas, on the other hand, could be a non-pharmacological option that helps you relax and rest for better sleep without the side effects of drugs.

Chamomile 

Chamomile is a herb that belongs to the same family as daisies and sunflowers. Matricaria chamomilla (German chamomile) and Roman chamomile (Chamaemelum nobile) are the most well-known species and cultivated medicinal plants. Traditionally it has been used as a mild sedative (calming effect) to reduce anxiety. The tranquillisation sensation of chamomile may be due to the presence of apigenin, a compound that binds to the same receptors as GABA.⁵

Studies on the effect of chamomile tea on sleep quality have been conducted in subjects with serious sleeping disorders. For instance, the lifestyle of postpartum women really reduces their sleeping time and efficiency. A study conducted in Taiwan with this population for 6 weeks, showed that drinking one cup of chamomile tea per day improved postpartum depression and physical symptoms related to sleep inefficiency.⁶     

The effect of chamomile extract has also been studied in other mental health conditions that affect sleep latency and quality such as general anxiety disorders and depression.⁷ Subjects with anxiety and depression disorders, who took 1500 mg of chamomile extract for 8 weeks, reduced anxiety levels and depressive symptoms.⁸ These findings show that chamomile tea or extracts could improve the sleeping pattern in different health conditions. 

Lavender 

Lavender is called “the broom of the brain” in many oriental traditional medicines. Lavandula angustifolia is the most studied species in medical science. Lavender can be used in two different ways: lavender tea or lavender aromatherapy.  The mechanism by which it induces sleep is still unknown and the main active ingredients like linalool and linalyl acetate could be responsible for the sedative effect. 

Clinical studies in aromatherapy are relatively a new phenomenon. Different reviews on the topic found that lavender inhalation through diffusers or by adding oil drops on a pillow has a small to moderate effect on the improvement of the sleeping pattern.⁹ Adverse reactions of lavender oil inhalation including dizziness or mild headaches, are rare.¹⁰   

The intake of lavender tea could improve sleep quality as well. In a study conducted on elderly adults with sleeping disorders, it was shown that the intake of 2g of lavender flowers in tea bags for 3 months was able to improve the sleeping quality in this population.¹¹ Therefore, you can include lavender in your bedtime routine by drinking tea or inhaling its soothing fragrance for relaxation.

Valerian root 

Valeriana officinalis, also known as valerian root, is a herb native to Europe and some parts of Asia. The section of the plant that is used to prepare tea is the dried root or rhizome. Several studies investigating the effect of valerian extracts and dried roots on sleep quality and duration suggest that it enhances sleep without significant side effects.¹² In animal models, studies have shown that high doses of valerian extract enhance both the quantity and quality of sleep through the GABAergic pathway.¹³ Even though more studies in humans are needed to evaluate the effect of valerian root tea on sleeping patterns, research suggests that a positive impact on sleep quality exists. 

Lemon balm 

Melissa officinalis is a lemon-scented herb known as the common lemon balm. In Asian traditional medicine, it has been widely used to treat many mental disorders, such as depression, anxiety, insomnia, and stress.¹⁴ Lemon balm leaves are rich in phenolic acids and flavonoids that could bind to specific receptors in the brain inducing sedation and sleep enhancement.¹⁵ 

Little clinical studies have been conducted on the use of lemon balm as tea but it has been explored in other forms, such as essential oils and nutraceuticals. Further research and clinical trials are warranted to better understand the mechanisms underlying the effects of lemon balm tea on sleep and to establish optimal dosages for therapeutic use.

Passionflower 

There is a reason why passionflower is present in so many sleep supplements and herbal medicines. It is a popular sleep aid used for the treatment of sleep disturbances. It is scientifically known as Passiflora incarnata and has been studied for its potential effects on sleep. In a 2011 study, 40 participants reported better sleep quality after drinking a cup of passionflower tea for 1 week compared to the placebo.¹⁶ In another clinical study, it showed a positive impact on sleep patterns and improved sleep quality in individuals with insomnia disorders.¹⁷ Passionflower may offer promising benefits for individuals struggling with sleep problems, including insomnia.

Tea

The effect of tea on sleep and relaxation created controversial results due to the presence of caffeine. Two active ingredients with opposite effects coexist in tea, caffeine and L-theanine. Caffeine, especially from coffee, prolongs sleep latency, reduces total sleep time and sleep efficiency, and worsens perceived sleep quality.¹⁸ L-theanine on the other hand, is an aminoacid present in tea plants and could be responsible for providing the tranquilising effect of tea along with the presence of other substances such as polyphenols. In experimental studies, L-theanine could counteract the stimulatory effect of caffeine by facilitating a relaxed yet mentally alert state.¹⁹ 

Research on how tea affects relaxation and sleep is still developing. However, a study involving 20 middle-aged men found that drinking low-caffeine green tea reduced stress and improved sleep quality.²⁰ If you enjoy a warm beverage before bedtime, consider opting for low-caffeine teas or herbal infusions to help enhance your sleep.

Summary

We all cherish the days when we manage to get quality sleep. Proper sleep not only helps us handle daily stress but also boosts our immune system. Sleep consists of two main cycles: non-REM and REM stages. When these cycles are disrupted, our mood can suffer, leaving us tired and unfocused. Incorporating various teas and herbal infusions into our bedtime routine may help improve our sleep patterns. This is because certain compounds in these teas are believed to enhance the release of gamma-aminobutyric acid (GABA), which binds to brain receptors and promotes relaxation. Including a cup of tea in your bedtime routine could significantly improve your sleep quality.