A cup of tea can do more than just warm you up and provide comfort.
According to a new systematic review of 33 different studies, including eight human intervention trials, drinking tea can help improve sleep quality and stress management.
The review found that several types of tea, including regular black tea, green tea, German Chamomile, Lavender, Rose, Jasmine and Passionflower, contain active compounds that can boost relaxation and reduce stress.
In particular, tea is a natural source of L-Theanine, an amino acid that has direct effects on the brain, helping to activate pathways that lower stress and create calm and relaxation.
Dr Tim Bond, a member of Tea Advisory Panel and author of the study, notes that at intakes as low as two cups a day, green tea, oolong, and the classic British "cuppa" have been shown to have an effect.
Dr Bond told The National: "Tea is the main natural source of L-theanine in our diet. Teas and herbal infusions also contain a range of polyphenols which act as anti-inflammatories and antioxidants which can contribute to good sleep.
"The flavonoid, apigenin, present in chamomile, is thought to be responsible for the sleep promoting effects of chamomile."
The study — commissioned by TAP and written by nutrition and well-being experts — also found that while herbal tea infusions are better known for their calming properties they can also lower stress and lead to better sleep.
It is no secret that getting a good night's sleep is essential to maintaining overall health and well-being.
According to studies from the UK, US, and Netherlands, one in four adults gets fewer than the recommended 7-9 hours of sleep per night.
Women over 40 are the worst affected, with the shortest sleep durations and poor sleep efficiency, while half of teenagers sleep less than the optimal 8-10 hours a night for their age group.
Drinking tea can help break the vicious cycle of stress and poor sleep, the review suggests.
Dr Bond said that a study of 18 young volunteers found that the aroma of black tea and Darjeeling tea, before consumption, helped in reducing stress and improving mood.
Drinking passionflower tea was found to improve sleep quality in a study of 41 adults, while two daily cups of matcha green tea significantly reduced anxiety levels in young adults.
"Six weeks of black (regular) tea lowered stress hormone levels and increased relaxation in a group of men asked to perform stressful mental tasks. Elderly adults drinking lavender tea twice daily had lower anxiety and depression levels," Dr Bond said
Poor sleep has been linked to an increased risk of type 2 diabetes, obesity, hypertension, depression and impaired immune function. It can also affect cognitive performance and impede decision-making.
Dr Gill Jenkins, a GP, warns about the health risks of getting too little high-quality sleep.
She notes that having less than six hours of sleep a night has been found to boost levels of C-reactive protein and increase markers of liver damage.
Incorporating two cups of tea into our evening routines could make a significant difference in our sleep quality and overall health, according to the review.
“Lifestyle changes including tea drinking and sleep hygiene can make a difference,” Dr Bond notes.
