This post is co-authored by Urvi Shah and Emily Neer.
From iced tea on a sweltering summer day to hot tea when you’re sick, tea has an important place in the lives of many people. However, the benefits of tea, and more specifically the benefits of incorporating tea into daily life, are less well known. There are many different types of tea that offer a wide range of psychological benefits. When provided with the research, you can choose the teas that will offer the most improvements to your life. By the end of this post, we hope to have you swapping out your second cup of coffee or energy drink for a cup of tea.
First, it is important to know the main distinction among various types of teas. Teas are either caffeinated or herbal. Four main types of tea – green, black, oolong, and white – are caffeinated teas derived from the same plant, Camelia sinensis, with different methods of preparation. The distinctions between these types of tea are based on their level of oxidation, or how long the tea leaves are exposed to oxygen. Black tea is fully oxidized, oolong tea is partially oxidized, and green and white tea are unoxidized. In addition, white tea is made from leaf buds, while green, black, and oolong tea use the actual tea leaves (“Tea processing”, 2019).
Because all these teas come from the same plant, they contain two substances that interact to provide unique psychological benefits: caffeine and l-theanine. Alternatively, herbal teas consist of a wide range of plants derived from water infusions of each plant in which hot water is poured over dried flowers, herbs, fruits, or other parts of the plant. Herbal teas can have a range of benefits from stress relief to better sleep depending on the plant that is used (“What is Herbal Tea?”, 2015).
Green tea, black tea, white tea, and oolong tea boost cognitive performance and reduce stress. In cognitively healthy older adults, the consumption of green, oolong, or black tea was associated with improved long term memory (Xu et al., 2021). Furthermore, black tea has been shown to improve attention, as well as mood (Einöther and Martens, 2013). The benefits associated with these teas are thought in part to be caused by the main active ingredients, caffeine and l-theanine.
Caffeinated beverages, like coffee, prevent the natural decline of performance and alertness that occurs throughout the day (Hindmarch et al., 1998). Caffeinated teas improve attention similarly to coffee, but tea may be associated with fewer negative effects. Individuals who consumed tea throughout the day had lower subjective ratings of sleep disruptions than individuals who consumed coffee throughout the day (Hindmarch et al., 2000).
L-theanine, a less well known substance, has been shown to improve attention and reduce anxiety. Young adults who ingested l-theanine in amounts comparable to a cup of tea showed increases in brain activity related to attention (Nobre et al., 2008). Additionally, young adults who took l-theanine experienced lower levels of baseline anxiety (Lu et al., 2004).
Furthermore, the interaction of caffeine and l-theanine can be beneficial. Young adults that were given a combination of l-theanine and caffeine experienced better reaction times as well as lower subjective ratings of tiredness, mental fatigue, and headaches (Haskell et al., 2008). In addition, adults who received a dose of green tea extract, which contains caffeine, and a dose of l-theanine showed higher alertness three hours after their dose (Park et al., 2011). The active ingredients of green, black, white, and oolong tea show that drinking even one of these types of teas can lead to a wide range of benefits, including improved attention, mood, and sleep.
Herbal teas like chamomile, lavender, ginseng, and passionflower have been shown to reduce anxiety and depressive symptoms and to improve sleep. Chamomile tea helps adults with anxiety and depressive symptoms. Adults both with and without a depressive history who were given chamomile extract over a period of time experienced lower general depressive symptoms (Amsterdam et al., 2012). In addition, adults with generalized anxiety disorder who were given chamomile extract in an amount equivalent to three cups of tea experienced a reduction in symptoms and an improvement in general psychological wellbeing (Mao et al., 2016). Although these studies involve chamomile extract, it is likely that the benefits carry over when drinking chamomile in tea form.
Lavender tea helps with sleep. Postpartum women with poor sleep quality who drank a cup of lavender tea for two weeks reported lower subjective ratings of fatigue and depression as well as higher ratings of infant bondings. However, this effect did not persist after the women stopped drinking tea, suggesting that the consistent consumption of lavender tea can be beneficial (Chen & Chen, 2015).
Ginseng tea can improve symptoms related to depression and anxiety as it helps regulate stress hormones (Lee & Rhee, 2017). Passionflower, a less common tea, can also improve sleep as adults who drank a cup of this tea over a one week period reported higher subjective ratings of sleep quality (Ngan & Conduit, 2011).
Herbal teas offer many different benefits – and there are many more than the four listed here!
The benefits of tea go beyond what has been covered here, and can include physical benefits, such as pain relief or lowering blood pressure. And unlike other common drink options such as coffee or soda, there haven’t been many drawbacks found with drinking tea. Whether you need a little caffeine to boost your energy and focus your attention, or you just want to unwind after a stressful day, consider sitting down and enjoying a cup of tea. With all of these tea options, you will surely be able to find a favorite type that meets your needs!
Special thank you to Laura Copan for edits and feedback.
Cover photo by Joanna Kosinska via Unsplash.
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