The Stealthy Stimulant: Unpacking Tea's Impact on Sleep

Question: If I’m finding that my evening tea is still affecting my sleep, what’s a specific component of certain teas that might be contributing to that and what are some alternatives?

The Caffeine Conundrum

The ritual of an evening tea can be a soothing balm at the end of a long day. However, for some, this comforting habit may inadvertently be disrupting precious sleep. The primary biochemical component in many traditional teas that can interfere with rest is caffeine [2, 7]. Caffeine is a central nervous system stimulant, known for its ability to increase alertness and reduce fatigue. While beneficial during the day, its presence in an evening beverage can make it difficult to fall asleep or stay asleep [7]. This effect can vary significantly between individuals based on their sensitivity and metabolism.

Tea Varieties and Their Caffeine Content

The caffeine content in tea is not uniform; it depends heavily on the type of tea plant and how the leaves are processed. For instance, true teas, derived from the Camellia sinensis plant, naturally contain caffeine. This includes black tea, green tea, oolong tea, and white tea [8]. The processing methods, such as fermentation, can influence the final chemical profile, including volatile compounds and other nonvolatile components [3, 6]. While research often focuses on coffee’s caffeine content [1, 4], it’s crucial to remember that teas also harbor this stimulant, albeit often in lower concentrations than coffee. The amount of caffeine can also be influenced by factors like harvest season and cultivar [8].

Beyond Caffeine: Other Considerations

While caffeine is the most prevalent culprit, other factors in certain teas might subtly influence sleep. For example, some teas contain compounds that can affect mood or relaxation. However, the evidence strongly points to caffeine as the main perpetrator when sleep disturbance is noted [7]. The complexity of tea’s chemical makeup, including compounds like thearubigins and ester catechins, contributes to its diverse flavor profiles and potential physiological effects [3]. Yet, for those struggling with sleep, pinpointing caffeine is the most practical first step.

Embracing Caffeine-Free Alternatives

The good news is that a vast array of delightful beverages can offer the comfort of a warm evening drink without the sleep-disrupting effects of caffeine. Herbal teas, often referred to as tisanes, are derived from a wide range of botanicals, none of which are from the Camellia sinensis plant and therefore are naturally caffeine-free. Popular choices include chamomile, known for its calming properties, peppermint, which can aid digestion, and rooibos, a South African herb with a naturally sweet flavor. Other excellent options include ginger tea, hibiscus tea, and fruit-infused blends. These alternatives allow you to continue your evening ritual while prioritizing a restful night’s sleep. By making a conscious switch, you can enjoy the sensory pleasure of a warm beverage without the unwanted stimulant effects [7].

References

[1] — Ernesto Illy, Luciano Navarini — Neglected Food Bubbles: The Espresso Coffee Foam. — 2011-Sep — https://pubmed.ncbi.nlm.nih.gov/21892345/ [2] — Katarína Poláková, Alica Bobková, Alžbeta Demianová, Marek Bobko, Judita Lidiková, Lukáš Jurčaga, Ľubomír Belej, Andrea Mesárošová, Melina Korčok, Tomáš Tóth — Quality Attributes and Sensory Acceptance of Different Botanical Coffee Co-Products. — 2023-Jul-11 — https://pubmed.ncbi.nlm.nih.gov/37509767/ [3] — Qiuming Li, Qingcai Hu, Xiaoxi Ou, Jihang He, Xinru Yu, Yunzhi Hao, Yucheng Zheng, Yun Sun — Insights into “Yin Rhyme”: Analysis of nonvolatile components in Tieguanyin oolong tea during the manufacturing process. — 2024-Oct-30 — https://pubmed.ncbi.nlm.nih.gov/39253009/ [4] — Faguang Hu, Haohao Yu, Xingfei Fu, Zhongxian Li, Wenjiang Dong, Guiping Li, Yanan Li, Yaqi Li, Bingqing Qu, Xiaofei Bi — Characterization of volatile compounds and microbial diversity of Arabica coffee in honey processing method based on different mucilage retention treatments. — 2025-Jan — https://pubmed.ncbi.nlm.nih.gov/39974542/ [5] — Yuezhao Deng, Cheng Li, Yineng Chen, Zhuoyang Zou, Junyao Gong, Chengwen Shen, Kui Fang — Chemical Profile and Aroma Effects of Major Volatile Compounds in New Mulberry Leaf Fu Brick Tea and Traditional Fu Brick Tea. — 2024-Jun-08 — https://pubmed.ncbi.nlm.nih.gov/38928750/ [6] — Jianfeng Liang, Hailin Wu, Mingfei Lu, Ya Li — HS-SPME-GC-MS untargeted metabolomics reveals key volatile compound changes during Liupao tea fermentation. — 2024-Oct-30 — https://pubmed.ncbi.nlm.nih.gov/39280217/ [7] — Yuxin Fan, Yaonan Zhu, Yunyu Wang, Jun Jiang, Shaopeng Yang, Jie Lu, Qinghua Ma, Hong Zhu — Sleep quality mediates the association between tea consumption and duration of COVID-19-related symptoms in middle-aged and elderly adults (aged 50 and above). — 2025 — https://pubmed.ncbi.nlm.nih.gov/40881360/ [8] — Fan Huang, Haijun Wu, Fan Luo, Yingchun Wang, Yulong Ye, Yiyun Gong, Xianlin Ye — Effect of Harvest Seasons on Biochemical Components and Volatile Compounds in White Teas from Two Cultivars. — 2025-May-18 — https://pubmed.ncbi.nlm.nih.gov/40428574/