What is the world’s favorite drink? As Emory students, it’s easy to say “Coke, obviously,” or my personal holy grail, coffee. Both answers are wrong. In fact, even fruit juice isn’t the correct answer here despite being loved by children and adults worldwide.
So what is the world’s favorite drink? The answer, shockingly, is tea.
Historically, tea has been the beverage that people go to for comfort, immunity, and warmth. First discovered by accident around 2732 B.C. by Emperor Shen Nung, tea has since grown from a simple Chinese medicine into a worldwide storm (The Origins and History of Tea | Where Did Tea Originate?, n.d.). By the ninth century, China had introduced the complex beverage to Japan and Tibet. Soon it took root in India as well as Russia.
Europeans were a bit slower to jump onto the tea train. The Dutch were the first Europeans to be recorded drinking tea, with the product’s first import arriving in the Netherlands in the 17th century. Even the British only caught wind of what was soon to be a staple in their country in 1650 (History of Tea – Learn About Tea History, n.d.).
Tea also made its debut in Africa during the 17th century (History of Tea – Learn About Tea History, n.d.). The first tea plant was planted in the Cape in 1687–but the drink did not progress until about the 19th century. Tea has since spread in Africa during the 20th century, notably in Kenya, Malawi, and Tanzania (The Origins and History of Tea | Where Did Tea Originate?, n.d.).
Since then, tea has become so popular around the world that there are now over three thousand types of tea today. The most widely consumed beverage in the world has both a historical and cultural importance that simply cannot be rivaled by any other beverage. However, it’s not just the cultural benefits that have kept this seemingly simple drink a fan favorite for so long. Tea offers many medicinal qualities that have fueled many ancient healing practices. So many medicinal qualities, in fact, that we’re still uncovering new ones. The drink is brimming with antioxidants, flavonoids, and other biologically active substances, such as polyphenols, theaflavins, caffeine, and theanine, which gives the tea its astringent and fresh taste. However, that is not the only purpose of those substances. Teas are also known to have effects on neurological function, and, as emerging studies show, neuroprotective effects that decrease the risk of getting neurodegenerative diseases such as Parkinson’s, Alzheimer’s, and general cognitive decline.
A new study led by the National University of Singapore, and published in Aging, shows evidence of the rise of both functional and structural neural connectivity in correlation to drinking tea. After conducting experiments with adults aged above sixty using magnetic resonance imaging (MRI) and neuropsychological testing, the researchers found that those who drank green tea, oolong tea, or black tea at least four times a week had brain regions that were interconnected in a more efficient way (Li et al., 2019).
“Our results offer the first evidence of the positive contribution of tea drinking to the brain structure, and suggest that drinking tea regularly has a protective effect against age-related decline in brain organization,” said Dr. Feng Lei, a researcher in the Department of Psychological Medicine at NSU (Li et al., 2019).
The research shows that tea opens up several pathways for the prevention of neurodegenerative diseases like the ones listed earlier. With the accelerated aging population in the world, the prevalence of neurodegenerative diseases such as Parkinson’s and Alzheimer’s are increasing over time reaching roughly 1.3 million people over the age of 65 in 2020. With this emerging research, however, there’s a chance that these diseases may be preventative for some time. In other words, there’s a chance they may be able to slow down significantly.
In this recent decade, many studies have proven that tea has neuroprotective functions. According to one Ohsaki Cohort Study, which spanned 5.7 years and involved more than thirteen thousand Japanese volunteers over the age of 65, green tea consumption significantly reduced the risk of dementia. Another study led by Shu-Qing Chen et.al. states that large amounts of evidence have indicated that tea polyphenols (reducing agents known to protect the body against oxidative stress) play a neuroprotective role in neurodegenerative diseases through antioxidation and the regulation of signaling pathways (Chen et al., 2018).
Even with all this, there is so much more to tea. Theanine is a unique amino acid of tea, accounting for 1–2% (dry weight) in fresh tea leaves. Numerous studies have shown that theanine has a neuroprotective effect. For example: glutamate is the most widely available excitatory amino acid in the central nervous system and involves many important physiological functions in the brain. When in a certain concentration, any neurons exposed to the glutamate will undergo cell death, as Kakuda and their colleagues found (Kakuda et al., 2008). However, if those neurons were pre-treated with theanine, the probability of cell death greatly decreased. Theanine, similar to glutamate in chemical structure, can compete for the binding site of glutamate and inhibit the death of neurons (Kakuda et al., 2008).
WORKS CITED
Chen, S., Wang, Z., Ma, Y., Zhang, W., Lu, J., Liang, Y., & Zheng, X. (2018b). Neuroprotective Effects and Mechanisms of Tea Bioactive Components in Neurodegenerative Diseases. Molecules, 23(3), 512. https://doi.org/10.3390/molecules23030512
History of Tea – Learn About Tea History. (n.d.). http://www.coffeeteawarehouse.com/tea-history.html
Kakuda, T., Hinoi, E., Abe, A., Nozawa, A., Ogura, M., & Yoneda, Y. (2008). Theanine, an ingredient of green tea, inhibits [3H]glutamine transport in neurons and astroglia in rat brain. Journal of Neuroscience Research, 86(8), 1846–1856. https://doi.org/10.1002/jnr.21637
Li, J., Romero-Garcia, R., Suckling, J., & Feng, L. (2019a). Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation. Aging, 11(11), 3876–3890. https://doi.org/10.18632/aging.102023
The Origins and History of Tea | Where Did Tea Originate? (n.d.). https://marktwendell.com/historyoftea
