Chemical Comfort: The Many Health Benefits of Tea

Tea has been valued for its health benefits for centuries, and modern research supports its positive impact on well-being. As one of the most widely consumed drinks globally, let’s talk about what your body gains from drinking tea.

By Julieta Asenjo

Takeaways

• Tea supports both mental and physical wellness.

• Different tea varieties target distinct health concerns.

• Herbal teas are great natural medicines.

• Preparation methods influence tea’s health potential.

Introduction: A Brief History of Tea

The tea plant has been cultivated for millennia, and its leaves have been used in medicine and mindful practice throughout history. Ancient Chinese doctors prescribed it for digestion and clarity, while Japanese monks incorporated its preparation into meditation. The very act of brewing tea became a ceremonial tradition across Asia. Modern science confirms tea's medicinal compounds work in harmony with its ritualistic benefits. This unique combination of biochemical healing paired with sensible preparation makes tea unlike any other remedy in history.

The Chemistry of Tea and Your Body

There is growing evidence that regular tea consumption is associated with a lower risk of cardiovascular disease, neurological disorders, and metabolic syndrome. Tea's pharmacological effects stem from its complex phytochemistry. When you brew tea, the hot water activates a range of bioactive compounds (natural chemicals) in the leaves, sparking chemical reactions that produce health-boosting molecules. These molecules interact with your body at the cellular level: reducing inflammation, neutralizing harmful free radicals, and balancing neurotransmitters. All these benefits come from the tiny chemical changes happening within every sip.

All true teas (green, black, white, yellow, oolong, and dark) originate from the same plant, Camellia sinensis. What makes them different is how they’re processed, which alters their chemical profiles. Each tea contains various bioactive compounds contributing to its flavor, aroma, and health benefits.

Image: ScienceDirect

These compounds can be grouped into several key categories:

• Polyphenols: Antioxidants that protect cells from damage and may reduce disease risk.

• Alkaloids: Stimulants that boost alertness and energy.

• Amino Acids: Promote relaxation and mental clarity without drowsiness.

The table below highlights these compounds, their primary tea sources, and how they may benefit the body.

Chemical Compound	Type of Compound	Primary Tea Source	Effects on the Body
Epigallocatechin gallate (EGCG)	Polyphenol (Catechin)	Green tea, white tea, yellow tea	Powerful antioxidant, boosts metabolism, may lower cancer risk
L-theanine	Amino acid	All true teas (highest in green tea)	Promotes relaxation without drowsiness, enhances focus
Caffeine	Alkaloid (Methylxanthine)	All true teas (highest in black tea)	Increases alertness, improves concentration
Theaflavins	Polyphenol	Black tea, oolong tea	Supports heart and gut health, anti-inflammatory
Thearubigins	Polyphenol	Black tea	Antioxidant, contributes to dark color
Theabrownins	Polyphenol	Dark tea	May lower cholesterol, aids digestion

How Tea Compounds Support Your Health

Catechins and Epigallocatechin Gallate (EGCG) in Green Tea

 

Green tea is rich in natural compounds called catechins, with the most important one being Epigallocatechin Gallate (EGCG). This single compound makes up about 50–80% of green tea’s total polyphenols. EGCG acts as a strong antioxidant by donating electrons (tiny charged particles) to neutralize reactive oxygen species (unstable molecules that can harm the body). This prevents damage to important parts of cells like lipids, proteins, and DNA. Beyond protecting cells, EGCG also helps your body manage energy. It activates an enzyme called AMP-activated protein kinase (AMPK), which plays a role in helping your body absorb sugar and burn fat for energy. This is one reason EGCG is linked to benefits like weight management and improved metabolism.

EGCG doesn't stop there, it also offers brain protection. Studies show that it prevents amyloid-beta peptides, which are associated with Alzheimer’s disease, from forming toxic plaques that damage brain cells. A 2019 clinical study published in Aging showed that regular green tea drinkers had improved brain connectivity in the dorsolateral prefrontal cortex, a region critical for working memory and problem-solving.

The benefits of EGCG extend to cancer prevention as well. Research has found that EGCG can hinder cancer cell growth, promote the natural death of damaged cells, and reduce the spread of cancer to other parts of the body. Consistent green tea consumption has been shown to lower the risk of certain cancers, including breast, lung, and colorectal cancers.

Theaflavins and Thearubigins in Black Tea

In black tea, the oxidation of tea leaves turns simple catechins into theaflavins and thearubigins. These compounds give black tea its signature dark color and bold taste, but they also support heart and gut health.

Theaflavins help improve the function of blood vessels by increasing nitric oxide production, which helps widen blood vessels and improve blood flow. A 2023 study published in Frontiers in Nutrition found that participants who drank three cups of black tea daily had a reduction in both systolic (−2.6 mmHg) and diastolic (−2.2 mmHg) blood pressure. Even a small drop in blood pressure like this can reduce the risk of stroke-related deaths by 7%.

In terms of gut health, theaflavins in black tea aren't fully digested in the stomach and instead reach the colon, where they help grow beneficial bacteria. These bacteria break down theaflavins into short-chain fatty acids like butyrate, which give energy to colon cells and help keep the gut lining strong and healthy.

L-theanine and Caffeine

All Camellia sinensis teas contain both caffeine and L-theanine, a compound that affects brain signaling. While caffeine boosts alertness by blocking adenosine (a chemical that makes you feel sleepy), L-theanine works in a different way. It crosses the blood-brain barrier and binds to receptors that help control excitatory brain signals, reducing overstimulation without making you drowsy. It also raises levels of gamma-aminobutyric acid (GABA), a calming brain chemical that slows down activity and promotes relaxation.

When L-theanine and caffeine are combined, L-theanine helps balance caffeine’s effects, reducing jitteriness and creating a calm, focused feeling—a phenomenon quantified in a 2010 Nutritional Neuroscience study where participants who consumed both L-theanine and caffeine showed improved focus and felt more alert, along with a noticeable reduction in cardiovascular stress.

Theabrownins in Dark Teas

Dark tea gets its unique flavor, deep color, and health benefits from a special fermentation process where microbes break down the tea leaves. One popular type is Pu-erh tea, which is aged to develop an earthy taste. During this fermentation, compounds like theabrownins are formed, which, in animal studies, have shown the potential to lower cholesterol and triglycerides by influencing gut bacteria and bile acid metabolism.

For instance, in a 2024 study published in Food Science and Human Wellness, researchers found that Pu-erh tea helped lower unhealthy cholesterol levels in the liver of mice with colitis (a type of gut inflammation). The researchers believe this happened because the tea influenced the connection between the gut and liver, often called the gut-liver axis. While these findings are promising, we still need more human studies to fully unlock the benefits of this tea.

Herbal Teas

Unlike true teas made from the Camellia sinensis plant, herbal teas are made from herbs, fruits, flowers, and roots, and they come with their own special set of health benefits. While they don’t usually affect brainwaves or alertness the way green or black tea might, they offer powerful compounds that target other parts of the body.

Image: vinpearl.com

Here are some key compounds found in herbal teas and what they do:

• Terpenes: Aromatic oils that often have calming, antimicrobial, or digestive effects.

• Flavonoids: Plant pigments with anti-inflammatory effects.

• Phenolic Compounds: A broad category that includes phenolic acids and other compounds with strong antioxidant properties.

The table below outlines some of the most studied compounds found in herbal teas, the teas they are associated with, and how they may benefit the body.

Chemical Compound	Type of Compound	Primary Herbal Tea Source	Effects on the Body
Apigenin	Flavonoid	Chamomile	Calming, promotes sleep, anti-inflammatory, may reduce anxiety
Menthol	Monoterpene	Peppermint	Soothes digestion, relieves headaches, provides cooling sensation
Gingerol	Phenolic Compound	Ginger	Anti-inflammatory, relieves nausea, aids digestion
Cinnamaldehyde	Phenolic Compound	Cinnamon	Anti-inflammatory, antimicrobial, may help regulate blood sugar
Anthocyanins	Flavonoid	Hibiscus, berries	Antioxidant, supports heart health, may lower blood pressure
Linalool	Monoterpene	Lavender, mint	Calming, reduces anxiety, may improve sleep quality

Herbal teas are a great choice if you are sensitive to caffeine or want to try new flavors. They are perfect for relaxation and unwinding.

How Preparation Methods Affect Tea’s Health Benefits

The way you brew your tea can make a big difference. From the water temperature to how long you steep it, these little details help bring out the best flavor and the most benefits. Don’t forget to read the label of your tea as well; it can offer useful brewing instructions and give you a better idea of how to get the most from your tea.

Water Temperature and Steeping Time

• Green tea: Brew at 70–80°C (158–176°F) for 2–3 min. Avoid boiling water, as it can make the tea bitter and reduce its benefits.

• White tea: Brew at 75–85°C (167–185°F) for 3–5 min. If the water is too cool, the tea may taste flat.

• Black tea: More oxidized, black tea tolerates hotter water (90–100°C / 194–212°F) and steeps for 3–5 minutes. The higher temperature and longer steeping time help release beneficial compounds like theaflavins.

• Oolong tea: Brew at 85–95°C (185–203°F) for 3–5 min. Light oolongs prefer cooler water; dark oolongs need hotter water for fuller flavor.

• Dark teas: Brew at 95–100°C (203–212°F) for 3–5 min. Heat and time deepen the earthy flavor.

• Herbal Teas: Flowers and leaves (e.g., chamomile, peppermint) are best steeped at 100°C (212°F) for 5–10 minutes to extract calming properties. Roots and barks (e.g., ginger, cinnamon) require boiling water and 10+ minutes to fully release anti-inflammatory and digestive benefits.

Tea Form

• Loose-leaf tea retains more antioxidants than tea bags, which often contain broken leaves with reduced potency.

• Matcha, a powdered green tea, provides significantly higher levels of EGCG since the whole leaf is consumed. However, its caffeine content is also higher.

• Herbal teas in whole form (e.g., dried flowers, roots) offer more benefits than finely processed bagged versions.

Re-Steeping Potential

• High-quality oolong and dark teas can be steeped multiple times, with each infusion releasing different beneficial compounds.

• Herbal teas are best consumed after the first steep, as some vitamins and nutrients diminish with re-steeping.

Conclusion: Tea’s Lasting Impression

Tea has offered humanity the rare duality of science and spirit. Its rich flavors and soothing aroma are the result of its alchemy: catechins that protect, L-theanine that calms, theaflavins that heal, and so on. This chemistry comes alive through ritual: the careful pouring of water, the gradual unfurling of leaves, and the rising steam all create a moment of mindful presence. In each sip, tea offers both physical and mental nourishment—a balanced blend that lingers with you.

Frequently Asked Questions

1. Can drinking too much tea have adverse side effects?

Like most good things, tea is best enjoyed in moderation. Drinking more than 5 cups daily might make it harder for your body to absorb iron from food, and the caffeine could potentially disrupt sleep if you're sensitive to it or drink it late in the day.

2. Can tea replace or reduce the need for certain medications?

While certain teas can complement healthcare, they shouldn't be considered replacements for prescribed medications. Additionally, some herbal teas may interact with certain medications. It is always smart to check with your doctor before changing your treatment plan.

3. What is the best way to store tea to preserve its flavor and health benefits?

Tea should be stored in an airtight container, away from direct sunlight, moisture, and strong odors. This ensures that the tea maintains its flavor and preserves its beneficial compounds for longer.

4. How long can I store tea before it loses its potency?

Tea is best consumed within 6-12 months of purchase, although the flavor and health benefits may decline after 6 months, especially if stored improperly.

5. Can children safely consume tea?

Most kids are fine with small amounts of caffeine-free herbal teas. For caffeinated teas, it is best to wait until they're older since children tend to be more sensitive to caffeine's effects.

References

1. Cheng, Z., Zhang, Z., Han, Y., Wang, J., Wang, Y., Chen, X., Shao, Y., Cheng, Y., Zhou, W., Lu, X., & Wu, Z. (2020). A review on anti-cancer effect of green tea catechins. Journal of Functional Foods, 74, 104172. https://doi.org/10.1016/j.jff.2020.104172

2. Giesbrecht, T., Rycroft, J. A., Rowson, M. J., & De Bruin, E. A. (2010). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutritional Neuroscience, 13(6), 283–290. https://doi.org/10.1179/147683010X12611460764840 

3. Hu, S., Lin, Z., Zhao, S., Sun, F., & Zeng, L. (2024). Pu-erh tea partly improved liver cholesterol metabolism disorders in colitis mice via the gut-liver axis. Food Science and Human Wellness, 23(4), 1052–1063. https://doi.org/10.26599/FSHW.2024.9250045 

4. Li, J., Romero-Garcia, R., Suckling, J., & Feng, L. (2019). Habitual tea drinking modulates brain efficiency: Evidence from brain connectivity evaluation. Aging, 11(11), 3876–3890. https://doi.org/10.18632/aging.102023:contentReference[oaicite:2]{index=2}

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6. Minich, D. (2023, May 23). How to maximize the health benefits of tea. Dr. Deanna Minich. https://deannaminich.com/how-to-maximize-the-health-benefits-of-tea/ 

7. Seed, S. (2024, March 21). All about herbal tea. WebMD. Medically reviewed by Zilpah Sheikh, MD. Retrieved May 6, 2025, from https://www.webmd.com/food-recipes/ss/slideshow-herbal-tea

8. Tomioka, R., Tanaka, Y., Suzuki, M., & Ebihara, S. (2023). The Effects of Black Tea Consumption on Intestinal Microflora-A Randomized Single-Blind Parallel-Group, Placebo-Controlled Study. Journal of nutritional science and vitaminology, 69(5), 326–339. https://doi.org/10.3177/jnsv.69.326

9. University of Cambridge. (2016, August 24). Just your cup of tea: The history and health claims of the nation's favourite brew. https://www.cam.ac.uk/research/discussion/just-your-cup-of-tea-the-history-and-health-claims-of-the-nations-favourite-brew 

10. Valverde-Salazar, V., Ruiz-Gabarre, D., & García-Escudero, V. (2023). Alzheimer’s disease and green tea: Epigallocatechin-3-gallate as a modulator of inflammation and oxidative stress. Antioxidants, 12(7), 1460. https://doi.org/10.3390/antiox12071460:contentReference[oaicite:2]{index=2}

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12. Zheng, X. X., Xu, Y. L., Li, S. H., Liu, X. X., Hui, R., & Huang, X. H. (2011). Green tea intake lowers fasting serum total and LDL cholesterol in adults: a meta-analysis of 14 randomized controlled trials. The American journal of clinical nutrition, 94(2), 601–610. https://doi.org/10.3945/ajcn.110.010926 

13. Zhao, Y., He, Y., Chen, X., Chen, L., & Liu, Y. (2023). Health-promoting effects of black tea: A narrative review of clinical trials. Frontiers in Nutrition, 10, 11858714. https://doi.org/10.3389/fnut.2023.11858714

    
    

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About Julieta Asenjo, B.S., MSc Candidate

I have always been driven by a deep curiosity for science and a love for sharing knowledge in ways that resonate. As a researcher and writer at BioLife Health Research Center, I focus on conducting research, analyzing data, and developing content for healthcare articles and books. My goal is to share insights that improve health outcomes and spark curiosity about the wonders of life sciences. I am constantly inspired by the chance to learn, grow, and be part of research that drives meaningful change. Follow me on Linkedin.