The Healing Power of Tea

From cardiovascular health and antioxidant protection to digestion, immune support, and better sleep, here’s how to choose teas based on their medicinal properties.

As temperatures drop and we spend more time indoors, a warm cup of tea can become more than just a comforting ritual. Many teas contain naturally occurring plant compounds with antioxidant, anti-inflammatory, antimicrobial, and potentially cardioprotective properties.

Depending on the plant, tea may offer benefits ranging from modest improvements in blood pressure and cholesterol to digestive support, relaxation, and even hormonal effects. While some of these benefits are supported by human research, others are still being explored.

Let’s look at which teas are worth knowing about, what the research actually shows, and how to choose the best quality options.

What Makes Tea Beneficial?

When we talk about the medicinal properties of tea, we’re largely referring to its naturally occurring plant compounds, particularly polyphenols.

These compounds have been studied for their ability to influence oxidative stress, inflammation, vascular function, and metabolic health. Some of the most notable include:

• Catechins: Polyphenols found in green tea, including EGCG, which has been extensively studied for antioxidant and cardiometabolic effects.
• Anthocyanins: Pigments found in plants such as hibiscus that contribute to their deep color such as red, purple, and blue.
• Flavonoids: A broad family of plant compounds found in chamomile, black tea, and many other botanicals.
• Terpenes and essential oils: Aromatic compounds found in herbs such as peppermint and ginger that contribute to their characteristic flavors and potential digestive properties.

The presence of these compounds doesn’t automatically guarantee clinical benefit. The amount consumed, how the tea is prepared, the concentration of active compounds, and how the body absorbs and metabolizes them all matter.

Which Tea Is Best for What? A Quick-Reference Guide

Tea	Potential Health Benefits	Amount Used in Research	Research Findings
Black tea	Blood pressure	3 cups daily for 6 months using a standardized powdered-tea preparation	About 2 mmHg lower systolic and diastolic blood pressure versus placebo in one randomized controlled trial. [7]
Chamomile	Sleep-related symptoms	1 cup daily for 2 weeks; 2 g dried flowers in 300 mL hot water	A trial of 80 postpartum women found improvement in certain sleep-related symptoms and depressive symptom scores. [4]
Ginger	Nausea (especially pregnancy-related)	No established therapeutic tea dose	Human research supports ginger for certain types of nausea, although much of the evidence involves supplements. [11]
Green tea	Cardiovascular and metabolic health	4 cups/day for 8 weeks in one brewed-tea trial; no established LDL-lowering cup count	A meta-analysis of 31 trials found an average LDL reduction of approximately 4.6 mg/dL. [15]
Hibiscus	Blood pressure	3 cups daily for 6 weeks; 1.25 g dried hibiscus calyx per cup in the cited trial	Approximately 6 mmHg greater reduction in systolic blood pressure than placebo in one randomized, placebo-controlled trial. [9]
Lavender	Anxiety and mood symptoms	One 2 gram tea bag twice daily for 2 weeks	A short trial in older adults found improvements in anxiety and depressive symptom scores versus control. [3]
Passionflower	Sleep-related symptoms	1 cup nightly for 7 days	Improved subjective sleep quality in a small clinical trial. [13]
Peppermint	Digestive discomfort and IBS	No established therapeutic tea dose	Stronger evidence exists for enteric-coated peppermint oil than for peppermint tea. [12]
Rooibos	Lipid and oxidative-stress markers	6 cups daily for 6 weeks in one study	A study of 40 adults at cardiovascular risk reported favorable biomarker changes, showing preliminary evidence. [10]
Spearmint	Androgen levels in women with PCOS	2 cups daily for 30 days	Reduced free and total testosterone in a small trial, but objective hair-growth changes were not significant. [5]
Turmeric	Anti-inflammatory and antioxidant activity	No established therapeutic tea dose	Curcumin is extensively studied, but concentrated extract findings cannot be directly applied to turmeric tea.
White tea	Metabolic and cholesterol effects	2 cups daily for 12 weeks	One study showed some cholesterol and metabolic measurement improvements from baseline but did not demonstrate a significant between-group benefit for blood lipids. [2]

How to Choose High-Quality Tea

Herbs and teas are agricultural products. Their quality can be influenced by where they’re grown, how they’re harvested and dried, how they’re stored, and how they’re processed. This is why I pay just as much attention to the quality of tea as I do the type. 

Here are a few things I look for:

• Organic certification: Choosing certified organic products can reduce exposure to certain pesticide residues, although organic certification does not guarantee that a product is free from contaminants.
• Transparent sourcing: Look for companies that identify the botanical species, plant part, and country of origin.
• Third-party testing and certificates of analysis (COAs): Ideally, testing should address botanical identity, heavy metals (including lead, arsenic, cadmium, and mercury), pesticide residues, microbial contamination, and adulteration.
• Freshness and storage: Herbs should have their characteristic color and aroma and be stored in sealed packaging away from heat, moisture, and light.

One company I recommend often is Mountain Rose Herbs. I’ve been a fan of their approach to sourcing and quality for a long time. They offer an extensive selection of organic herbs and botanicals and publish information about their quality-control practices, including botanical identity testing, microbial testing, and risk-based screening for chemical contaminants and heavy metals. Certificates of analysis are available for tested products. You can explore their sourcing practices and quality-control and testing program.

Loose-Leaf Tea vs. Tea Bags: What About Microplastics?

I’m a big proponent of loose-leaf tea, and one reason is that it gives you more control over what you’re actually steeping in your cup.

Many conventional tea bags contain polypropylene, nylon, or other plastic materials, either in the bag itself or in the heat-sealed areas. These materials can release microplastics and nanoplasticswhen exposed to hot water.

A 2019 study published in Environmental Science & Technology found that steeping certain plastic tea bags at 95°C released billions of microplastic and nanoplastic particles into a single cup. [6]

More recent research published in npj Science of Food in October 2026 again found substantially greater particle release from the tested plastic tea bags than from bulk tea. In this study, researchers tested 14 bagged and 14 bulk tea brands and found that the plastic tea bags released substantially more microplastic particles. The researchers also assessed chemical migration, including bisphenol A and phthalate esters. [14]

We still don’t have enough human research to fully understand the long-term health effects of these exposures. So, when there are simple, practical ways to reduce unnecessary exposure, I recommend taking advantage of them. 

How to Choose Decaffeinated Tea

If you enjoy a variety of tea beyond herbal options but want less caffeine, look for brands that disclose their decaffeination methods. Conventional methods use chemical solvents, such as methylene chloride or ethyl acetate, to extract caffeine. Although these solvents are removed and residue limits are regulated, some people prefer to avoid solvent-based processing.

Water-based decaffeination, such as the Swiss Water Process, and CO₂ processing are alternatives to conventional solvent-based methods. One example is Yu Tea Organic Decaf Sencha, which uses water-only processing and contains approximately 4 mg of caffeine per 8-ounce serving, compared with roughly 20–40 mg in a typical serving of brewed green tea. 

What to Consider Before Making Tea a Daily Habit

Although tea is generally safe for most healthy adults, medicinal herbs deserve the same thoughtfulness we would give to supplements.

• Caffeine and sleep: Green, black, white, and oolong teas naturally contain caffeine. The amount varies with the variety, serving size, and steeping time. If you’re sensitive to caffeine or struggle with sleep, consider limiting these teas to the morning or early afternoon.
• Iron absorption: This is particularly important for menstruating women, pregnant women, and anyone with low ferritin or iron deficiency. Tea polyphenols can bind to non-heme iron, the form found in plant foods and many fortified foods, reducing its absorption when consumed alongside a meal. One controlled human study found that waiting one hour after an iron-containing meal reduced the inhibitory effect. [1] If iron status is a concern, I generally recommend separating tea from iron-rich meals and iron supplements.
• Pregnancy and breastfeeding: Not all medicinal herbs are appropriate during pregnancy or breastfeeding. Caffeine intake also deserves attention during pregnancy. Anyone pregnant, trying to conceive, or breastfeeding should check with their healthcare provider about which herbs/teas are safe for them.
• Medication interactions: Certain herbs can influence blood pressure, blood sugar, electrolyte balance, and medication activity. Hibiscus, senna, and licorice root are examples worth discussing with a healthcare provider before regular medicinal use. Licorice, in particular, cancontribute to elevated blood pressure and potassium depletion.
• Concentrated extracts are not the same as tea: A cup of green tea is not equivalent to a concentrated EGCG supplement. A cup of peppermint tea is not equivalent to an enteric-coated peppermint oil capsule. And turmeric tea is not equivalent to a standardized curcumin extract. The preparation, concentration, absorption, and effects can be very different.

The Takeaway: A Healthy Daily Ritual

Tea isn’t a substitute for a nutrient-dense diet, quality sleep, movement, or medical care, but it can be a wonderful way to add more beneficial plant compounds to your routine.

Tea can also contribute to your weekly plant diversity. Research from the American Gut Project found that people eating 30 different plant foods per week tended to have more diverse gut microbiomes. [8]

After all, some of the best health habits are the ones we look forward to every day. A warm cup of tea is a wonderful place to start.

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References

1. Ahmad Fuzi SF, Koller D, Bruggraber S, Pereira DI, Dainty JR, Mushtaq S. A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope. Am J Clin Nutr. 2017;106(6):1413-1421. doi:10.3945/ajcn.117.161364
2. Akyildiz K, Yilmaz A, Avci U, Toraman MN, Yazici ZA. White tea consumption alleviates anthropometric and metabolic parameters in obese patients. Medicina (Kaunas).2024;60(10):1568. doi:10.3390/medicina60101568
3. Bazrafshan MR, Jokar M, Shokrpour N, Delam H. The effect of lavender herbal tea on the anxiety and depression of the elderly: a randomized clinical trial. Complement Ther Med. 2020;50:102393. doi:10.1016/j.ctim.2020.102393
4. Chang SM, Chen CH. Effects of an intervention with drinking chamomile tea on sleep quality and depression in sleep disturbed postnatal women: a randomized controlled trial. J Adv Nurs. 2016;72(2):306-315. doi:10.1111/jan.12836
5. Grant P. Spearmint herbal tea has significant anti-androgen effects in polycystic ovarian syndrome: a randomized controlled trial. Phytother Res. 2010;24(2):186-188. doi:10.1002/ptr.2900
6. Hernandez LM, Xu EG, Larsson HCE, Tahara R, Maisuria VB, Tufenkji N. Plastic teabags release billions of microparticles and nanoparticles into tea. Environ Sci Technol.2019;53(21):12300-12310. doi:10.1021/acs.est.9b02540
7. Hodgson JM, Puddey IB, Woodman RJ, et al. Effects of black tea on blood pressure: a randomized controlled trial. Arch Intern Med. 2012;172(2):186-188. doi:10.1001/archinte.172.2.186
8. McDonald D, Hyde E, Debelius JW, et al. American Gut: an open platform for citizen science microbiome research. mSystems. 2018;3(3):e00031-18. doi:10.1128/mSystems.00031-18 
9. McKay DL, Chen CY, Saltzman E, Blumberg JB. Hibiscus sabdariffa L. tea (tisane) lowers blood pressure in prehypertensive and mildly hypertensive adults. J Nutr.2010;140(2):298-303. doi:10.3945/jn.109.115097
10. Marnewick JL, Rautenbach F, Venter I, et al. Effects of rooibos (Aspalathus linearis) on oxidative stress and biochemical parameters in adults at risk for cardiovascular disease. J Ethnopharmacol. 2011;133(1):46-52. doi:10.1016/j.jep.2010.08.061
11. National Center for Complementary and Integrative Health. Ginger: usefulness and safety. Accessed November 9, 2026. https://www.nccih.nih.gov/health/ginger
12. National Center for Complementary and Integrative Health. Peppermint oil: usefulness and safety. Accessed November 9, 2026. https://www.nccih.nih.gov/health/peppermint-oil
13. Ngan A, Conduit R. A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality. Phytother Res.2011;25(8):1153-1159. doi:10.1002/ptr.3400
14. Pehlivan N, Gedik K. Microplastic release from plastic tea bags versus bulk tea and migration of bisphenol A and plasticizer esters. npj Sci Food. 2026. doi:10.1038/s41538-026-01175-x
15. Xu R, Yang K, Li S, Dai M, Chen G. Effect of green tea consumption on blood lipids: a systematic review and meta-analysis of randomized controlled trials. Nutr J. 2020;19:48. doi:10.1186/s12937-020-00557-5