Herbs and teas have a plethora of properties, and many can help restore balance and support health via their antioxidant content. Depending on the tea and the plant they will act in different ways to the ultimate effect of lowering or normalizing blood pressure (BP). So, if you’re wondering, “can I drink tea if I have high blood pressure”...we have done our research and can tell you exactly what teas do what.
In this blog we will cover:
- An overview of “hypertension”
- Teas for Blood Pressure: True Teas
- Teas for Blood Pressure: Herbal Teas
- Adaptogens and Blood Pressure
The caveat is whether or not you are on blood pressure lowering medications - sometimes teas and herbs which lower blood pressure may interact with the medication. So always talk with your personal healthcare first of course.
An Apple (or Cup of Tea) a Day....
Blood Pressure
Hypertension, another term for “high blood pressure” is estimated to affect 1 billion people and cause 9.4 million deaths per year. It’s a risk factor for cardiovascular diseases, most of which can be mediated by controlling certain lifestyle practices.
Many factors are implicated in hypertension such as genetics, aging, diet and lifestyle including things like: alcohol consumption, smoking, low activity levels, excessive salt intake, and not eating enough fruits and veggies (eat your greens, folks!) (Li, et al., 2019).
Before we give the data we found, let us explain the difference between the top number and bottom number you often see in the blood pressure machine when you visit your doctor, as this will be important in the next section:
- Systolic blood pressure: the top number on the blood presure read out, represents the force of the heart beat on the walls of the arteries.
- Diastolic blood pressure: the bottom number, is the force on the walls of the arteries in between beats.
Okay now we have a quick overview, let’s turn to why you’re reading: Is tea good for lowering blood pressure?
Teas for Blood Pressure / Hypertension
On this subject, we found a great 13-study review which conducted a “meta-analysis”, that is, the overall analysis of all the results across all the studies.
This broad tea + blood pressure (BP) study of studies shows green and black teas reduce the risk of cardiovascular diseases, believed to be caused by the high polyphenol content in tea (particularly flavonoids) - these technical terms are types of antioxidants.
Antioxidants are essential natural compounds, which when in abundance is usually the reason nutritionists refer to something being a “superfood” - like blueberries…or tea! Taking a closer look, other studies scrutinized the benefits of flavonoid content in tea and found they were responsible for controlling and treating hypertensive conditions (Li, et al., 2019).
➔ Read our whole series on the benefits of antioxidants in tea, starting with Part 1: What Are Antioxidants and How Do They Work?
Green Tea & Hypertension
This appears to benefit people who already have an elevated BP. This review found that green tea lowered Systolic BP by 2.08 mmHg and Diastolic BP by 1.71 mmHg (mmHg is a measure of blood pressure), and greater reduction was seen in those with an average systolic blood pressure of ≥130 mmHg. This is good news since data shows just a 5 mmHG drop in blood pressure will lower risk of ischemic heart disease by 21% and stroke by 34%! (Li, et al., 2019)
➔ Click for our climate-friendly ethical green teas We have Japanese green teas, such as sencha, genmaicha and hojicha, Chinese green teas such as dragonwell and jasmine, plus fruity, floral & chai blends...
Black Tea & Hypertension
A study including about 20,000 men and women found that cholesterol was significantly lowered and that as tea consumption increased, BP decreased (2.1 mmHg for men and 3.5 mmHG for women). Meanwhile, a study of 95 men and women found that regularly consuming 3 cups per day of black tea (approx. 429 mg of polyphenols per day) lowered Systolic BP and Diastolic BP between 2-3 mmHG (Li, et al., 2019).
➔ Click for our rich carbon-offsetting black teas
Which true tea is better for lowering blood pressure / hypertension?
Looking at black and green tea comparatively…while both lowered BP (and had a greater effect the longer the teas were consumed: ie., >12 weeks) green tea had a greater effect. However, it was concluded that both teas could significantly decrease BP.
The teas were effective in obese populations and in the general population, too! They found that those who regularly consumed 10g of tea daily had lower BP scores than non-tea drinkers. Another conclusion found that those who drank green or oolong tea at moderate strength- at least half a cup per day- had a 46% lower risk of developing high blood pressure. (Li, et al., 2019)
So don’t wait, start your tea habit early!!
Herbal Teas for Blood Pressure / Hypertension
Hibiscus Tea & Blood Pressure
One type of antihypertensive medication are Angiotensin-converting enzyme inhibitors (ACE-inhibitors) --- jargon alert!! --- basically this prevents the narrowing of blood vessels. According to the various studies we read, it is believed that hibiscus lowers blood pressure by two mechanisms- diuretic (ridding the body of salt) and through ACE inhibition - just like the medication we just mentioned. Pretty cool!
Two other trials found a third mechanism of action: something called a natriuretic effect. This time, the techy term natriuresis means lowering blood volume and sodium concentration (lowering BP via osmosis). For four weeks two groups with stages I or II hypertension were given either lisinopril (a medication used in the control group) or a dried hibiscus extract containing 250 mg of anthocyanins per dose (a type of antioxidant). The hibiscus group saw an effectiveness outcome of 65.12% and a 100% safety and tolerability outcome of the participants (Herrera-Arellano, et al., 2007).
Another similar study used a liquid extract of hibiscus with far fewer anthocyanins (only 9.6 mg) and compared it to a group using 50 mg of the medication captopril. This lovely plant was just as effective as the medication in this study (Herrera-Arellano, et al., 2004).
Finally, a final but very small study we found compared hibiscus tea consumption to a common anti-hypertensive medication, with placebo control. Both the tea and medication lowered BP but the tea was more effective in mild to moderate hypertension and comparatively did not cause electrolyte imbalance like the comparison drug (Nwachukwu, et al., 2015).
➔ Try our Tart & Tangy Pure Hibiscus Petals from Egypt - fantastic to blend with other teas
Rooibos Tea & Blood Pressure
Rooibos caused ACE-inhibiting activity after just 30 minutes of consuming it (ACE is a type of drug action which prevents the narrowing of blood vessels). Its effects were greater at 60 minutes. This is an acute example and the study didn’t look at long term effects, but it did determine that Rooibos has these effects via ACE inhibition fairly rapidly (Persson, et al., 2010).
While few studies have looked at Rooibos and blood pressure directly (we are always honest in our research!), cholesterol can impact and raise BP via the narrowing and hardening of arteries and Rooibos may be an unsung hero in this case. A study found that those drinking 6 cups of rooibos tea over 6 weeks saw a significant decrease in LDL “bad” cholesterol and an increase in HDL “good” cholesterol compared to the control group. Even redox status improved (which is a balance between antioxidants and pro-oxidants). This is important because redox status is implicated in cardiovascular disease (Marnewicke, et al 2011).
➔ Like all our teas, our Rooibos & Honeybush is from the Ethical Tea Partnership: Red rooibos is oxidized, whereas green rooibos is unoxidized, so higher in antioxidants with a lighter flavor. Honeybush is a botanical cousin of rooibos, similarly grown in South Africa, with a beautiful honey-like citrus sweet-sourness.
Ginger Tea & Blood Pressure
In a large literature review it was found that ginger supplementation of 3g or more per day for a duration of up to 8 weeks in adults up to age fifty significantly lowered Systolic BP and Diastolic BP. We would note that in this review, the follow up consultations were conducted at 8 weeks but not carried out longer. This isn't saying that it lost effectiveness, but that this length of time was needed (in the studies) to get the results
Other parameters saw benefits to BP levels but need more research to be more definitive (Hasani, et al., 2019). According to another study, ginger’s ability to lower blood pressure is due to “calcium-channel blocking” - which without needing to know what this means, you should know this is a mechanism which is used by existing blood pressure medications (Ghayur & Gilani, 2005).
➔ Our Pep You Up Pure Thai Ginger is strong and spicy, refreshing and zingy, and containing a powerful anti-inflammatory
What about Adaptogens to Lower Blood Pressure?
Interestingly, most adaptogens (a class of herb) do not have specific cardiovascular effects (compared to their numerous other effects). However they do have beneficial actions which can include normalizing blood pressure (Winston & Maimes, 2007)!
Let's investigate two famous adaptogens below:
➔ “Adaptogens” are a class of herbs that help us “adapt” to stress, regardless of the origin of the stressor. You can read more in our blog: What are Adaptogens and Why Are They Good For You? Part 1
Moringa Tea & Blood Pressure
This miracle-herb shines again! In one study, Moringa leaf significantly reduced Systolic BP and Diastolic BP in participants taking juiced Moringa leaves (just 15 of them in this case) 2x daily. Participants were male and had stage I hypertension (Kumar, et al., 2019).
Another study, a pilot, suggests that the compounds isothiocyanate and niaziminin found in moringa are responsible for the anti-hypertensive effects (Subrahmonyan, et al., 2020)! Additionally, a rat study found that the liquid extract of moringa leaves alleviated hypertension by causing vasodilation (relaxing and expanding blood vessels) due to the antioxidant effects on oxidative stress and vascular dysfunction (Aekthammarat, et al., 2019).
Tulsi Tea & Blood Pressure
Holy Basil demonstrates the normalizing effects of adaptogens in studies looking at blood pressure levels attenuated by this herb, that is, to reduce extremes both high and low. In two short studies of 10 - 12 days participants with high blood pressure consumed 30 mLs of juiced tulsi 1 - 2x daily, respectively, and saw significant decreases in BP levels. Meanwhile, a study with hypotensive rats (that’s hypo not hyper, which is low blood pressure) found that tulsi normalized their BP levels (Jamshidi & Cohen, 2017).
A rat study found that Tulsi also lowers cholesterol due to the Eugenol content. It does so by decreasing serum lipid levels, lipid peroxidation, and improving cardiac antioxidant enzymes (Suanarunsawat, et al., 2010). A cell study concluded that Tulsi inhibits an oxidative enzyme involved in the development of atherosclerosis (hardening of arteries); both conditions which may exacerbate hypertension by driving up BP levels (Narasimhulu & Vardham, 2015).
So a whole host of positive effects, but which need further larger scale investigation and on humans not just rats. (Notice how many blogs never cast doubt on anything they say, but we are a science led blog, and that means sharing when the evidence is not yet strong / conclusive).
Try our Moringa & Tulsi adaptogenic teas + our pure forms are also organic.
A Note From The Herbalist...
It is important to know that you should never self medicate if you have a disease without appropriate professional advice. Adding tea in therapeutic doses to existing blood pressure medications may create side effects such as to make the medication less effective by blocking it or metabolizing it more quickly. Or it may have additive effect s- meaning it might make your blood pressure drop too low. So, always consult with your doctor. Many doctors will work with your lifestyle and adjust dosage accordingly.
In fact, Medical News Today warns about this very thing when combining Moringa and anti-hypertensive medication (Wilson, 2020). Which reminds me… I have an anecdote for you. When I was young, naive, and long before my formal education, I started taking olive leaf extract for a coxsackievirus I’d picked up from working with toddlers. In my brief research I misread some mathematical instructions and miscalculated my dose. I found out the hard way that olive leaf extract lowers blood pressure when taken in large doses and actually passed out! Be cautious about about how much you are taking, and about combining herbs and medications. But don’t be scared, they truly can work wonderfully together, it’s just about consult a qualified healthcare practitioner when making changes or adding herbs to medications!
Questions? Thoughts? Let me know in the comments below or on our IG @MatchaAlternatives
About the Author
Stephany went on to earn her MSc in Complementary Alternative Medicine at the American College for Healthcare Sciences (ACHS), where she focused her studies on Herbal Medicine and Nutrition. Most recently, she completed her Graduate Certification in Nutrition from ACHS in 2020. She is currently a professor at White Earth Tribal and Community College (WETCC) in Minnesota as part of a pilot project with Lead for America.
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Tea & Blood Pressure References & Further Reading
Li, D., Wang, R., Huang, J., Cai, Q., Yang, C. S., Wan, X., & Xie, Z. (2019). Effects and Mechanisms of Tea Regulating Blood Pressure: Evidences and Promises. Nutrients, 11(5), 1115. https://doi.org/10.3390/nu11051115
Nwachukwu, D. C., Aneke, E., Nwachukwu, N. Z., Obika, L. F., Nwagha, U. I., & Eze, A. A. (2015). Effect of Hibiscus sabdariffaon blood pressure and electrolyte profile of mild to moderate hypertensive Nigerians: A comparative study with hydrochlorothiazide. Nigerian journal of clinical practice, 18(6), 762–770. https://doi.org/10.4103/1119-3077.163278
Nwachukwu, D. C., Aneke, E., Nwachukwu, N. Z., Obika, L. F., Nwagha, U. I., & Eze, A. A. (2015). Effect of Hibiscus sabdariffaon blood pressure and electrolyte profile of mild to moderate hypertensive Nigerians: A comparative study with hydrochlorothiazide. Nigerian journal of clinical practice, 18(6), 762–770. https://doi.org/10.4103/1119-3077.163278
Herrera-Arellano, A., Miranda-Sánchez, J., Avila-Castro, P., Herrera-Alvarez, S., Jiménez-Ferrer, J. E., Zamilpa, A., Román-Ramos, R., Ponce-Monter, H., & Tortoriello, J. (2007). Clinical effects produced by a standardized herbal medicinal product of Hibiscus sabdariffa on patients with hypertension. A randomized, double-blind, lisinopril-controlled clinical trial. Planta medica, 73(1), 6–12. https://doi.org/10.1055/s-2006-957065
Herrera-Arellano, A., Flores-Romero, S., Chávez-Soto, M. A., & Tortoriello, J. (2004). Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: a controlled and randomized clinical trial. Phytomedicine : international journal of phytotherapy and phytopharmacology, 11(5), 375–382. https://doi.org/10.1016/j.phymed.2004.04.001
Hasani, H., Arab, A., Hadi, A., Pourmasoumi, M., Ghavami, A., & Miraghajani, M. (2019). Does ginger supplementation lower blood pressure? A systematic review and meta-analysis of clinical trials. Phytotherapy research : PTR, 33(6), 1639–1647. https://doi.org/10.1002/ptr.6362
Ghayur, M. N., & Gilani, A. H. (2005). Ginger lowers blood pressure through blockade of voltage-dependent calcium channels. Journal of cardiovascular pharmacology, 45(1), 74–80. https://doi.org/10.1097/00005344-200501000-00013
Persson, I. A., Persson, K., Hägg, S., & Andersson, R. G. (2010). Effects of green tea, black tea and Rooibos tea on angiotensin-converting enzyme and nitric oxide in healthy volunteers. Public health nutrition, 13(5), 730–737. https://doi.org/10.1017/S1368980010000170
Marnewick, J. L., Rautenbach, F., Venter, I., Neethling, H., Blackhurst, D. M., Wolmarans, P., & Macharia, M. (2011). Effects of rooibos (Aspalathus linearis) on oxidative stress and biochemical parameters in adults at risk for cardiovascular disease. Journal of ethnopharmacology, 133(1), 46–52. https://doi.org/10.1016/j.jep.2010.08.061
Wilson, D. (2020). Moringa: Benefits, side effects, and risks. https://www.medicalnewstoday.com/articles/319916#risks-with-existing-medications
Kumar, S. S., Jabir, P. K., Madhusudhan, U., Archana, R., Mukkadan, J. K. (2020). Effect of Moringa oliefera leaves on blood pressure in hypertensive patients. In Indian Journal of Clinical Anatomy and Physiology (Vol. 5, Issue 3, pp. 350–352). IP Innovative Publication Pvt Ltd. https://doi.org/10.18231/2394-2126.2018.0081
Subrahmonyan, Balaji & Senan, Lakshmy & Tripathy, Rabinarayan. (2021). Anti-hypertensive effect of Moringa oleifera lam. Leaves decoction -A pilot study Original Research Paper. Retrieved from https://www.researchgate.net/publication/355903633_ANTI-HYPERTENSIVE_EFFECT_OF_Moringa_oleifera_lam_LEAVES_DECOCTION_-A_PILOT_STUDY_Original_Research_Paper
Aekthammarat, D., Pannangpetch, P., & Tangsucharit, P. (2019). Moringa oleifera leaf extract lowers high blood pressure by alleviating vascular dysfunction and decreasing oxidative stress in L-NAME hypertensive rats. Phytomedicine : international journal of phytotherapy and phytopharmacology, 54, 9–16. https://doi.org/10.1016/j.phymed.2018.10.023
Jamshidi, N., & Cohen, M. M. (2017). The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature. Evidence-based complementary and alternative medicine : eCAM, 2017, 9217567. https://doi.org/10.1155/2017/9217567
Narasimhulu, C. A., & Vardhan, S. (2015). Therapeutic Potential of Ocimum tenuiflorum as MPO Inhibitor with Implications for Atherosclerosis Prevention. Journal of medicinal food, 18(5), 507–515. https://doi.org/10.1089/jmf.2014.0125
Suanarunsawat, T., Devakul Na Ayutthaya, W., Songsak, T., Thirawarapan, S., & Poungshompoo, S. (2010). Antioxidant Activity and Lipid-Lowering Effect of Essential Oils Extracted from Ocimum sanctum L. Leaves in Rats Fed with a High Cholesterol Diet. Journal of clinical biochemistry and nutrition, 46(1), 52–59. https://doi.org/10.3164/jcbn.09-52
Winston, D., & Maimes, S. (2007). Adaptogens - herbs for strength, stamina and stress relief. Healing Arts Press.