There is a growing interest in the use of herbs or plant based treatments for hypertension. The term herb itself refers to the leafy part of plants while spices are used in contrast referring to all the other parts i.e. fruits, bark, stem, roots etc. The WHO itself has shown an interest in what it calls Traditional Medicine (TM) Strategy (1) which aims to support Member States in developing proactive policies and implementing action plans that will strengthen the role traditional medicine plays in keeping populations healthy.
Research studies have started to explore the use of different plant based medicines both as an independent therapy and as an adjunct to standard medical therapies. There have been a number of Randomized Controlled Studies (RCTs) looking at the subject with most of the research being coming from China and India which have well established systems of traditional medicine which is now being married with modern scientific techniques and classifications to categorize the usefulness of such treatments. There are sporadic reports of plant based treatments from other parts of the world such as Iran, Korea, Lebanon and other countries.
The issue of standardization of treatments is problematical. Studies have tried to use modern methods such as High Performance Liquid Chromatography to examine the exact constituents of plant based therapies. What they have found is that the same preparation of traditional medicines can vary significantly in their constituent amounts. Plants tend to be grown at a particular time of year differ in the chemical constituents of their leaves, the place where they are grown also makes a difference and so on. This itself is a potential stumbling block in the analysis of such treatments and their efficacy in the treatment of hypertension.
Most studies that have looked at this tend to be small and there are very few head-to-head studies which compare the effects of a particular regime of traditional medicines versus newer pharmaceutical agents. Where these have been done the quantity of traditional medication has been at least three times daily. Most traditional plant based therapies can be prepared through a simple means in a persons kitchen such as boiling whole plant material. This process is known as “infusion”. If the plant material is crushed and then boiled this is known as a “decoction”.
Commercial preparations that can be found in health food stores are formed by a more intricate process with chemical processes to extract plant based components such as extracts formed by alcohol or water based extraction of components which are then purified or dried and then mixed in certain amounts as per ancient formulas. Sometimes these can include other non-plant based components such as coral powder and elements such as Magnesium.
The safety of such traditional based treatments varies, some are very safe such as one TM such as Saffron powder, a spice made from a ground flower, and another using Horse Mint leaves (a herb from the plant commonly used in Arabia in tea). One study on Saffron powder showed that the consumption of 100mg / day reduced blood pressure by about 7/2 mm Hg for the systolic and diastolic readings.(2) Another study on Horse Mint infusions, given once daily, showed a reduction in blood pressure of 12/6 mm Hg.(3) Both saffron powder and Horse Mint are traditionally used herbs and spices in the Middle East and South Asia and their safety has not been called into question over the many hundreds of years they have been used in cooking.
On the other hand some Chinese TMs have been implicated in liver damage and deaths. One such example is a Chinese TM called Tianma Gouteng Yin (TGY). Among the many herbs and ingredients it contains is the dried stem of the Tuber fleeceflower (Polygonum multiflorum Thunb.). This particular ingredient has been associated with 441 case reports of liver damage and also seven deaths and two cases requiring a liver transplant. (4)
Judging from the large interest in the topic, though chiefly fueled by China, there seems to be a significant role for the regular consumption of traditional medicines or plant based therapies in the treatment of hypertension especially as an adjunct to pharmaceutical based medicines in order to reduce the total dose consumed and achieve better control of hypertension through a means that is more palatable to patients.
InshaAllah in the next article I would like to look at one more new treatment for hypertension which is based on biofeedback devices.
- Qi, Zhang. “WHO Traditional Medicine Strategy. 2014-2023.” Geneva: World Health Organization (2013).
- Ebrahimi, Fatemeh, et al. “The effect of saffron (Crocus sativus L.) supplementation on blood pressure, and renal and liver function in patients with type 2 diabetes mellitus: A double-blinded, randomized clinical trial.” Avicenna journal of phytomedicine 9.4 (2019): 322.
- Samaha, Ali A., et al. “Antihypertensive Indigenous Lebanese Plants: Ethnopharmacology and a Clinical Trial.” Biomolecules 9.7 (2019): 292.
- Lei, Xiang, et al. “Liver damage associated with Polygonum multiflorum Thunb.: a systematic review of case reports and case series.” Evidence-Based Complementary and Alternative Medicine 2015 (2015).