Hibiscus tea, also known as sour tea, has been recently investigated for its heart protective effects. I’ve enjoyed hibiscus tea personally but more recently discovered its effects on cholesterol and lowering blood pressure.
An extract of the herb Hibiscus sabdariffa has been shown in animal studies to lower LDL cholesterol and increase HDL cholesterol. It works by decreasing fatty acid synthase (the enzyme that makes fatty acids) and lowers HMG CO-A reductase (just like statin drugs). It also increases LDL receptor expression (which lowers blood LDL levels).
Interestingly this same plant also acts on inhibiting Angiotensin I Converting Enzyme (ACE), which is the same action in a well-known class of blood pressure lowering drugs. Several human clinical trials showed significant reductions in blood pressure mostly taking hibiscus in a tea form. Systolic blood pressure dropped on average between 5-11%. One study showed similar effectiveness of hibiscus and captopril (an ACE inhibiting class of blood pressure lowering medication).
Another study in 2010 showed a small but significant reduction of serum triglycerides by 10% compared to a control group when supplementing with HSE capsules at a dose of 500mg twice a day. HSE stands for Hibiscus sabdariffa 74% Polyphenol Extract.
One study also showed a reduction in fasting glucose by 6.7% in normal patients and reduced blood glucose 8.4% in those patients with metabolic syndrome. HSE was given in capsule form.
Hibiscus tea benefits a wide range of benefits of reducing blood pressure and abnormal lipid metabolism, especially triglycerides. These heart healthy effects make this sour tea kind of sweet.
References:
1. Yang MY, Peng CH, et al. The hypolipidemic effect of Hibiscus sabdariffa polyphenols via inhibiting lipogenesis and promoting hepatic lipid clearance. J Agric Food Chem 2010 Jan 27;58(2):850-9
2. Ojeda D, Jimenez-Ferrer E, et al. Inhibition of angiotensin converting enzyme (ACE) activity by the anthocyanins delphinidin- and cyaniding-3-O-sambubiosides from Hibicus sabdariffa. J Ethnopharmacol 2010 Jan 8:127(1)7-10
3. McKay DL, et al. Hibiscus sabdariffa L. tea lowers blood pressure in prehypertensive and mildly hypertensive adults. J Nutr 2010 Feb; 140(2):298-303
4. Herrera-Arellano A. et al. Effectiveness and tolerability of a standardized extract from Hibiscus sabdariffa in patients with mild to moderate hypertension: a controlled and randomized clinical trial. Phytomedicine 2004 Jul;11(5):375-82
5. Herrera-Arellano A, et al. 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 Med 2007 Jan; 73(1):6-12
6. Faraji MH, Tarkhani AHH. The effect of sour tea (Hibiscus sabdariffa) on essential hypertension. J Ethnopharmacol. 1999 Jun;65(3):231-6
7. Gurrola-Diaz CM, Garcia-Lopez PM, et al. Effects of Hibiscus sabdariffa extract powder and prevention treatment (diet) on the lipid profiles of patients with metabolic syndrome. Phytomedicine 2010 Jun;17(7):500-5