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Two recent studies have shown that stevia in doses somewhat higher than those used for sweetening work well as a treatment for high blood pressure (1/4 teaspoon three times a day or enough to sweeten 12-24 cups of tea or coffee at a cost of $3 per month). In a two year human study, it considerably reduced the risk of developing left ventricular hypertrophy of the heart. Stevia also appears to be of benefit in lowering blood sugar in diabetics by increasing the effectiveness of insulin. Stevioside causes very little toxicity with no reports of allergic reactions or side-effects of any type in humans. Phytochemistry. 2003 Nov;64(5):913-21. Even at extremely high doses, it has had not carcinogenic or other harmful effects in multiple animal studies. Metabolism. 2003 Mar;52(3):372-8. It had no teratogenic effects on developing chicken embryos (J Agric Food Chem. 2003 Aug 13;51(17):5162-7). It had no adverse effects with chronic consumption of very high levels in chicken (J Agric Food Chem. 2003 Feb 12;51(4):1095-101). Stevia at very high doses did decrease testicular function and fertility in rats (J Ethnopharmacol. 1999 Nov 1;67(2):157-61). Also, at very high doses, equivalent to 160 times that used in the above hypertension study, there were harmful effects on hamster fetuses, but not at 80 times. (Drug Chem Toxicol. 1998 May;21(2):207-22). While more human research is definitely needed to verify any benefit for diabetes and to measure whether or not it lowers mortality rates, enough is available to recommend is use as a sweetener. I haven't seen any reports on how it holds up in cooking, but in my one batch of peanut butter cookies, there didn't seem to be any loss in sweetness. However, Nutrition Action considers stevia to be inadequately studied for safety. Stevioside Sweetener Helps Hypertension: A two year 174-patient DB PC study of Taiwanese with mild high blood pressure found stevioside 500 mg (1/2 teaspoon) 3 times a day lowered systolic BP from 150 to 140 and diastolic from 95 to 89. Side-effects were the same in both groups. Quality of Life was better with stevioside. The percentages developing left ventricular hypertrophy of the heart were 6% for stevioside and 24% for placebo. Taiwan Univ. Efficacy and tolerability of oral stevioside in patients with mild essential hypertension: A two-year, randomized, placebo-controlled study. Hsieh MH, Chan P, Sue YM, Liu JC, Liang TH, Huang TY, Tomlinson B, Chow MS, Kao PF, Chen YJ. Clin Ther. 2003 Nov;25(11):2797-808; Steviol's hypotensive mechanism may be due to inhibition of the Ca(2+) influx. Pharmacology. 2003 Jan;67(1):14-20. While calcium channel blockers, like nifedipine (Procardia), also inhibit calcium influx, there must be important differences, because steviosides has virtually no side-effects while calcium channel blocker cause frequent dizziness, flushing, peripheral edema, muscle cramps and other side-effects. A more recent study suggests that a selective relaxation of the potassium channel by isosteviol allows intracellular calcium to escape. The results indicate that a decrease of [Ca (2+)]i in A7r5 cells by isosteviol is mainly mediated by the selective opening of potassium (ATP) channel or/and calcium-activated potassium (SK (Ca)) channel channel. Alteration in the potassium voltage-gated (Kv) channels also plays a critical role in the inhibitory action of isosteviol. Planta Med. 2004 Feb;70(2):108-12 Stevioside Helps Hypertension: In an earlier DB PC study of 106 Taiwanese hypertensives, 250 mg (1/4 teaspoon) 3 times a day was effective throughout the one year study and lowered the average systolic from 166 to 152 and the diastolic from 104 to 90. No side-effects were noted and it had no impact on blood biochemistry or glucose. A double-blind placebo-controlled study of the effectiveness and tolerability of oral stevioside in human hypertension. Chan P, Tomlinson B, Chen YJ, Liu JC, Hsieh MH, Cheng JT. Br J Clin Pharmacol. 2000 Sep;50(3):215-20. Ed: 250 mg of pure stevioside is enough to sweeten 4-8 cups of tea. I found taking the 1/4 teaspoon dose of powdered stevioside easily tolerated if immediately followed by food and drink. At the best price I could find to get this dosage, it would cost just $0.08 per day. Several generic medicines, e.g. the ACE inhibitors captopril (Capoten) or enalaprilat (Vasotec), the diuretic hydrochlorothiazide, and some beta-blockers, for high blood pressure cost only 2-10 cents a day wholesale, but the pharmacy fee would make them more expensive than stevioside. Stevioside, if used in place of an artificial sweetener, is less expensive than any currently on the market in the U.S. Coenzyme Q10 is better researched than stevioside and costs 30-60 cents per day for 100-120 mg once a day dose. CoQ 10 is also a very good supplement for the heart. Both can be used together. Stevioside May Be Good for Diabetics: Stevioside has been used for the treatment of diabetes in Brazil. In a DB PC crossover study of a single dose of 1 g (1 teaspoon) of stevioside with a standard meal, type 2 diabetic patients, stevioside reduced the incremental area under the glucose response curve by 18% (P =.013). The insulinogenic index (AUC(i,insulin)/AUC(i,glucose)) was increased by approximately 40% by stevioside compared to control (P <.001). Stevioside tended to decrease glucagon levels, while it did not significantly alter the area under the insulin, glucagon-like peptide 1, and glucose-dependent insulinotropic polypeptide curves. Thus, stevioside reduces postprandial blood glucose levels in type 2 diabetic patients, indicating beneficial effects on the glucose metabolism and for type 2 diabetes. Antihyperglycemic effects of stevioside in type 2 diabetic subjects. Gregersen S, Jeppesen PB, Holst JJ, Hermansen K. Aarhus University Hospital, Denmark. Metabolism. 2004 Jan;53(1):73-6. Rat studies also find both anti-hypertensive and anti-hyperglycemic effects from stevioside. Metabolism. 2003 Mar;52(3):372-8. |