|
Researchers from various academic and research institutions within Canada and South Korea recently conducted a small, randomized clinical trial to assess the viability of Korean red ginseng (Panax ginseng) as an adjunct treatment in well-controlled type-2 diabetes and found some beneficial effects.1
The study was part of a broader Korean red ginseng testing program. It was preceded by sequential, acute, screening studies of Korean red ginseng, to determine the best treatment protocol.2 This screening process identified the preparation (Korean red ginseng rootlets), dose (2g per meal = 6g per day), and the mode of administration (pre-prandial, taken 40 minutes prior to a meal) applied with success in the present study.
Nineteen patients completed the randomized, placebo-controlled, double-blind, crossover trial.1 Participants began the trial by taking the placebo (vanilla-flavored 500 mg capsules containing cornstarch) for 4 weeks to generate baseline data. Participants were then assigned either 6 g per day of encapsulated Korean red ginseng rootlets (Korea Ginseng Manufacturing Plant, National Agricultural Cooperative Federation, Chung-buk, Korea) or the placebo following the treatment protocol identified above for 12 weeks. The participants were next “washed out” on placebo over 4 to 6 weeks. Finally, they were crossed over to the alternate therapy (i.e., those patients previously given the ginseng were given placebo and vice versa) for another 12 weeks of treatment. Patients kept dietary records during the trial and reported to a clinic every 6 weeks for lab tests. While participating in this trial, patients also managed their diabetes through diet or through diet plus oral agents (sulfonylurea, metformin, rosiglitazone, acarbose, or a combination of these).
Results of the trial showed that the Korean red ginseng preparation did not significantly affect patients’ long-term glycemic control as assessed by HbA1c (a lab test that shows the average amount of glucose that has been in a person’s blood over the last 2 to 3 months), which was the primary, measured endpoint of the trial. But according to the authors of this trial, patients maintained very good glycemic control throughout. The authors explain that this may have been due to the glycemic control patients had already achieved through their underlying diabetes therapies, and they claim that significant decreases in blood sugar levels may have been more likely detected in patients with poorly controlled type-2 diabetes.
Despite lack of an observed effect on the primary endpoint, HbA1c, the ginseng treatment did significantly improve plasma glucose and plasma insulin regulation. According to the trial’s authors, this indicates that patients with type-2 diabetes might derive additive benefits to postprandial (after eating) carbohydrate metabolism by taking the Korean red ginseng preparation as an adjunct treatment. Furthermore, the ginseng treatment did not appear to affect patients’ blood pressure levels, even though they consumed more sodium than patients taking placebo. According to the authors, this may indicate a possible blood pressure-reducing effect of Korean red ginseng, which could have been masked by the blood pressure-raising effect of the sodium. The authors write, “This demonstrated safety is noteworthy, as reviews have consistently warned of adverse effects of ginseng that include impaired haemostatic function and elevated blood pressure.”1
The researchers pointed out that certain caveats complicate interpretation of their findings. In particular, the high number of trial dropouts (from 39 to 19) and the resulting small sample size may have impacted the results. Also, because the patients who completed the trial had particularly well-controlled diabetes symptoms, they might not represent typical candidates for adjunctive treatment. The results from the ginseng preparation used in this trial, meanwhile, might not be duplicated by other doses, preparations, or batches of Korean red ginseng.
Korean red ginseng is actually the standard white ginseng that is steamed when it is still fresh, the steaming process turning the roots and rootlets to a reddish, auburn color, and causing some changes in the roots’ chemistry. Korean red ginseng roots and advanced products (capsules, tablets, teas, extracts) are controlled by the Korean government’s Office of Monopoly while white, unsteamed ginseng roots and products are sold via commercial companies.
-Courtney Cavaliere
References
1. Vuksan V, Sung MK, Sievenpiper JL, Stavro PM, Jenkins AL, Di Buono M, Lee KS, Leiter LA, Nam KY, Arnason JT, Choi M, Naeem A. Korean red ginseng (Panax ginseng) improves glucose and insulin regulation in well-controlled type 2 diabetes: results of a randomized, double-blind, placebo-controlled study of efficacy and safety. Nutrition, Metabolism & Cardiovascular Diseases. In press. [Epub July 21, 2006]
2. Sievenpiper JL, Sung MK, Di Buono M, Seung-Lee K, Nam KY, Arnason JT, Leiter LA, Vuksan V. Korean red ginseng rootlets decrease acute postprandial glycemia: results from sequential preparation- and dose-finding studies. J Am Coll Nutr. 2006 Apr;25(2):100-7.
|