SR9073 - The Effect of Ontario-Grown American Ginseng on Blood Pressure Control in Hypertension

Lead researcher

Dr. Vladimir Vuksan, Risk Factor Modification Centre, St. Micahel's Hospital

Objectives

To determine if American ginseng can reduce blood pressure and improve endothelial function in individuals with hypertension.

Expected benefits

If American ginseng reduces blood pressure and improves endothelial function in individuals with hypertension, the demand for American ginseng in the North American market could greatly increase.

Results

The use of ginseng in individuals with high blood pressure has been a controversial topic. Some commentaries in the medical literature have mentioned that ginseng could increase the level of a person's blood pressure. However, this has never been shown to be the case in a properly designed study in humans called a randominized-controlled-trial. In this type of study, participants are assigned to consume treatments randomly (like a coin-toss) and the effect of a treatment on a given parameter is compared to the effect of a placebo(inactive agent) on this same parameter.

Through this type of study, our research team at St. Michael's Hospital in Toronto previously showed that American ginseng - a popular type of ginseng that grows predominantly in Ontario - actually lowered blood pressure when individuals with type 2 diabetes consumed it for 8 weeks. Considering these findings, we decided to test the effect of American ginseng on blood pressure in individuals that have high blood pressure, but not type 2 diabetes. High blood pressure is a disease that currently afflicts over 20% of the North American population, and since many of these individuals could use ginseng at one time or another, it is important to know how this herb affects blood pressure.

We investigated how consumption of 3 grams per day of American ginseng for 12-weeks could affect blood pressure in 30 individuals with high blood pressure. We also tested how consumption of 3 grams per day of placebo - cornstarch - for 12-weeks affected blood pressure in these same individuals During the study period all participants kept their medications, dietary, and exercise habits constant, and also did not change their body weight. These are factors that have also been shown to affect blood pressure.

The findings of our study showed that consumption of American ginseng compared with consumption of placebo had no effect on blood pressure in the 30 individuals with hypertension. Based on this, it can be said that American ginseng is safe for use by individuals who have hypertension.

Related information

• Other projects funded through the New Directions Research Program in 2001