Viral Upper Respiratory Infections (Colds and Influenza) and Ginseng

Although most people in the West think of ginseng as a stimulant, in Eastern Europe ginseng is widely believed to improve overall immunity to illness. Contrary to popular belief, echinacea does not seem to prevent respiratory infections, but research suggests that the regular use of ginseng might help prevent colds and flus.

There are three different herbs commonly called ginseng: Asian or Korean ginseng (Panax ginseng), American ginseng (Panax quinquefolius), and Siberian "ginseng" (Eleutherococcus senticosus), which is not true ginseng.

The exact effect of ginseng on colds and flu is not clear, but it probably helps prevent these illnesses by supporting the immune system's overall function.

Read more details about Ginseng.

A double-blind, placebo-controlled study of 323 people found meaningful evidence that an extract of American ginseng taken at 400 mg daily may help prevent the common cold.¹⁵¹ Participants who used the extract over 4 months experienced a reduced number of colds as compared to those taking the placebo. Comparative benefits were also seen regarding the percentage of participants who developed two or more colds, and the severity and duration of cold symptoms that did develop. Similar benefits were also seen in a study of 43 people.¹⁵²

Two double-blind, placebo-controlled studies enrolling a total of about 100 people indicate that American ginseng may also help prevent flu-like illness in seniors.¹²³

The typical recommended daily dosage of Panax ginsengis is 1 g to 2 g of raw herb, or 200 mg daily of an extract standardized to contain 4% to 7% ginsenosides. In one study of American ginseng (Panax quinquefolius) for diabetes, the dose used was 3 g daily.³⁸ Studies on the use of ginseng for preventing colds and flu have featured daily doses such as 100 mg and 400 mg of ginseng extract.

Note: Ginsenosides are the active compounds in ginseng. There are dozens of ginsenosides in ginseng. Because different ginsenosides have different effects, two different ginseng products with similar totalginsenoside content will not necessarily have similar efficacy. Unfortunately, current scientific knowledge does not allow us at present to make informed recommendations on which specific ginsenosides are useful for which conditions.

Ordinarily, a 2- to 3-week period of using ginseng is recommended, followed by a 1- to 2-week “rest” period. Russian tradition suggests that ginseng should not be used by those under 40. However, there is no scientific evidence to support these recommendations.

A number of different health practitioners, including physicians, naturopathic doctors, Chinese medicine doctors, and herbalists, might be knowledgeable about and recommend the use of ginseng for common ailments such as cold and flu.

Safety Issues

Ginseng appears to be nontoxic, both in the short- and long-term, according to the results of studies in mice, rats, chickens, and dwarf pigs. ^{1 2 3} Reported side effects are rare. There are a few case reports of breast tenderness, postmenopausal vaginal bleeding, and menstrual abnormalities associated with Panax ginsenguse. ^{4 5 6 7} Such side effects suggest that it has estrogenic properties. However, a large double-blind trial of Panax ginsengfound no estrogen-like effects. ⁸ Another double-blind trial found no effects on estrogen or testosterone, ⁹ and a carefully designed test-tube study showed that ginseng is not estrogenic. ¹⁰ Therefore, it is possible that these apparent side effects were coincidental; another possibility is that adulterants in the ginseng product used caused the problem. Ginseng and other Asian herbal products have often been found to contain unlisted herbs and pharmaceuticals. ¹¹ Estrogen itself stimulates the growth of breast cancer cells. Interestingly, in a test-tube study, Panax ginsengwas again found to be non-estrogenic, and yet it nonetheless stimulated the growth of breast cancer cells. ¹² Although the mechanism of this effect is not known, the results suggest that women who have had breast cancer should avoid using ginseng.

Unconfirmed reports suggest that highly excessive doses of Panax ginsengcan cause insomnia, raise blood pressure, increase heart rate, and possibly cause other significant effects. Whether some of these cases were actually caused by caffeine mixed in with ginseng remains unclear. One double-blind study failed to find any effect on blood pressure. ¹³ One case report and one double-blind trial suggest that Panax ginsengcan reduce the anticoagulant effects of Coumadin (warfarin), ¹⁴ but another trial failed to find such an interaction. ¹⁵ The reason for this discrepancy is not clear, but prudence would nonetheless suggest not combining ginseng and warfarin.

Two reports indicate that combination treatment with Panax ginsengand antidepressant drugs may result in a manic episode. ¹⁶ There are also theoretical concerns regarding use of ginseng by people with diabetes. If it is true, as the preliminary studies discussed above suggest, that ginseng can in fact reduce blood sugar levels, people with diabetes who take ginseng might need to reduce their dose of medication. On the other hand, if certain types of ginseng have the opposite effect (as researchers hypothesize), this could necessitate an increase in medication. The bottom line: people with diabetes should only use ginseng under physician supervision.

In 1979, an article was published in the Journal of the American Medical Associationclaiming that people can become addicted to Panax ginsengand develop blood pressure elevations, nervousness, sleeplessness, diarrhea, and hypersexuality. ¹⁷ However, this report has since been thoroughly discredited and should no longer be taken seriously. ¹⁸ Chinese tradition suggests that Panax ginsengshould not be used by pregnant or nursing mothers, and one animal study hints that ginseng use by a pregnant mother could cause birth defects. ¹⁹ Safety in young children or people with severe liver or kidney disease has not been established.

Interactions You Should Know About

If you are taking:

• Antidepressants: Panax ginsengmight cause manic episodes.

• Insulin or oral hypoglycemics : Various forms of ginseng may unpredictably alter your dosage need.

• Coumadin ( warfarin ): Panax ginsengmight possibly decrease its effect.

• Influenza vaccine : Panax ginsengmight help it work better.

1. Baldwin CA, Anderson LA, Phillipson JD. What pharmacists should know about ginseng. Pharm J. 1986;237:583-586.
2. Hess FG Jr, Parent RA, Cox GE, Stevens KR, Becci PJ. Reproduction study in rats or ginseng extract G115. Food Chem Toxicol. 20(2):189-92.
3. Newall C, Anderson LA, Phillipson JD. Herbal Medicines: A Guide for Health-Care Professionals. London: Pharmaceutical Press; 1996:143,148.
4. Fugh-Berman A. Herb-drug interactions. Lancet. 355(9198):134-8.
5. Greenspan EM Ginseng and vaginal bleeding [letter]. JAMA. 1983;249:2018.
6. Hammond TG, Whitworth JA Adverse reactions to ginseng [letter]. Med J Aust. 1981;1:492.
7. Palmer BV, et al. Gin Seng and mastalgia [letter]. Br Med J. 1978;1:1284.
8. Wiklund IK, Mattsson LA, Lindgren R, Limoni C. Effects of a standardized ginseng extract on quality of life and physiological parameters in symptomatic postmenopausal women: a double-blind, placebo-controlled trial. Swedish Alternative Medicine Group. Int J Clin Pharmacol Res. 19(3):89-99.
9. Forgo I, Kayasseh L, Staub JJ. Effect of a standardized ginseng extract on general well-being, reaction time, lung function and gonadal hormones [in German]. Med Welt. 1981;32:751-756.
10. Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs, and spices. Proc Soc Exp Biol Med. 217(3):369-78.
11. Newall C, Anderson LA, Phillipson JD. Herbal Medicines: A Guide for Health-Care Professionals. London: Pharmaceutical Press; 1996:143,148.
12. Amato P, Christophe S, Mellon PL. Estrogenic activity of herbs commonly used as remedies for menopausal symptoms. Menopause. 9(2):145-50.
13. Stavro PM, Woo M, Leiter LA, Heim TF, Sievenpiper JL, Vuksan V. Long-term intake of North American ginseng has no effect on 24-hour blood pressure and renal function. Hypertension. 47(4):791-6.
14. Janetzky K, Morreale AP. Probable interaction between warfarin and ginseng. Am J Health Syst Pharm. 54(6):692-3.
15. Jiang X, Williams KM, Liauw WS, Ammit AJ, Roufogalis BD, Duke CC, Day RO, McLachlan AJ. Effect of St John's wort and ginseng on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects. Br J Clin Pharmacol. 57(5):592-9.
16. Jones BD, Runikis AM. Interaction of ginseng with phenelzine. J Clin Psychopharmacol. 7(3):201-2.
17. Siegel RK. Ginseng abuse syndrome. Problems with the panacea. JAMA. 241(15):1614-5.
18. Tyler VE. Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York, NY: Pharmaceutical Products Press; 1994.
19. Chan LY, Chiu PY, Lau TK. An in-vitro study of ginsenoside Rb1-induced teratogenicity using a whole rat embryo culture model. Hum Reprod. 18(10):2166-8.

38. Vuksan V, Sievenpiper JL, Koo VYY, et al. American ginseng (Panax quinquefolius L.) reduces postprandial glycemia in nondiabetic subjects and subjects with type 2 diabetes mellitus. Arch Intern Med. 2000;160:1009-1013.
123. McElhaney JE, Gravenstein S, Cole SK, et al. A placebo-controlled trial of a proprietary extract of North American ginseng (CVT-E002) to prevent acute respiratory illness in institutionalized older adults. J Am Geriatr Soc. 2004;52:13-19.
151. Predy GN, Goel V, Lovlin R, et al. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial. CMAJ. 2005;173:1043-1048.
152. McElhaney JE, Goel V, Toane B, et al. Efficacy of COLD-fX in the prevention of respiratory symptoms in community-dwelling adults: a randomized, double-blinded, placebo controlled trial. J Altern Complement Med. 2006;12:153-7.