Review of American Ginseng
- What is American Ginseng?
- Who Should Consider Taking American Ginseng?
- Summary of American Ginseng's Physiological Effects
- American Ginseng Research
- Is American Ginseng effective?
- How to take American Ginseng
- American Ginseng References
American ginseng (Panax quinquifolium) is chemically similar to Chinese, or Korean ginseng. It is distributed across eastern and central USA and Canada. Ginseng contains a number of active ingredients – in particular steroid glycosides (Hsu et al., 2005). Like other types of ginseng it is believed to act as a tonic that enhances fatigue resistance, boosts the immune system, stimulates appetite, and improves mental and physical stamina. Recent research suggests it may help to prevent colds, improve glucose tolerance, reduce muscle damage, and even improve the symptoms of attention deficit disorder (ADHD).
American ginseng appears to be of benefit to people looking to reduce the risk of chest infections, improve glucose tolerance, reduce muscle damage during exercise, improve recovery from exercise, and enhance mental function.
- Enhances immune function
- Reduces the risk of contracting a cold, reduces the severity of symptoms and length of cold
- Protects against excessive increases in blood sugar levels
- Reduces the level of muscle damage following exercise
- Acts as a potent antioxidant that protects against damage to important cell structures
- May enhance memory and could be of benefit in the treatment of ADHD
- Appears to be safe with few side effects
North American ginseng has been shown to enhance a number of immune functions including: immunogloblin production by lymphocytes, increase phagocytosis, and natural killer cell cytotoxicity (Predy et al., 2005).
Recent research has demonstrated that the consumption of just 200mg, twice daily, of American ginseng extract reduced the risk of contracting acute respiratory illness by 89% (McElhaney et al., 2004).
A recent large scale study, involving 323 subjects, demonstrated that the consumption of American ginseng (2x200mg of standardized extract) reduced the number of colds experienced by subjects by 28%, the number of recurrent colds by 56%, reduced the number of days that cold symptoms were experienced from 16.5 to 10.8 days, and the severity of symptoms by 31% (Predy et al., 2005). The researchers concluded that the standardized extract reduced the absolute risk of colds, mean number of colds per person, and appeared to be safe for normal use.
A number of studies have demonstrated that American ginseng protects against excessive increases in blood sugar levels (Vuksan et al., 2000a; Vuksan et al., 2000b; Vuksan et al., 2001). People who have naturally high blood sugar levels – like diabetics – are at an increased risk of cardiovascular disease (CVD) (Vuksan et al., 2000a). But, even non-diabetic subjects who have elevated blood sugar levels have an increased risk of CVD (Bjornholt et al., 1999; Vuksan et al., 2000a). Therefore, maintaining blood sugar levels in non-diabetic patients is important for preventing CVD.
Research by Vuksan et al., (2000a) demonstrated that the consumption of 3g of American ginseng, 40-120 minutes before the ingestion of 25g of glucose, significantly improved glucose tolerance in non-diabetic subjects. This led to significant reductions in blood glucose levels, 30-60 minutes after the ingestion of glucose. The researchers concluded that American ginseng may represent an important approach to delaying the onset of diabetes mellitus and CVD. Further research by Vuksan et al., (2000b) found that American ginseng works effectively for people with type II diabetes mellitus.
Recent research looking at the effects of 4-weeks of American ginseng supplementation on exercise performance, found reduced levels of creatine kinase (a key indicator of muscle damage), following aerobic exercise, indicating reduced levels of muscle damage following supplementation (Hsu et al., 2005). Blood lactate levels were also lower during a submaximal run at 80% VO2max. The researchers concluded that the reduction in blood CK levels may be due to decreased muscle cell damage. Therefore, American ginseng may prove useful to athletes looking to improve their rate of recovery post exercise, and to reduce the amount of muscle damage.
The researchers speculated that American ginseng may protect against muscle damage by acting as an antioxidant, reducing damage by free radicals, and inhibiting oxidation of lipids. Previous research has clearly shown that American ginseng is a potent antioxidant that protects against the damaging effects of free radicals (kitts et al., 2000a; Kitts et al., 2000b) and protects low density lipoproteins from oxidation (Li et al., 1999).
Research has also shown that American ginseng can enhance memory, and recent research demonstrates a potential to improve symptoms of ADHD when combined with Ginkgo biloba (Lyon et al., 2001).
American ginseng appears to be safe with few adverse effects (Kitts et al., 2000b; McElhaney et al., 2004; Predy et al., 2005; Starvo et al., 2005) even, 3-17 year old children, who consumed 200mg daily for 4 weeks, experienced few adverse effects (Lyon et al., 2001). It is often reported that ginseng may increase blood pressure, however, research by Starvo et al., (2005) found that although their was a slight increase in systolic blood pressure, diastolic blood pressure – which is considered the more important indicator of blood pressure – actually decreased in patients with hypertension following supplementation. The researchers found that American ginseng did not cause any significant changes in mean blood pressure in patients with raised blood pressure.
American ginseng appears to be effective at reducing the risk of infection, enhancing recovery from exercise, controlling blood sugar levels, protecting against the damaging effects of free radicals, and improving mental function.
Research suggests that the consumption of 4x400mg, daily, may reduce muscle damage after exercise. Glucose tolerance may be enhanced by consuming 3g, approximately 40 minutes before food.
Bjornholt, J. V., Erikssen, G., Aaser, E., Sandvik, L., Nitter-Hauge, S., Jervell, J., Erikssen, J. and Thaulow, E. (1999) Fasting blood glucose: an underestimated risk factor for cardiovascular death. Results from a 22-year follow-up of healthy nondiabetic men. Diabetes Care. 22, 45-49.
Hsu, C. C., Ho, M. C., Lin, L. C., su, B. and Hsu, M. C. (2005) American ginseng supplementation attenuates creatine kinase level induced by submaximal exrercise in human beings. World J Gastroenterol. 11 (34), 5327-5331.
Kitts, D. D., Wijewickreme, A. N. and Hu, C. (2000a) Antioxidant properties of North American ginseng extract. Mol Cell Biochem. 203 (1-2), 1-10.
Kitts, D and Hu, C. (2000b) Efficiacy and safety of ginseng. Public Health Nutr. 3 (4A), 473-485.
Li, J., Huang, M., Teoh, H. and Man, R. Y. (1999) Panax quinquefolium saponins protects low density lipoproteins from oxidation. Life Sci. 64, 53-62.
Lyon, R. M., Cline, J. C., Totosy de Zepetnek, J., Shan, J. J., Pang, P. and Benishin, C. (2001) Effect of herbal extract combination Panax quinquefolium and Ginkgo biloba on attention-deficit hyperactivity disorder: a pilot study. J Psychiatry Neurosci. 26 (3), 221-228.
McElhaney, J. E., Gravenstein, S., Cole, S. K., Davidson, E., O’neill, D., Petitjean, S., umbe, B. and Shan, J. J. (2004) A placebo-controlled trial of proprietary extract of North American ginseng (CVT-E002) to prevent acute respiratory illness in institutionalized older adults. J Am Geriatr Soc. 52 (1), 13-19.
Predy, G. N., Goel, V., Lovlin, R., Donner, A., Stitt, L. and Basu, T. K. (2005) Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomised controlled trial. CMAJ. 173 (9), 1043-1048.
Starvo, P. M., Woo, M., Heim, T. F., Leiter, L. A. and Vuksan, V. (2005) North American ginseng exerts a neutral effect on blood pressure in individuals with hypertension. Hypertension. 46 (2), 406-411.
Vuksan, V., Starvo, M. P., Sievenpiper, J. L., Koo, V. YY., Wong, E., Beljan-Zdravkovic, U., francis, T., Jenkins, A. L., Leiter, L. a., Josse, R. G. and Xu, Z. (2000a) American Ginseng Improves Glycemia in Individuals with Normal Glucose Tolerance: Effect of Dose and Time Escalation. J Am C Nutr. 19 (6), 738-744.
Vuksan, V., Sievenpiper, J. L., Koo, V. Y., Francis, T., Beljian-Zdravkovic, U., Xu, Z. and Vidgen, E. (2000b) American ginseng (Panax quinquefolium L.) reduces postprandial glycemia in non-diabetic subjects and subjects with type 2 diabetes mellitus. Arch Intern Med. 160 (7), 1009-1013.
Vuksan, V., Sievenpiper, J. L., Wong, J., Xu, S., Beljan-Zdravkovic, U., Arnason, J. T., Assinewe, V., Starvo, M. P., Jenkins, A. L., Leiter, L. A. and Francis, T. (2001) American ginseng (Panax quinquefolium L.) attenuates postprandial glycemia in a time-dependent but not dose-dependent manner in healthy individuals. Am J Clin Nutr. 73 (4), 753-758.