Ginseng

Ginseng is appearing in some 'energy drinks' and in some vitamin supplements.
What is it and does it confer any health benefits or risks?

Asian/Korean ginseng (or Panax Ginseng) has been a part of Chinese medicine for over 2,000 years. The first reference to the use of Asian ginseng dates to the 1st century A.D. The botanical name Panax means "all-heal" in Greek, and was applied to this genus because Linnaeus (Swedish botanist, 1775) was aware of its wide use in Chinese medicine. Ginseng is commonly used by elderly people in the Orient to improve mental and physical vitality.

There are three different herbs commonly called ginseng: Asian or Korean ginseng (Panax ginseng) , American ginseng (Panax quinquefolius) , and Siberian “ginseng” ( Eleutherococcus senticosus ). The latter herb is actually not ginseng at all.

Asian (Panax) ginseng is a perennial herb with a taproot resembling the shape of the human body. It grows in northern China, Korea, and Russia. The rhizome is most often available in dried form, either in whole or sliced form. Ginseng leaf, although not as highly prized, is sometimes also used mainly in energy drinks, functional foods or herbal teas; as with the rhizome it is most often available in dried form.
Commission E is a German government regulatory agency composed of scientists, pharmacists, toxicologists, physicians and herbalists that produce a series of evidence based documents known as herbal monographs. These are formal reviews of medicinal herbs based on the available scientific evidence as well as evidence from traditional use, case studies and the experience of modern herbalists. These monographs are considered to provide authoritative information, including approved uses of the herbs and their side effects, interactions and doses. What does Commission E say about ginseng? It approves its use for fatigue, debility, declining capacity for work and concentration and during convalescence. It may also be beneficial in prediabetes and diabetes (see below).
Ginseng’s actions in the body are thought to be due to a complex interplay of constituents. The primary group are the ginsenosides, which are believed to counter the effects of stress and enhance intellectual and physical performance. Thirteen ginsenosides have been identified in Asian ginseng. Two of them, ginsenosides Rg1 and Rb1, have been closely studied. Other constituents include the panaxans, which may help lower blood sugar, and the polysaccharides (complex sugar molecules), which are thought to support immune function.

Cognition booster (Level of evidence grade =B, see below ): There have been 10 human trials showing clear impovements in memory, concentration and mental performance when subjects took 200-400mg Korean ginseng extract (standardised to contain 4% ginsenosides, 100mg capsule equal to 500g root). Half of these studies were well designed double-blind placebo controlled trials.
Blood sugar regulation (Level of evidence grade =B, see below ) The hypoglycaemic effects of Korean ginseng have been acknowledged for over 30 years. Ginseng has been shown to increase insulin release from pancreatic beta-cells, increase metabolic rate and glucose transport and reduce the rate of glucose absorption and glycogenolysis.
Four double-blind placebo controlled studies (limited by small numbers of subjects of less than 50) have shown than ginseng can lower fasting blood glucose and glycated haemoglobin (HbA1c - a measure of long term sugar control), lower body weight and elevate mood and psychophysical performance. A recent study by Vuksan V et al., (Ginseng improves glucose and insulin regulation in well-controlled, type 2 diabetes: results of a randomised double-blind, placebo controlled study of efficacy and safety. Nutr Metab Cardiovasc Dis 2006; Jul 21) supports the use of ginseng in improving metabolic control in diabetic patients receiving dietary advice or antidiabetic medications. Patients who received the ginseng maintained good glycaemic control and demonstrated improved plasma glucose and insulin sensitising effect. This was especially true of the oral glucose tolerance test outcomes. The net effect was reflected in a 33% increase in both fasting and postprandial insulin sensitivity indices despite half the participants taking medications concomitantly. The authors conclude that ginseng may provide additional benefit in the management of type 2 diabetes and without the previously cited concerns relating to blood pressure or haemostatic changes.

Safety: Used in the recommended amounts (standardised extracts 200-400mg/day or nonstandadised extract of 1-4g dried root/day) ginseng is generally safe. In rare instances, it may cause over-stimulation and possibly insomnia. Consuming caffeine with ginseng increases the risk of over-stimulation and gastrointestinal upset. People with uncontrolled high blood pressure should use ginseng cautiously. Long-term use of ginseng may cause menstrual abnormalities and breast tenderness in some women. Ginseng is safe for pregnant or breast-feeding women. Long term use must not exceed 1g/day. Commission E advise that Korean Ginseng can be used continually for up to 3 months, with a repeat course if necessary.
Ginseng can interact with some medications: antidepressants, warfarin, ticlopidine or blood thinners, insulin/ medication to lower blood glucose (ginseng may lower sugar levels unpredictably)

Before commencing supplemental Ginseng consult a doctor or nutritionist (who have an interest in herbs) for advice.

More evidence based information on Panax Ginseng http://kroger.staywellsolutionsonline.com/integrativemed/

Level of evidence grades
A (Strong Scientific Evidence)
Statistically significant evidence of benefit from >2 properly randomized trials (RCTs), OR evidence from one properly conducted RCT AND one properly conducted meta-analysis, OR evidence from multiple RCTs with a clear majority of the properly conducted trials showing statistically significant evidence of benefit AND with supporting evidence in basic science, animal studies, or theory.

B (Good Scientific Evidence)
Statistically significant evidence of benefit from 1-2 properly randomized trials, OR evidence of benefit from >1 properly conducted meta-analysis OR evidence of benefit from >1 cohort/case-control/non-randomized trials AND with supporting evidence in basic science, animal studies, or theory.

C (Unclear or conflicting scientific evidence)
Evidence of benefit from >1 small RCT(s) without adequate size, power, statistical significance, or quality of design by objective criteria,* OR conflicting evidence from multiple RCTs without a clear majority of the properly conducted trials showing evidence of benefit or ineffectiveness, OR evidence of benefit from >1 cohort/case-control/non-randomized trials AND without supporting evidence in basic science, animal studies, or theory, OR evidence of efficacy only from basic science, animal studies, or theory

D (Fair Negative Scientific Evidence)
Statistically significant negative evidence (i.e., lack of evidence of benefit) from cohort/case-control/non-randomized trials, AND evidence in basic science, animal studies, or theory suggesting a lack of benefit.

F (Strong Negative Scientific Evidence)
Statistically significant negative evidence (i.e. lack of evidence of benefit) from >1 properly randomized adequately powered trial(s) of high-quality design by objective criteria.*

Lack of Evidence† - Unable to evaluate efficacy due to lack of adequate available human data

*Objective criteria are derived from validated instruments for evaluating study quality, including the 5-point scale developed by Jadad et al., in which a score below 4 is considered to indicate lesser quality methodologically (Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ, McQuay HJ. Assessing the quality of reports of randomized clinical trials: is blinding necessary? Controlled Clinical Trials 1996; 17[1]:1-12).
† Listed separately in monographs in the "Historical or Theoretical Uses which Lack Sufficient Evidence" section.