Evaluation of the ergogenic properties of ginseng - An update

Ginseng has been used in the Orient for several thousand years as an 'adapt ogenic' as well as a 'restorative' agent. It has been used to treat nervous disorders, anaemia, wakefulness, dyspnoea, forgetfulness and confusion, pr olonged thirst, decreased libido, chronic fatigue, angina and nausea. Altho ugh the mechanisms underlying the alleged effects of ginseng remain to be e lucidated, there is an extensive animal literature dealing with the effects of ginseng on the cardiovascular system, central nervous system, endocrine system, metabolism, and immune system. In our previous review dealing with the efficacy of ginseng, we concluded that while studies with animals show that ginseng, or its active components, may prolong survival to physical o r chemical stress, there is generally a lack of controlled research demonst rating the ability of ginseng to improve or prolong performance in fatigued humans. In this review, we extend our earlier analysis on the potential ef ficacy of ginseng use in the enhancement of physical performance and modifi cation of fatigue slates. Our analysis reveals that published literature ap pearing since our earlier review has not resolved the equivocal nature of r esearch evidence involving animals or humans. Also, the lack of unanimity i n this research can be explained on the basis of various methodological pro blems such as inadequate sample size and lack of double-blind, control and placebo paradigms. In addition, the absence of acceptable approaches to the problem of 'sourcing', in concert with an absence of compliance data in hu man research, further complicates the interpretation of this research liter ature, Nevertheless, the use of ginseng continues to grow, and current sale s are estimated to he over %US300 million annually. There is clearly a need for systematic research dealing with the efficacy of ginseng, and this res earch needs to take into account basic, fundamental design considerations i f there is to be any hope of establishing whether or not ginseng possesses efficacy.