Study on North American ginseng

Dear Editor,

As a regular contributor to the ‘Summaries and Commentaries’ section of this journal I have often benefited from the insightful assessments and advice of my fellow contributors.

I have noted also that a lack of response from publication authors is not uncommon. I was therefore alarmed and disappointed at the recent ‘Author’s reply’ to the commentary regarding a publication promoting a proprietary extract of North American ginseng (Panax quinquefolius) [FACT, March 2006; 11(1): 19–21]. As one long involved in ginseng study and familiar with the extract in question (80% polysaccharide), I was surprised to learn from the text of the reply that ‘Numerous clinical and experimental studies have consistently shown that this proprietary product has the potential to enhance immune systems.^1–7’ Upon examination of the list of references I discovered what I already knew, that only one other study¹ had evaluated the immunomodulating activity of this extract, Cold-fX (code name CVT-E002). The other six references concerned Panax ginseng (Asian ginseng), four of which dealt with isolated polysacchar-ides and one with immunomodulatory effects of two extracts of P. ginseng.