Slowing the Progression of Alzheimer's Disease Using Panax Ginseng. What the Science Says.

Most people have probably heard of ginseng before. In fact it is often added to energy drinks and sport supplements to enhance stamina and endurance. For those that aren't familiar with it ginseng is used to refere to any of 4 different plant species used in traditional medicines as adaptogens. "What the hell is an adaptogen?" I hear you ask. Well basically an adaptogen is traditionally a herb or supplement that helps the mind and body adapt and cope with stressful situations. The four types of ginseng are commonly referred to by there geographical location and include Korean, Siberian, American and Indian. All of them are very interesting herbs however for this post we will concentrate on Korean ginseng (Panax Ginseng) as it is probably the most extensively studied.

So the big question here is does Panax Ginseng have any anti-Alzheimer's activity? The answer to that question appears to be yes. In a 2008 study by Lee et al Alzheimer's patients were assigned either a ginseng supplement or a placebo. The supplement consisted of 4.5g per day of Panax Ginseng root powder and was given to 58 patients. The placebo was given to 39 patients. The study lasted for 24 weeks (12 weeks of supplementation followed by 12 weeks without). Cognitive performances were monitored using the mini-mental state examination (MMSE) and Alzheimer disease assessment scale (ADAS). After ginseng treatment, the cognitive subscale of ADAS and the MMSE score began to show improvements and continued up to 12 weeks. After discontinuing ginseng, the improved ADAS and MMSE scores declined to the levels of the control group. This demonstrated that panax ginseng may be effective in not just halting the progression of Alzheimer's disease but even reversing some of its effects (At least over a 12 week period). These results were confirmed by another study by Heo et al. They essentially repeated the above study and also used a 9g dose of panax ginseng root powder. This 9g dose was shown to improve cognitive measures in the Alzheimer's patients compared to the placebo group. Both of these studies show a lot of promise however larger studies would be required to really confirm these benefits. So for now what other evidence can we find for and against panax ginseng?

There are more clues as to how panax ginseng could be beneficial for Alzheimer's disease sufferers. Firstly it appears to be neuroprotective by preventing neurons from undergoing programmed cell death (apotosis). Two studies, one animal and cellular (1, 2), demonstrate how administration of panax ginseng can protect neurons from dying when exposed to stressful and damaging environments. In addition to this a cellular study on rat brains (3) showed that addition of panax ginseng saponins could reduce the functional defects caused by beta amyloid accumulation in and around neurons. These researchers followed up this study by injecting beta amyloid into the brains of rats to induce Alzheimer's like symptoms of amnesia (4). Chronic administration of ginseng saponins was shown to significantly reverse the amnesia caused by the beta amyloid confirming the results from the first study only in a working animal model. It is not yet understood how the panax ginseng reverses neuronal defects caused by beta amyloid. It is clear that ginseng did not eliminate the beta amyloid and so its effects must have occurred through a different mechanism. This is useful to know as it points to another possible mechanism by which to attack Alzheimer's disease. For the time being panax ginseng is a promising potential treatment for Alzheimer's disease and in combination with other strategies or supplements could indeed be very complimentary.

1. Neuroprotective effects of ginseng total saponin and ginsenosides Rb1 and Rg1 on spinal cord neurons in vitro. Liao B, Newmark H, Zhou R, Experimental Neurology [2002, 173(2):224-234]
2. Panax ginseng ginsenoside-Rg2 protects memory impairment via anti-apoptosis in a rat model with vascular dementia. Guizhi Zhang, Ailing Liu, Yingbin Zhou, Xun San, Taowei Jin, Yi Jin. Journal of Ethnopharmacology, Volume 115, Issue 3, 12 February 2008, Pages 441–448
3. Effect of ginseng saponins on beta-amyloid-suppressed acetylcholine release from rat hippocampal slices. Lee TF, Shiao YJ, Chen CF, Wang LC. Planta Med. 2001 Oct;67(7):634-7.
4. Reductions in levels of the Alzheimer's amyloid beta peptide after oral administration of ginsenosides. Chen F, Eckman EA, Eckman CB. FASEB J. 2006 Jun;20(8):1269-71.