The National Academy of Science has published the results of a study that found that *Withania somniferaf aka "Ashwagandha" reverses Alzheimer's disease (AD) in mice with no noted side effects.

While it can be argued that just because it reverses AD in mice it doesn't necessarily mean that it will work in humans, I'm still surprised that it isn't being broadly recommended for people to try, especially since it is so cheap.

If you read the comments, which of course are anecdotal, people have been taking this herb for brain function and are enthusiastic about the results.

Are there any medical reasons why isn't this being promoted more for the prevention and reversal of AD by?

1 Answer 1


You should read the article carefully. In the Introduction section they give some insight for their study:

The majority of AD cases are sporadic in nature. The small fraction of familial cases are caused primarily by mutations in three genes: amyloid precursor protein (APP), presenilin1 (PS1), and presenilin 2 (PS2).

They clearly specify what they are investigating:

Here we demonstrate that a WS extract reverses behavioral deficits and plaque pathology and reduces the Aβ burden in middle-aged and old APP/PS1 mice through up-regulation of liver LRP, leading to increased clearance of Aβ.

So they are investigating the effects of this herb in mice which are "diagnosed" with familial Alzheimers disease (AD).

Less than 0.1% of all cases of AD are familial (Lancet).

The sad thing is that we have no possibility whatsoever to tell whether a patient have the familial type AD. Let´s make a wild assumption that this herb would actually reverse AD in 1% of patients with familial AD (This 1% we would be remarkable in this context). We need to treat 100,000 patients with AD to reverse it in one patient. That kind of "treatment" would not be feasible at all.

Moreover, there are probably hundreds or thousands herbs and drugs which have shown promising results in animals. Unfortunately, >99% of these molecules and potential drugs fail to work in humans. This is due to facts that our fundamental understanding in disease processes are poor and the complexity of the diseases are so overwhelming that the proposed mechanism of recovery observed in the animal subjects with "artificial" diseases just don´t work similarly in human subjects.

  • Here is another study where the inquiry is not limited to familial: ncbi.nlm.nih.gov/pmc/articles/PMC3897003
    – Ruminator
    Aug 9, 2015 at 16:58
  • Here it is identified for treating Huntington's Disease and to improve cognition: ncbi.nlm.nih.gov/pmc/articles/PMC3841999 My OP relates to "why not give it a try"?
    – Ruminator
    Aug 9, 2015 at 17:05
  • 2
    @WoundedEgo In your OP you talk about reversing alzheimer. Your first study is about cognitive boost in healthy humans, second study is about whole another disease. They are out of context in this question.
    – arkiaamu
    Aug 9, 2015 at 18:17
  • "I'm still surprised that it isn't being broadly recommended for people to try, especially since it is so cheap". It has a good track record of helping with brain function and has reversed AD in mice (one type) so while there is no smoking gun here, I'm taking it!
    – Ruminator
    Aug 9, 2015 at 19:29
  • I think there are some other things at play here. Where would one buy naturally AD mice? Transgenic mice would be easy to come by. Also, a full blown human trial that meets FDA approval apparently costs over a billion dollars. If they got fast track (and half of drugs do, bypassing trial stage IV) it would still cost almost half of that but there would not be the billions of profit because it is a cheap herb.
    – Ruminator
    Aug 10, 2015 at 18:42

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