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Scientific Studies

Stress Reduction and Neural Protection from an Ancient Herb

Stress Reduction and Neural Protection from an Ancient Herb


Powerful Protective Effects on the Nervous System. Stress, environmental toxins, and poor nutrition all have a detrimental impact on our nervous systems. Scientific studies support ashwagandha’s ability not only to relieve stress, but also to protect brain cells against the deleterious effects of our modern lifestyles.

For example, in validated models of anxiety and depression, ashwagandha has been demonstrated to be as effective as some tranquilizers and antidepressant drugs. Specifically, oral administration of ashwagandha for five days suggested anxiety-relieving effects similar to those achieved by the anti-anxiety drug lorazepam, and antidepressant effects similar to those of the prescription antidepressant drug imipramine .1

Stress can cause increased peroxidation of lipids, while decreasing levels of the antioxidant enzymes catalase and glutathione peroxidase. When ashwagandha extract was administered by researchers one hour before a daily stress-inducing procedure, all of the aforementioned parameters of free radical damage normalized in a dose-dependent manner.2 Premature aging associated with chronic nervous tension may be related to increased oxidative stress, which is abolished by the potent antioxidant properties of ashwagandha extract. Researchers believe this finding supports the clinical use of ashwagandha as an anti-stress agent.

In one of the most complete human clinical trials to date, researchers studied the effects of a standardized extract of ashwagandha on the negative effects of stress, including elevated levels of the stress hormone cortisol. Many of the adverse effects of stress are thought to be related to elevated levels of cortisol. The results were impressive. The participants subjectively reported increased energy, reduced fatigue, better sleep, and an enhanced sense of well-being. The participants showed several measurable improvements, including a reduction of cortisol levels up to 26%, a decline in fasting blood sugar levels, and improved lipid profiles.

Using a validated model of damaged nerve cells and impaired nerve-signaling pathways, re-searchers noted that ashwagandha supported significant regeneration of the axons and dendrites of nerve cells. Furthermore, ashwagandha extract supported the reconstruction of synapses, the junctions where nerve cells communicate with other cells. The investigators concluded that ashwagandha extract helps to reconstruct networks of the nervous system, making it a potential treatment for neurodegenerative diseases such as Alzheimer’s.3


In another study, the researchers noted that ashwagandha helped promote the growth of both normal and damaged nerve cells, suggesting that the herb may boost healthy brain cell function as well as benefit diseased nerve cells.4

Ashwagandha also shows promise as a treatment for Parkinson’s and Alzheimer’s diseases, chronic neurodegenerative conditions for which there currently are no cures. In a recent study using a standardized model of human Parkinson’s disease, ashwagandha extract reversed all the parameters of Parkinson’s-type neurodegeneration significantly and in a dose-dependent manner.5 Remarkably, an earlier study showed that ashwagandha extract inhibits acetylcholinesterase, an enzyme responsible for breaking down one of the brain’s key chemical messengers. Drugs currently used in the treatment of Alzheimer’s disease, such as Aricept®, act in this very manner to slow the progression of this frightening, mind-robbing disease.6


Chronic stress exacts a high price from our bodies as well as our minds. Many degenerative diseases, as well as premature aging, are associated with chronic nervous tension. There is great need for safe and effective prevention strategies to combat the ravages of stress on our nervous system.

Ashwagandha, an exotic Indian herb, has demonstrated anti-anxiety and neuroprotective effects.

1. Bhattacharya SK, Bhattacharya A, Sairam K, Ghosal S. Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine. 2000 Dec;7(6):463-9.

2. Bhattacharya A, Ghosal S, Bhattacharya SK. Antioxidant effect of Withania somnifera glycowithanolides in chronic footshock stress-induced perturbations of oxidative free radical scavenging enzymes and lipid peroxidation in rat frontal cortex and striatum. J Ethnopharmacol. 2001 Jan;74(1):1-6.

3. Kuboyama T, Tohda C, Komatsu K. Neuritic regeneration and synaptic reconstruction induced by withanolide A. Br J Pharmacol. 2005 Apr;144(7):961-71.

4. Tohda C, Kuboyama T, Komatsu K. Search for natural products related to regeneration of the neuronal network. Neurosignals. 2005;14(1-2):34-45.

5. Ahmad M, Saleem S, Ahmad AS, et al. Neuroprotective effects of Withania somnifera on 6-hydroxydopamine induced Parkinsonism in rats. Hum Exp Toxicol. 2005 Mar;24(3):137-47.

6. Choudhary MI, Yousuf S, Nawaz SA, Ahmed S, Atta uR. Cholinesterase inhibiting withanolides from Withania somnifera. Chem Pharm Bull (Tokyo). 2004 Nov;52(11):1358-61.