by Marcus Ettinger DC, BSc. 10/3/07
A Potent Adaptogen
We live in a world where stress is a constant reality and has become accepted as a normal part of the western lifestyle. Stress is probably the most powerful influence on human beings just behind genetics. Stress exerts its profound effects on both our physical body and mental state. Research has been ongoing for decades to deconstruct the effects of stress on humans and to discover compounds that will reduce its negative effects. Ashwagandha is widely used in Ayurvedic and Western herbal formulas as an adaptogen** - a substance that can help our bodies naturally adapt and increase resistance to physical and emotional stress.
Practitioners worldwide believe that adaptogenic herbs and supplements are an important addition to any daily supplementation program.
Ashwagandha has been shown to increase stress resistance, improve memory-related performance, and protect against stress induced responses such as anxiety, and physiological imbalances, according to numerous animal studies and several human studies.
A comparative study of the anxiety-reducing and antidepressive actions of ashwagandha with that of Lorazepam (benzodiazepine) was conducted in mice. Mice treated with both ashwagandha and benzodiazepine exhibited a reduction in brain concentrations of a specific neuron-chemical normally elevated in those who experience anxiety. Ashwagandha, in the same study, exhibited strong anti depressive effects. The results of similar studies support the use of ashwagandha as an anti-stress adaptogen.
In a clinical study utilizing rats, the stress-reducing effects of extracts of ashwagandha were compared with those of Asian ginseng (Panax ginseng). Both ashwagandha and Panax ginseng reduced the number and severity of chronic stress–induced ulcers, reversed the chronic stress–induced inhibition of male sexual behavior, and inhibited the adverse effects of chronic stress on the retention of learned tasks.
Bhattacharya SK, Bhattacharya A, Sairam K, Ghosal S. Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine 2000;7:463-469.
Bhattarcharya SK, Muruganandam AV. Adaptogenic activity of Withania somnifera: an experimental study using a rat model of chronic stress. Pharmacol Biochem Behav 2003;75:547-555.
The anti-aging effects of Ashwagandha were shown in a double-blind clinical trial in which 101 healthy men aged 50–59 years received a dosage of 3 grams Ashwagandha for 1 year. Specifically, significant improvements in hemoglobin, red blood cell counts, hair melanin concentrations, and serum cholesterol concentrations were observed.
Kuttan G. Use of Withania somnifera Dunal as an adjuvant during radiation therapy. Indian J Exp Biol 1996;34:854-856.
Additional information on specific terms:
**Adaptogen (wikipedia) The word adaptogen is used by herbalists to refer to a natural herb product that increases the body's resistance to stresses such as trauma, anxiety and bodily fatigue. In the past they have been called rejuvenating herbs, qi tonics, rasayanas**, or restoratives. All adaptogens contain antioxidants, but antioxidants are not necessarily adaptogens and that is probably not their primary mode of action.
Knowledge about adaptogens dates back thousands of years to ancient India and China, but serious scientific study did not begin until the late 1940s. In 1947, Dr. Nikolai Lazarev defined an adaptogen as an agent that allows the body to counter adverse physical, chemical, or biological stressors by raising nonspecific resistance toward such stress, thus allowing the organism to “adapt” to the stressful circumstances..
In 1968, Israel I. Brekhman , PhD, and Dr. I. V. Dardymov formally gave adaptogens a functional definition, as follows:
1. An adaptogen is nontoxic to the recipient.
2. An adaptogen produces a nonspecific response in the body—an increase in the power of resistance against multiple stressors including physical, chemical, or biological agents.
3. An adaptogen has a normalizing influence on physiology, irrespective of the direction of change from physiological norms caused by the stressor.
Very simply, adaptogens are nontoxic in normal doses, produce a nonspecific defensive response to stress, and have a normalizing influence on the body. They normalize the hypothalamic-pituitary-adrenal axis (HPA axis). As defined, adaptogens constitute a new class of natural, homeostatic metabolic regulators.
It is claimed that adaptogenic herbs are unique from other substances in their ability to balance endocrine hormones and the immune system, and they help the body to maintain optimal homeostasis.  Adaptogens have a normalizing effect on the body and are capable of either toning down the activity of hyperfunctioning systems or strengthening the activity of hypofunctioning systems. However they are also functional at the level of allostasis** which is a more dynamic reaction to long term stress, lacking the fixed reference points of homeostasis. 
Robyn Klein. "Allostasis Theory and Adaptogenic Plant Remedies" 2004
Robyn Klein Masters Thesis Paper, May 2004, Montana State University, Dept Plant Sciences & Plant Pathology: Phylogenetic and phytochemical characteristics of plant species with adaptogenic properties
More data on Ashwagandha
Ashwagandha Exhibits Anti-Stress Activity in Rats
Pharmacological Comparison of Activities of Ashwagandha and Ginseng