Ashwagandha (Withania somnifera), a small, woody shrub found growing in Africa, the Mediterranean and India, has been used in ayurvedic medicine1 for more than 3,000 years. It was described by Dioscorides (78 AD) in his book Kitab-ul-Hashaish, as a “Rasayana”—a rejuvenator “that promotes a youthful state of physical and mental health and expands happiness.”2 Ashwagandha has also been referred to as a “royal herb” due to is rejuvenative effects, acting on various systems of the body including neurological, immune, energy production, endocrine and reproductive.3 These broad-ranging effects are a function of ashwagandha’s adaptogenic properties, which help the body to adapt by normalizing physiological processes in times of increased stress.4
Different Ashwagandha Extracts
In the literature, steroidal lactones known as withanolides have been discussed as important active compounds in ashwagandha, although other compounds are also present including alkaloids (isopelletierine, anaferine, etc.) and saponins.5 Commercially, there are various ashwagandha extracts providing varying amounts of these compounds. Some of these extracts have interesting research to support their use for stress, sleep enhancement, testosterone production, athletic performance and sexual function. Recently, I was made aware of a new ashwagandha extract whose research was specific for cognitive function (NooGandha by Specnova, distributed in the U.S. by Zehn Naturals). This new extract focuses in on specific compounds with nootropic bioactivity, with less of the compounds that are highly sedative—while still retaining the stress support benefits anti-cortisol compounds.
Cognition Enhancing Ashwagandha Study 1
A double-blind, placebo-controlled, crossover study6 at Texas A&M University was conducted to examine the effect of supplementation with ashwagandha extract on executive function (i.e. mental processes that enable us to plan, focus attention, remember instructions and juggle multiple task successfully). Thirteen healthy male and female subjects (24±5 years) were randomly assigned to consume 400 mg of an ashwagandha extract (NooGandha) or placebo. Subjects completed four cognitive function tests including go no-go test (a pass/fail test), psychomotor vigilance task test (a sustained-attention, reaction-timed tasks), the Berg-Washington card sorting task (cognitive reasoning test), and the Sternberg task test (working memory tasks), and then ingested a capsule of ashwagandha extract or placebo with 8 oz. of water. Participants repeated cognitive function tests 1, 2, 3, 4, 5 and 6 hours after ingestion of the supplement. After seven days the participants then repeated the experiment, alternating to which ever treatment that they previously didn’t get. The results were that supplementation with 400 mg ashwagandha extract significantly increased short-term/working memory. Ashwagandha also resulted in sustained attention (maintained reaction times, prevention of mental fatigue), measuring a person’s ability to remain heedfully vigilant. In contrast, placebo showed significantly reduced reactions times. In addition, ashwagandha supplementation resulted in faster response times to correctly respond compared to placebo (shows less mental fatigue). In conclusion, supplementation with 400 mg ashwagandha extract resulted in sustained attention and increased short-term/working memory. This was the first time a single dose of ashwagandha has shown to have acute cognitive performance benefits.
Cognition Enhancing Ashwagandha Study 2
This randomized, double-blind, placebo-controlled study7 performed at Jacksonville University examined the effects of supplementation with ashwagandha extract for improving cognitive abilities, cortisol levels and self-reported mood, stress, food cravings and anxiety with adults with perceived stress. Healthy adults (n = 43 women and n = 17 men; age = 34.41 years) with perceived stress were randomized to the following groups: Ashwagandha (400 mg/day), ashwagandha (225 mg/d), and placebo for 30 days. The following outcomes were assessed at day 0, day 15 and day 30: saliva cortisol levels, cognitive performance (i.e., CNS Vital Signs), and the self-reported measures of trait anxiety inventory. Results were as follows:
• Cognitive Flexibility – Compared to placebo, cognitive flexibility improved significantly from day 0 to day 15 for both the ashwagandha 225 mg/d and 400 mg/d groups; and for the 225 mg/d group from day 0 to day 30.
• Visual Memory – Compared to placebo, visual memory improved significantly from day 0 to day 15 to day 30 for the ashwagandha 400 mg/d and 225 mg/d group.
• Reaction Time – Compared to placebo, reaction time improved significantly from day 0 to day 15 for the ashwagandha 400 mg/d and 225 mg/d groups.
• Psychomotor Speed – Compared to placebo, psychomotor speed improved from day 0 to day 15 for the ashwagandha 225 mg/d and 400 mg/d groups, and from day 0 to day 30 for the 225 mg group.
• Executive Functioning – Compared to placebo, executive functioning improved significantly from day 0 to day 30 for the ashwagandha 225 mg/d.
• Cortisol levels – For cortisol levels, at day 15 and day 30 the ashwagandha 225 mg/d group had significant reductions compared to baseline. A time effect was evidenced for the ashwagandha 225 mg/d group with larger effects found at 30 day compared to day 15. The ashwagandha 400 mg/d group had a reduction in cortisol levels from baseline to day 15 to day 30, although not with the same degree of significance. By comparison, the placebo group had a slight increase in cortisol levels from baseline to day 15 and 30.
The researchers concluded that supplementation with ashwagandha extract may improve the physiological, cognitive and psychological effects of stress.
Ashwagandha has been used in ayurvedic medicine for more than 3,000 years, and has rejuvenative effects, acting on various systems of the body. Although various ashwagandha extracts have been shown to be useful for stress, sleep enhancement, testosterone production, athletic performance and sexual function, the novel ashwagandha extract known as NooGandha (by Specnova, distributed in the U.S. by Zehn Naturals) is specific for cognitive function. Two human clinical trials have demonstrated that 225 mg/d and 400 mg/d of NooGandha significantly improved short-term/working memory, sustained attention, cognitive flexibility, visual memory, reaction time, psychomotor speed, executive functioning and decreased cortisol levels.
1 Anonymous. Monograph. Withania somnifera. Altern Med Rev 2004;9:211-4.
2 Uddin, Q., Samiulla, L., Singh, V.K. and Jamil, S.S. Phytochemical and Pharmacological Profile of Withania somnifera Dunal: A Review. JAPS 2012;2:170-5.
3 Singh, N., Bhalla, M., de Jager, P. and Gilca, M. An Overview on Ashwagandha: A Rasayana (Rejuvenator) of Ayurveda. Afr J Tradit Complement Altern Med 2011;8:208-13.
4 Provino R. The role of adaptogens in stress management. Aust J Med Herbal. 2010;22:41-9.
5 Uddin, Q., Samiulla, L., Singh, V.K. and Jamil, S.S. Phytochemical and Pharmacological Profile of Withania somnifera Dunal: A Review. JAPS 2012;2:170-5.
6 Xing D, Yoo C, Rasmussen CJ, et al. Acute ashwagandha supplementation improves cognitive performance. JISSN. 2020 17:67.
7 Remenapp A, Coyle K, Orange T, et al. Effectiveness of Ashwaganda (Withania somnifera) Supplementation on Adult’s Cognition and Mood. Submitted to Journal of Ayurveda and Integrative Medicine as a short communication; 2021.
Gene Bruno, MS, MHS, the dean of academics for Huntington College of Health Sciences, is a nutritionist, herbalist, writer and educator. For more than 30 years he has educated and trained natural product retailers and health care professionals, has researched and formulated natural products for dozens of dietary supplement companies, and has written articles on nutrition, herbal medicine, nutraceuticals and integrative health issues for trade, consumer magazines and peer-reviewed publications. He can be reached at firstname.lastname@example.org.