Written by Chrystal Moulton, Staff Writer. Ashwagandha reduced reaction time by 7%.

Ashwagandha is a very popular herb used in Ayurvedic practice, which is a form of naturopathic medicine originating in India. Also know as “Indian ginseng”, ashwagandha is prized for its’ anti-inflammatory, anti-tumor, and immune boosting properties and is commonly prescribed for stress and fatigue.(1,2) Ashwagandha also contains antioxidants shown to improve brain and nervous system functioning as well.(2,3) In the current study, researchers wanted to test the beneficial effects of ashwagandha on brain and motor functioning. They investigated whether improvements in brain function was linked to better reaction times in healthy adults.(3)

Twenty-six healthy males aged 20-35 years were recruited to take part in this prospective double-blind placebo controlled study. Participants were randomly assigned to take 500 mg of standardized ashwagandha extract (2 capsules) twice daily or a placebo for 14 days. A washout period of 14 days immediately followed. After the washout period, individuals who were initially assigned to take the extract were switched to the placebo, while individuals who originally took the placebo were given the extract.

Before and after taking the assigned capsules for 14 days, volunteers underwent reaction time tests for 1 hour.

Table 1. Reaction times for various cognitive tests

  Simple Reaction Test (seconds) Choice Discrimination Test (seconds) Digit Symbol Substitution Test (seconds) Digit Vigilance Task (milli-seconds) Card Sorting Test (seconds)
Pre-treatment
Placebo 313 ± 45.46 476 ± 33.61 1690 ± 278 1371 ± 79.49 98 ± 17.11
Ashwagandha 306 ± 38.84 471 ± 34.40 1695 ± 262 1360 ± 57.02 95.90 ± 19.13
Post-treatment
Placebo 316 ± 26.35 477 ± 29.90 1739 ± 312 1398 ± 82.18 97.65 ± 19.93
Ashwagandha 287 ± 43.34 β‡ 455 ± 50.52 α† 1557 ± 233 γ† 1317 ± 87.98 β‡ 84.30 ± 12.66 α†

 

*Pre-treatment means tests done before taking designated capsule; post-treatment means tests done after taking assigned capsule for 14 days. Average reaction time for each test is displayed. The symbols indicate: (α) p<0.05, (β) p<0.01, (γ) p<0.001 compared to pretreatment with ashwagandha. The symbols indicate: (†) p< 0.05 and (‡) p< 0.01 compared to post-treatment with placebo.

Results showed that ashwagandha significantly decreased the reaction time in multiple cognitive tests after 14 days of supplementation. In one test, participants average reaction time decreased by 7%. Researchers concluded that ashwagandha could be a promising natural product in the area of brain functioning and research. Due to the small sample size and short duration of the current trial, authors suggested for future research to test long-term in multiple areas the effects of ashwagandha on individuals with brain diseases.

Source: Pingali U, Pilli R, Fatima N. Effect of standardized aqueous extract of Withania somniferaon tests of cognitive and psychomotor performance in healthy human participants. Phcog Res 2014;6:12-8

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Posted May 22, 2014.

Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.

References:

  1. Singh N et al. An overview on ashwagandha: a Rasayana (rejuvenator) of Ayurveda. Afr J Tradit Complement Altern Med. 2011;8(5 Suppl):208-13.
  2. Ven Murthy MR, et al. Scientific basis for the use of Indian ayurvedic medicinal plants in the treatment of neurodegenerative disorders: ashwagandha. Cent Nerv Syst Agents Med Chem. 2010 Sep 1;10(3):238-46.
  3. Pingali U, Pilli R, Fatima N. Effect of standardized aqueous extract of Withania somnifera on tests of cognitive and psychomotor performance in healthy human participants. Pharmacognosy Res. 2014 Jan;6(1):12-8.