Effects of Acute Ashwagandha Ingestion on Cognitive Function

Dante Xing; Choongsung Yoo; Drew Gonzalez; Victoria Jenkins; Kay Nottingham; Broderick Dickerson; Megan Leonard; Joungbo Ko; Mark Faries; Wesley Kephart; Martin Purpura; Ralf Jäger; Ryan Sowinski; Christopher J Rasmussen; Richard B Kreider

doi:10.3390/ijerph191911852

Effects of Acute Ashwagandha Ingestion on Cognitive Function

Int J Environ Res Public Health. 2022 Sep 20;19(19):11852. doi: 10.3390/ijerph191911852.

Authors

Affiliations

¹ Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843, USA.
² Texas A&M AgriLife Extension, Texas A&M University, College Station, TX 77843, USA.
³ Department of Kinesiology, University of Wisconsin, Whitewater, WI 53190, USA.
⁴ Increnovo LLC, Milwaukee, WI 53202, USA.

Abstract

Background: Ashwagandha (Withania somnifera) has been reported to decrease perceptions of stress, enhance mood, and improve cognitive function. However, it is currently unknown whether acute ashwagandha supplementation affects memory and cognitive function. This study evaluated the effects of acute ashwagandha extract ingestion on executive function.

Materials and methods: 13 healthy volunteers were administered the Berg-Wisconsin Card Sorting (BCST), Go/No-Go (GNG), Sternberg Task (STT), and Psychomotor Vigilance Task (PVTT) tests. Participants then ingested in a double-blind, placebo-controlled, and crossover manner 400 mg of a placebo (PLA) or ashwagandha (ASH) extract (NooGandha^®, Specnova Inc., Boca Raton, FL, USA). Participants then performed cognitive function tests every hour for 6 h. After a 4-day washout period, volunteers repeated the experiment while receiving the remaining supplement. Data were analyzed by repeated measures General Linear Model multivariate and univariate statistics with body weight as a covariate.

Results: Acute ASH supplementation increased STT-determined working memory as demonstrated by an improvement in 6 letter length, Present Reaction Time at 3 and 6 h. PVTT analysis revealed that ASH sustained attention by helping maintain reaction times, preventing mental fatigue, and remaining vigilant. Conversely, reaction times (at task 20, hour 6; overall, hour 3) increased with PLA. In the BCST, there was evidence that ASH increased the ability to recognize and 'shift' to a new rule compared with baseline. However, this was not seen when evaluating changes from baseline, suggesting that differences in baseline values influence results. In the GNG test, ASH ingestion promoted faster response times to respond correctly than PLA, indicating less metal fatigue. However, ASH did not affect accuracy compared to PLA, as both treatments decreased the percentage of correct answers.

Conclusions: Acute supplementation with 400 mg of ashwagandha improved selected measures of executive function, helped sustain attention, and increased short-term/working memory.

Keywords: attention; cognition; memory; nootropic; psychomotor; reaction time; reasoning.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cognition
Cross-Over Studies
Double-Blind Method
Eating
Humans
Plant Extracts / pharmacology
Plant Extracts / therapeutic use
Polyesters
Withania*

Substances

Plant Extracts
Polyesters
Ashwagandha

Associated data

ISRCTN/ISRCTN16835354

Grants and funding

This study was funded as a fee-for-service project awarded to the Human Clinical Research Facility at Texas A&M University from Specnova, Inc. (Boca Raton, FL, USA). Data were collected by members of the Exercise & Sport Nutrition Lab. Specnova was not involved in any way in data collection, analysis of the data, or the writing of the manuscript.