Kava, traditionally influenced consumption volumes, and impacts on driver fitness

Abstract

Introduction: Kava (Piper methysticum), a culturally significant Pacific Island beverage, produces soporific relaxant effects similar to Benzodiazepine. Traditional users typically consume this drink at volumes 20 times greater than pharmacologically recommended doses, with many then driving home. This study, funded by the New Zealand Health Research Council (19/002), assessed six key cognitive functions related to safe driving, following kava use. Methods: Guided by the faikava methodology, male kava consumers (n=20) attended a six-hour kava session, each drinking 3.6 litres of kava. Drinkers were compared to a control group (males; n=19). At baseline (T1) all participants completed Brain Gauge testing - a somatosensory tool that measures cognitive functioning in six-areas. Re-testing was completed at three (T2) and six hours (T3). Statistical modelling comprised Wilcoxon and Mann-Whitney U (MW), and Bayesian (BF) analysis. Results: Analysis indicated no statistically significant (p<0.05) difference to the focus, accuracy, time perception, plasticity or fatigue of the active participants when compared against control at T1, T2 or T3. Conversely, data analysis showed a significant level of impairment to the temporal order judgement (TOJ) of the active participants at T3 ([MW=0.0119; t=0.007301; BF=6.193058]) when compared with both their own and control data at T2 and T1. Conclusions: Kava at traditional consumption volumes is shown to significantly impact TOJ. TOJ is associated with Executive Function, particularly sequencing. This new understanding suggests kava, at traditionally consumed volumes, impacts upon cognitive functioning, and therefore may compromise driver safety. This presentation expands on these findings combined with a recent kava drink-driving awareness program. Sponsorship: The study is funded by the New Zealand Health Research Council (19/002).