Olfactory Stimulation with Japanese Soy Sauce Improves Upper Limb Performance.

Yutaka Yano,Masahiro Yamaguchi,Mutsuo Taniguchi,Yoshihiro Murata,Hideto Kaba,Fumino Okutani

doi:10.1155/2019/2748721

Abstract

Background We have observed changes in body reactions during cooking, which is one of the treatment modalities used in occupational therapy. The perception of food-related odors during cooking may have behavioral effects on human activities through the activation of appetitive motivation. Objectives We investigated whether odor components contained in seasonings could facilitate the human motor system and the specificity of this effect. Methods The subjects were 72 healthy adults, randomly assigned to a water exposure group, a phenylethyl alcohol (PEA, pleasant rose-like odor) exposure group, and a Japanese soy sauce (Koikuchi Shoyu) exposure group (n = 24 each). The subjects' olfactory sense was stimulated by their sniffing of three different test tubes containing 5 ml of water, PEA, or Japanese soy sauce for 20 sec while they were seated. The modified Functional Reach Test (mFRT), which mimics a functional activity that is required in daily living and assesses a reliable measure of sitting balance, was performed prior to and immediately after the sniffing. Results Sniffing the soy sauce increased the subjects' mFRT scores. This facilitation effect was odorant-specific and was absent when the subjects were presented with water or PEA. Conclusions Cooking interventions are aimed at improving tool-handling skills such as using knives and chopsticks. The results indicate that treatment interventions using odors of seasonings would be effective for improving subjects' physical functions.

Highlights

BackgroundWe have observed changes in body reactions during cooking, which is one of the treatment modalities used in occupational therapy
After experiencing a stroke, which is a common cause of long-term disability, many patients with central nervous system (CNS) disorders have difficulty with instrumental activities of daily living (IADLs)
We first selected Japanese soy sauce (Koikuchi Shoyu) as a powerful appetitive cue used for olfactory stimulation, because this is a signature seasoning in Japanese food culture and is obtained in daily life

Summary

Background

We have observed changes in body reactions during cooking, which is one of the treatment modalities used in occupational therapy. We investigated whether odor components contained in seasonings could facilitate the human motor system and the specificity of this effect. The subjects were 72 healthy adults, randomly assigned to a water exposure group, a phenylethyl alcohol (PEA, pleasant rose-like odor) exposure group, and a Japanese soy sauce (Koikuchi Shoyu) exposure group (n = 24 each). The subjects’ olfactory sense was stimulated by their sniffing of three different test tubes containing 5 ml of water, PEA, or Japanese soy sauce for 20 sec while they were seated. Sniffing the soy sauce increased the subjects’ mFRT scores. This facilitation effect was odorant-specific and was absent when the subjects were presented with water or PEA. The results indicate that treatment interventions using odors of seasonings would be effective for improving subjects’ physical functions

Introduction

Materials and Methods

Results and Discussion

Conclusions