A Randomized Trial of Olfactory Stimulation Using Black Pepper Oil in Older People with Swallowing Dysfunction

Authors

  • Takae Ebihara MD, PhD,

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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  • Satoru Ebihara MD, PhD,

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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  • Masahiro Maruyama MD,

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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  • Mitsuru Kobayashi BS,

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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  • Azusa Itou BS,

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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  • Hiroyuki Arai MD, PhD,

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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  • Hidetada Sasaki MD, PhD

    1. From the Departments of *Geriatric and Respiratory MedicineGeriatric and Complementary Medicine, Tohoku University School of Medicine, Sendai, JapanHikari Pharmacy§Kansei Welfare Research Center, Tohoku Welfare University, Sendai, Japan.
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Address correspondence to Takae Ebihara, MD, PhD, Department of Geriatric and Respiratory Medicine, Tohoku University School of Medicine, Sendai, Japan 980–8574. E-mail: takae_Montreal@hotmail.com

Abstract

OBJECTIVES: To determine the effect of olfactory stimulation with volatile black pepper oil (BPO) on risk factors for pneumonia.

DESIGN: A 1-month randomized, controlled study.

SETTING: Nursing homes in Japan that serve as long-term care facilities for older residents who are physically handicapped, mainly because of cerebrovascular disease.

PARTICIPANTS: One hundred five poststroke residents.

MEASUREMENTS: Latency of the swallowing reflex (LTSR), the number of swallowing movements, serum substance P (SP), and regional cerebral blood flow (rCBF).

RESULTS: Nasal inhalation of BPO for 1 minute shortened LTSR, compared with that of lavender oil and distilled water (P<.03). Compared with the period before the study, the 1-month intervention using BPO improved LTSR with an increase of serum SP (P<.01). The number of swallowing movements for 1 minute during the nasal inhalation of BPO increased (P<.001). Multiple comparisons showed a poststudy increase in rCBF within the insular cortex (P<.001). Compared with the prestudy rCBF, BPO intervention increased rCBF in the right orbitofrontal and left insular cortex (P<.001).

CONCLUSION: Inhalation of BPO, which can activate the insular or orbitofrontal cortex, resulting in improvement of the reflexive swallowing movement, might benefit older poststroke patients with dysphagia regardless of their level of consciousness or physical and mental status.

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