Table 1.

Peppermint Oil (PMO) Effect on Human Esophageal Function

Reference	Population	Methods	Findings
Sigmund (1969)43	Healthy subjects (n=27)	Esophageal manometry measuring the lower esophageal sphincter (LES) and esophageal body Completed following 15 drops of PMO (presumably ~687 mg). Most subjects also had air infused into the stomach (24 of 27). Controls (n=7) were given saline alone	22/24 subjects given PMO after air infusion demonstrated “reflux”: decrease in LES pressure until equal pressure stomach and esophageal pressure 3/3 given PMO without air prior had decrease in LES pressure Mean duration before response to peppermint: 168.6 seconds ± 97.2 seconds Duration of sphincter relaxation: 27.8 ± 8.8 seconds to PMO vs. 7.9 ± 3.8s with swallowing No LES relaxation in controls (saline)
Pimentel (2001)45	Adults with diffuse esophageal spasm (n=8)	Esophageal manometry at baseline then 10 minutes after PMO 5 drops of 11% PMO (presumably ~25 mg) in 10 mL water	No effect on LES or esophageal body pressure PMO decreased simultaneous esophageal contractions in all patients (P<0.01) and increased propagated body contractions (P<0.01); decreased contraction variability Two of eight had improvement in chest pain
Mizuno (2006)44	Adult patients undergoing upper double contrast barium study (n=420)	Nonrandomized study: (n=205) given PMO: 10 mL of 1.6% solution vs. (n=215) given water Degree of spasm for esophagus blindly scored (0-3 range, indicating none to severe)	Fewer esophageal spasms seen in PMO group than in controls: 0.35 ± 0.04 vs 0.65 ± 0.04 (P<0.001)

Unless otherwise indicated data are presented as mean ± standard deviation.