Sharing research on Lemon to explore its helpful properties.  The two studies shared on (Citrus x limon) are an great of its versatility.  The first study looks as the results achieved when inhaled during pregnancy to combat nausea and vomiting, while the second takes a look at its potential affect on the Autonomic Nervous System.

You can read more about what I have to say about Lemon in my article on Lemon and the blog post Lemon Reviewed.

Because the first study focuses on Nausea and Vomiting in pregnancy, you might also find the article on Nausea, Vomiting and Travel Sickness helpful.

Lemon is also the essential oil highlighted in the Bev Hawkins Membership Club December 2020 Package.

Research on Lemon Study 1 

Iran Red Crescent Med J. 2014 Mar; 16(3): e14360.
Published online 2014 Mar 5.  doi:10.5812/ircmj.14360

The Effect of Lemon Inhalation Aromatherapy on Nausea and Vomiting of Pregnancy: A Double-Blinded, Randomized, Controlled Clinical Trial

Parisa Yavari kia, Farzaneh Safajou, Mahnaz Shahnazi, and Hossein Nazemiyeh

Abstract

Background

Nausea and vomiting of pregnancy are amongst the most common complaints that effects on both the physical and mental conditions of the pregnant women.  Today more women use herbal medications during pregnancy so this study is designed to investigate the effect inhaling lemon essential oil has on nausea and vomiting. 

Objectives

The aim of this study was to determine the effect of lemon inhalation aromatherapy on nausea and vomiting during pregnancy.

Materials and Methods

In this randomized clinical trial 100 pregnant women who experience nausea and vomiting were randomly divided into two groups.  The intervention and control groups were based on four- and six-random block sampling method. Lemon essential oil and placebo were given to the intervention and control groups, respectively, to inhale it as soon as they felt nausea. The nausea, vomiting, and retch intensity were investigated 24 hours before and during the four days of treatment by means of PUQE-24 (24-hour Pregnancy Unique Quantification of Emesis).

Results

There was a statistically significant difference between the two groups in the mean scores of nausea and vomiting on the second and fourth days (P = 0.017 and P = 0.039, respectively). The means of nausea and vomiting intensity in the second and fourth days in the intervention group were significantly lower than the control group. In addition, in intragroup comparison with ANOVA with repeated measures, the nausea and vomiting mean in the five intervals, showed a statistically significant difference in each group (P < 0.001 and P = 0.049, respectively).

Conclusions:

Lemon scent can be effective in reducing nausea and vomiting of pregnancy.

Research on Lemon Study 2

Journal of Korean Academy of Nursing
Volume 40(5), October 2020, Pages 705 – 713
Published online October 31, 2010. https://doi.org/10.4040/jkan.2010.40.5.705
Copyright 2010 Korean Society of Nursing Science

Effects of Aromatherapy on Changes in the Autonomic Nervous System, Aortic Pulse Wave Velocity and Aortic Augmentation Index in Patients with Essential Hypertension.

Cha, Jung-Hee; Lee, Sun-Hee; Yoo, Yang-Sook

Abstract

Purpose

To investigate the effectiveness of aromatherapy on blood pressure, heart rate variability, aortic pulse wave velocity and the aortic augmentation index of essential hypertensive patients.

Methods

Using a coin toss, 22 participants were assigned to the experimental group and 20 to the control. The experimental group was given a blend of oils of lemon (Citrus limonum), lavender (Lavandula angustifolia), and ylang ylang (Cananga odorata).  Blended in the ratio of 2:2:1, respectively. The control group was given an artificial lemon fragrance of Limonene (35 cc) and Citral (15 cc) mixture. The experiment, inhalation, was conducted for 3 weeks (2 min per inhalation, 2 times per day) to both groups.

Results

There was a noticeable difference in systolic blood pressure between the groups (p=.001). However the difference in diastolic blood pressure between the two groups was not significant. There was a notable difference in sympathetic nerve system activity of heart rate variability (p=.047). However, the differences in aortic pulse wave velocity or the aortic augmentation index were not significant.

Conclusion

Aromatherapy is effective in lowering systolic blood pressure and sympathetic nerve system activity.