By Kathy Sadowski, MS in Aromatherapy, RA, LMT
This article originally appeared in the NAHA Journal (Winter 2019) and it is republished here according to the NAHA Writer Guidelines 2019-20 copyright statement.
You may be wondering, “How can an aroma help reduce indigestion…wouldn’t it be more effective to ingest a botanical extraction if your gut aches?” Certainly, many studies have demonstrated that ingesting key herbs can aid in alleviating a variety of digestive complaints. But the internal use of essential oils can pose a significant health risk.
Essential oils, which can be 100 times more potent than the same plant’s herb, are considered unsafe to ingest without the advice of a trained expert, unless using a commercially formulated blend with internal usage instructions (1). With that being said, the therapeutic margin is small, and contraindications with medical conditions and medications taken must be considered.
Aromatherapy via inhalation can offer a gentle and effective alternative to help reduce digestive complaints. The pathophysiology of nausea / indigestion can be quite complex, going beyond just issues with the digestive system organs. Anxiety and mood can affect gastrointestinal tract motility. Thus, calming the nervous system with aromatherapy has shown in multiple scientific studies to be safe and effective in reducing nausea.
A variety of essential oil aromas have shown in human studies to help with indigestion. Ginger, and blends with ginger have shown in a significant number of studies to be very helpful, with extremely minimal negative side-effects. This article will review the physiology of how aroma can reduce indigestion, with studies demonstrating ginger aromatherapy can gently help with digestive complaints.
The Physiology of How Aroma can Improve Digestion
Stress can have a gut-wrenching effect! Digestive processes are controlled by the nervous system. When we are stressed, the sympathetic nervous system goes into fight-or-flight mode, and can cause digestive cramping, acidity, nausea, constipation, or diarrhea. Long term stress can contribute to diseases like digestive tract inflammation, irritable bowel syndrome, gastric reflux, and ulcers (2).
Reducing stress can help with indigestion. Getting our nervous system back into parasympathetic mode, also nicknamed “rest and digest,” improves our body’s unconscious bodily functions, including digestive activities.
Essential oil scents have shown to help reduce stress. What are some possible physiological mechanisms for this effect?
- Psychological Effect: Scent enters the nose, attaching to olfactory receptors, which send a message via the olfactory nerve, directly to the limbic system of the brain. Here, the amygdala and hippocampus process the aromatic stimuli and activate emotional memories. The limbic system then passes sensory information onto the voluntary and involuntary motor centers of the brain, affecting our rate of respiration, circulation, digestion, and hormone production, including cortisol (3,4).
- Pharmacological Effect: Essential oil molecules that enter the nose can then be introduced into the bloodstream via the nasal or lung mucosa, offering a possible pharmacological effect. Since most essential oil molecules are fat soluble, they will bind to lipophilic plasma proteins in the blood, then tend to leave the blood to be absorbed into fat and muscle tissue. Further, metabolism occurs, in which molecules are transformed to be more water soluble and leave the body through urination (3).
- Placebo Effect: In a scientific study, if a participant is receiving a treatment, and believes the treatment could result in a possible effect, the participant’s expectations can influence a response (3).
Human Studies on Ginger Aroma for Nausea
Ginger essential oil aroma may have both a psychological and pharmacological effect to aid in digestive malfunctions. Below are brief summaries of several human studies where the scent demonstrated a reduction in nausea.
- In a placebo-controlled study with 60 abdominal surgery patients, half received ginger aromatherapy right after surgery and showed significantly less vomiting and nausea compared to the group that did not receive aromatherapy (5).
- In a randomized and controlled study with 120 patients, those who were administered aroma of ginger applied to the collar had lower post-operative nausea (6).
- In a double-blind study involving 322 post-operative patients, ginger and peppermint aromatherapy significantly reduced nausea and vomiting (7).
- In a randomized controlled study with 90 pregnant women, the aroma of lemon and the aroma of ginger each helped reduce nausea (8).
- In 73 patients with post-operative nausea, a blend on the neck of Zingiber officinale (ginger), Elletaria cardamomum (cardamom) andArtemisia dracunculus (tarragon) essential oils in equal parts had positive results in 75% of the patients (9).
- In a randomized trial of 301 patients with post-operative nausea, ginger aromatherapy was effective in reducing symptoms (10).
- In a randomized placebo-controlled study, 184 patients were divided into four groups: lavender aromatherapy, rose aromatherapy, ginger aromatherapy, or no scent. The ginger and lavender groups showed the greatest reduction in post-operative nausea, and the rose group was slightly better than the water group (11).
- A blend of lavender, ginger, peppermint, and spearmint essential oils placed in a portable inhaler was effective in reducing nausea in 121 post-operative patients (12).
In summary, ginger aroma can be an effective and gentle way to help reduce nausea. Upon entering the nose, it may have both a phycological and/or a pharmacological effect. Multiple human studies have demonstrated this therapeutic action.
Additional essential oil aromas have also shown significant potential, including peppermint, lemon, and lavender. As a result, I would recommend this aromatherapy recipe to help with indigestion:
Indigestion Aromatherapy Recipe
- ½ tsp of ginger essential oil (Zingiber officinale)
- ½ tsp of peppermint essential oil (Menthol piperita)
- ½ tsp of lemon essential oil (Citrus limonum)
- ½ tsp of lavender essential oil (Lavendula angustifolia)
- 1 – half ounce amber glass bottle
Mix equal parts of each essential oil and safely store in a small amber bottle, labeling the date and ingredients.
- Add a few drops to a cool mist diffuser (at a rate of 1 drop per ounce of water) and enjoy for 30 minutes. Avoid diffusing in close proximity to young children and pets. Utilize diffusers in well ventilated rooms. Maybe contraindicated with certain medical conditions; consult your Doctor if you have questions.
- Or, mix the blend with a carrier oil such as jojoba or sweet almond at a rate of 10 drops per ounce of carrier oil, and then massage onto the neck. Avoid applying on young children. Not for pets. Maybe contraindicated with certain medical conditions; consult your Doctor if you have questions. Discontinue use if any irritation occurs.
- (2020). General Safety Precautions. Retrieved on 1/16/2020. Retrieved from: https://naha.org/explore-aromatherapy/safety
- Iliades, C. M.D. (10/16/18). How Stress Affects Digestion. Retrieved on 1/16/2020. Retrieved from: https://www.everydayhealth.com/wellness/united-states-of-stress/how-stress-affects-digestion/
- Peace-Rhind, J. (2012). Essential Oils. A Handbook for Aromatherapy Practice. 2nd Singing Dragon.
- Buckle, J. (2003). Clinical Aromatherapy. Essential Oils in Practice. Second Edition. Churchill Livingstone.
- Lee, Y. R., & Shin, H. S. (2017). Effectiveness of ginger essential oil on postoperative nausea and vomiting in abdominal surgery patients. The Journal of Alternative and Complementary Medicine, 23(3), 196-200.
- Adib-Hajbaghery, M., & Hosseini, F. S. (2015). Investigating the effects of inhaling ginger essence on post-nephrectomy nausea and vomiting. Complementary therapies in medicine, 23(6), 827-831.
- Fearrington, M. A., Qualls, B. W., & Carey, M. G. (2019). Essential Oils to Reduce Postoperative Nausea and Vomiting. Journal of PeriAnesthesia Nursing.
- Kustriyanti, D., & Putri, A. A. (2019). The Effect of Ginger and Lemon Aromatherapy on Nausea and Vomiting among Pregnant Women. Jurnal Keperawatan Soedirman, 14(1), 15-22.
- De Pradier, E. (2006). A trial of a mixture of three essential oils in the treatment of postoperative nausea and vomiting. International Journal of Aromatherapy, 16(1), 15-20.
- Hunt, R., Dienemann, J., Norton, H. J., Hartley, W., Hudgens, A., Stern, T., & Divine, G. (2013). Aromatherapy as treatment for postoperative nausea: a randomized trial. Anesthesia & Analgesia, 117(3), 597-604.
- Karaman, S., Karaman, T., Tapar, H., Dogru, S., & Suren, M. (2019). A randomized placebo-controlled study of aromatherapy for the treatment of postoperative nausea and vomiting. Complementary therapies in medicine, 42, 417-421.
- Hodge, N. S., McCarthy, M. S., & Pierce, R. M. (2014). A prospective randomized study of the effectiveness of aromatherapy for relief of postoperative nausea and vomiting. Journal of PeriAnesthesia Nursing, 29(1), 5-11.