With their warm, sweet taste and unique aroma, cloves are used in cuisines worldwide. This versatile spice is ideal for marinades, sauces, meat dishes and desserts. The oil extracted from cloves boasts high antioxidant levels, but it also comes with its share of side effects.
Cloves and Your Health
This spice comes from Syzygium aromaticum, a tree native to Indonesia. It's commonly added to red meats, mulled wine, fruit pies, cakes, pumpkin recipes, pickles and other recipes. The dried flower buds, stems and leaves exhibit therapeutic effects. Manufacturers add cloves to cigarettes, perfumes, personal care products and even toothpaste.
For example, a review published in Oncology Research in August 2014 suggests that clove extract may suppress tumor growth and induce cancer cell death. Until recently, researchers knew that it exhibits antiseptic, antiviral and antimicrobial properties. These effects are attributed to eugenol, kaempferol, stigmasterol and other bioactive compounds. Its anti-cancer properties, though, require further investigation.
Another review, which was featured in Medicina Oral Patologia Oral y Cirugia Bucal in June 2015, assessed the efficacy of different treatment methods for dry socket. Also known as alveolar osteitis, this condition may occur after dental extractions, leaving the bone exposed. If left unaddressed, it can lead to severe pain and infection.
Researchers have found that zinc oxide and eugenol, an active compound in clove, may relieve dry socket pain and accelerate healing. These ingredients have antiseptic and anesthetic properties, reducing the perception of pain. Furthermore, eugenol may help reduce inflammation and kill off oral bacteria. Considering these facts, it's not surprising that many people use clove essential oil for toothache and other dental problems.
How Does Clove Oil Work?
Clove oil has been prized for its healing power for centuries. Eugenol, one of its key compounds, is used in toothpaste, mouthwash and medications prescribed by dentists worldwide. Unfortunately, there isn't enough evidence to support its therapeutic effects. The FDA has actually downgraded its effectiveness rating for toothache, according to the Mayo Clinic.
Most studies involving clove oil have been conducted on animals or in vitro (a controlled lab environment). Therefore, they may not be accurate or conclusive. The side effects of clove oil, on the other hand, are well-documented.
A September 2016 research paper published in the journal Molecules suggests that clove oil may protect against Staphylococcus aureus, depending on its concentration. Its antibacterial effects were attributed to eugenol, which accounts for more than 75 percent of its content.
S. aureus, or golden staph, is a bacterium that may lead to infection, skin abscesses, cell death and life-threatening disorders. It's estimated that about one-third of the world's population carries this microbe, as reported in a January 2019 review featured in Frontiers in Immunology. Individuals with a weak immune system are at greater risk. Eugenol may destroy the cell walls and membranes of this bacterium and suppress its growth, according to the Molecules review.
Clove oil may also help treat Candida infections, as noted in a June 2017 article posted in the International Journal of Molecular Sciences. It alters the protein and enzymatic profiles of yeasts, reducing their ability to harm the host.
Take these findings with a grain of salt. The studies were conducted in vitro, so more research is needed to confirm the results.
Clove Oil Is Allergenic
Like most natural remedies and medications, clove oil may cause adverse effects. The Mayo Clinic warns about the dangers of injecting it into the veins or applying it on the gums. Clove oil injections, for example, may affect the lungs and cause respiratory problems. Those who apply it on their gums may experience damage to their oral tissues.
Some individuals are allergic to eugenol, the primary compound in clove oil. According to a September 2013 case report, this chemical may cause allergic contact dermatitis and hypersensitivity. The article, published in the BMJ Case Reports, states that eugenol is considered safe by the FDA and other health organizations. However, there is still a risk of anaphylaxis and hypersensitivity reactions.
Anaphylaxis, a severe allergic reaction, can be fatal. Its symptoms include hives, nausea and vomiting, fainting, stomach pain, difficulty breathing and low blood pressure.
The BMJ Case Reports article describes the case of an 8-year-old boy treated with zinc oxide eugenol after a pulpectomy, or nerve treatment. About one minute later, he showed signs of anxiety and experienced skin reactions, such as erythema and itchiness. These symptoms subsided two hours after he received treatment and had the zinc oxide eugenol dressing removed.
As the researchers point out, eugenol is allergenic and may cause severe symptoms, such as tissue necrosis. These side effects are rare, though. To stay safe, ask your dentist to conduct an allergy test. If you plan to take clove essential oil for toothache or other health issues, make sure you're not allergic to it.
Other Potential Side Effects
Blistering and swelling of the mouth, skin irritation and gum damage are all potential side effects of clove oil. This natural remedy can also interact with medications that prevent blood clotting, according to the Electronic Medicines Compendium (eMC). Additionally, it may not be safe during pregnancy and breastfeeding. As a rule of thumb, avoid using it for long periods of time and apply it with caution in the mouth.
If you have tooth pain, you may apply a small amount of clove oil on the affected area. Just make sure you avoid the surrounding gums. Do not use this product for teething pain in small children.
Beware that high doses may cause severe reactions, from painful urination and bloody urine to burns in the mouth, seizures and rapid heartbeat, as reported by the U.S. National Library of Medicine. In the worst-case scenario, overdoses can lead to liver failure and even coma. Other adverse effects may include shortness of breath, rapid heartbeat and coughing up blood.
Don't take unnecessary risks. Most medications carry potential side effects — and clove oil is no exception. Just because it's natural doesn't mean it's safe. Consult a medical professional before using it and increase the dose gradually to see how your body reacts.
- Royal Botanic Gardens, Kew: "Syzygium aromaticum"
- Mayo Clinic: "Clove"
- Oncology Research: "Clove Extract Inhibits Tumor Growth and Promotes Cell Cycle Arrest and Apoptosis"
- Medicina Oral Patologia Oral y Cirugia Bucal: "Efficacy of Different Methods Used for Dry Socket Management: A Systematic Review"
- Mayo Clinic: "Dry Socket"
- NCBI: "Multimodal Management of Dental Pain With Focus on Alternative Medicine: A Novel Herbal Dental Gel"
- The Marshall Protocol Knowledge Base: "Differences Between in Vitro, in Vivo, and in Silico Studies"
- Molecules: "Chemical Composition, Antibacterial Properties and Mechanism of Action of Essential Oil From Clove Buds Against Staphylococcus aureus"
- Frontiers in Immunology: "A Genome-Wide Screen Identifies Factors Involved in S. aureus-Induced Human Neutrophil Cell Death and Pathogenesis"
- MDPI: "Candida Albicans Impairments Induced by Peppermint and Clove Oils at Sub-Inhibitory Concentrations"
- BMJ Case Reports: "An Unexpected Positive Hypersensitive Reaction to Eugenol"
- ACAAI: "Anaphylaxis"
- Electronic Medicines Compendium: "Clove Oil"
- Medline Plus: "Eugenol Oil"