Cloves, the dried flower buds of the Syzygium aromaticum tree, are a fragrant and flavorful spice used in cooking and traditional medicine for centuries. The potent aroma and flavor come primarily from the compound eugenol. While small amounts of cloves used in culinary dishes are generally safe for most people, the high concentration of eugenol in clove essential oil, supplements, or potent teas poses significant health risks for specific populations. A clear distinction must be made between culinary use and therapeutic, concentrated intake.
Individuals with Bleeding Disorders and on Blood Thinners
One of the most critical warnings regarding clove consumption is for those with bleeding disorders or who take anticoagulant (blood-thinning) or antiplatelet medications. The eugenol in cloves has properties that can slow down blood clotting. For individuals with conditions like hemophilia or those on drugs such as warfarin, aspirin, or ibuprofen, this can increase the risk of bleeding and bruising. This interaction can be severe and should not be taken lightly. It's essential to consult a healthcare provider before using any concentrated clove product if you have a history of bleeding issues or are on related medication.
People Scheduled for Surgery
Because cloves can interfere with normal blood clotting, they should be avoided for a period before any surgical procedure, including dental work. Experts recommend discontinuing the use of cloves, especially supplements or high doses, at least two weeks before a scheduled surgery to prevent complications with excessive bleeding during or after the operation.
Individuals with Diabetes and Blood Sugar Concerns
Research suggests that cloves may help lower blood sugar levels. While this sounds promising, it can be dangerous for people with diabetes, particularly those taking medication like insulin to control their blood glucose. Combining clove supplements with antidiabetic drugs could cause blood sugar levels to drop too low, leading to severe hypoglycemia, a potentially life-threatening condition. Close monitoring of blood sugar is crucial if a person with diabetes considers incorporating cloves beyond normal culinary amounts.
Pregnant and Breastfeeding Individuals
For pregnant and breastfeeding women, clove consumption should be limited to the small amounts typically found in food. There is insufficient reliable safety data regarding the effects of larger, medicinal doses of cloves or clove oil on an unborn baby or during lactation. To stay on the safe side, concentrated clove products like supplements or essential oils should be avoided entirely during these sensitive periods.
Infants and Young Children
Concentrated clove oil is extremely dangerous for infants and young children. Accidental ingestion of even small amounts can be toxic and lead to severe side effects such as seizures, liver damage, and fluid imbalances. Cases of severe liver injury and coma have been reported following the ingestion of clove oil by children. Parents and caregivers should ensure all clove products are stored out of children's reach. While small amounts of ground cloves in food for babies over 6 months may be introduced cautiously, whole cloves are a choking hazard and should be removed from food before serving.
Those with Allergies or Sensitivity to Eugenol
Eugenol, the primary compound in cloves, is a known allergen for some individuals. Exposure can cause allergic reactions ranging from contact dermatitis and skin irritation to more severe symptoms like itching or difficulty breathing. People with a known sensitivity to eugenol or other related spices should avoid clove products. This can also apply to dental treatments containing eugenol, which historically caused localized gum irritation.
Individuals with Liver Disease
As with many herbal supplements, individuals with liver disease should be cautious about consuming high doses of cloves. Clove oil, in particular, is toxic to the liver in high concentrations, potentially causing acute liver damage. It's also important to consider potential interactions with medications that are processed by the liver. The risk of hepatotoxicity from overdose is a serious concern, as documented by medical literature. For comprehensive information on the risks of eugenol overdose, resources like LiverTox on the NCBI Bookshelf provide detailed case reports.
Comparison: Culinary Cloves vs. Concentrated Clove Products
| Feature | Culinary Cloves (Whole or Ground Spice) | Concentrated Clove Oil/Supplements |
|---|---|---|
| Eugenol Concentration | Low, part of a complex matrix of compounds | Very high, up to 90% in some clove oils |
| Recommended Use | Flavoring for food, beverages, and baked goods | Medicinal or therapeutic use, often topical or in specific dental applications |
| Key Risks | Minimal for most adults when used moderately. Choking hazard for children with whole cloves. | Significant risk of toxicity, especially in overdose. Can cause seizures, liver damage, and bleeding issues. |
| Drug Interactions | Low risk for interactions at culinary doses | High potential for interaction with blood thinners and diabetes medications |
| Safety for Vulnerable Groups | Generally safe in moderation for most, with caution for pregnant women | Unsafe for children, pregnant/breastfeeding women, those with bleeding disorders, diabetes, and liver issues |
Conclusion: Prioritize Safety and Moderation
While cloves are a flavorful and antioxidant-rich spice, their safety profile changes dramatically when consumed in concentrated forms like supplements, teas, or essential oils. The compound eugenol, while beneficial in small doses, becomes a toxic substance at higher concentrations, posing significant risks. Individuals with bleeding disorders, diabetes, liver disease, or allergies to eugenol should be particularly cautious or avoid concentrated clove products altogether. Pregnant and breastfeeding women and children must also exercise extreme caution. The golden rule is always moderation and, when in doubt, consult a healthcare provider before using cloves for therapeutic purposes. Enjoy cloves as a spice, but never assume that more is better when it comes to concentrated forms.
