Clove: Overview, Benefits, Uses, Side Effects

Clove is a dried flower bud that grows on an evergreen tree native to Indonesia and certain parts of Asia. Its scientific name is Syzygium aromaticum. Clove is an essential condiment used in Indian cuisine. The flower bud is used as a ground powder or in its natural form. Clove is a spice used in various dishes like curries, tea, desserts, cookies, and cakes. It has been a vital ingredient in the traditional medicine system for centuries, particularly in Ayurveda and Traditional Chinese Medicine (TCM). It is not only used as a kitchen spice but also in mouthwash and herbal oils.

Health Benefits of Cloves

Cloves are a versatile spice that adds flavour while also traditionally being recognized for their health benefits. They are high in antioxidants, and preliminary research suggests they may help regulate blood sugar, kill bacteria, and more.

Here are some health benefits of eating cloves:

1. Antimicrobial Effect

Clove oil has been demonstrated to have an antimicrobial effect on various strains and categories of microbes, including bacteria and fungi [1], [2]. Research has shown the effectiveness of clove oil against certain Staphylococcus species in laboratory settings. A 0.05% solution of eugenol has been historically noted in research to potentially destroy Bacillus tuberculosis in vitro [2].

Essential oil component eugenol, when dispersed in a concentrated sugar solution, demonstrated an antimicrobial effect against various bacteria, such as Pseudomonas aeruginosa, Clostridium perfringens, E.coli, and the yeast Candida albicans [2]. This activity supports its traditional use for purification and preservation.

2. Anti-inflammatory and Wound Healing Potential

Eugenol, the primary component of clove oil, was observed in a preclinical study to be as effective as diclofenac gel in an animal model [3]. It is instrumental in healing wounds and reducing inflammation by approximately 20–30% in that specific study [3].

According to a study, wounds in rats treated with clove essential oil were found to heal faster [3].

Clove oil contains flavonoids, which may have anti-inflammatory properties [4]. It is commonly used in aromatherapy, where it is traditionally believed to help alleviate symptoms associated with conditions like arthritis and rheumatism. It is important to note that most evidence supporting these effects is preliminary, and more comprehensive clinical research in humans is needed to confirm its effectiveness for these therapeutic uses.

3. Antioxidant Activity

Clove oil has been shown to contain flavonoids and phenolic compounds that can help destroy free radicals [2], [5]. These compounds contribute to its high Oxygen Radical Absorbance Capacity (ORAC) value. The acute administration of an ethanolic extract of clove has been shown to improve the processes of learning and memory recall in mice, which supports the antioxidative effect of the eugenol component [2].

4. Potential Anti-diabetic Activity

Some studies have suggested that clove extracts may help in regulating blood sugar levels, with research showing potential effects in diabetic mice [6], [7]. Compounds like nigericin (NGC) found in clove extracts have been explored for their potential to reduce insulin resistance in animal models [8]. While promising, it must be emphasised that further research in humans is needed to confirm these findings and establish safety and efficacy for diabetes management [6].

5. Support for Liver Health (Hepatoprotective Activity)

The ethanol extract of clove has been significantly beneficial for liver cells in animal models [2]. It has demonstrated hepatoprotective activity against paracetamol-induced liver injury in female rats [2]. The compound in the clove extract acts on free radicals that cause damage to the liver cells, suggesting a protective mechanism via its antioxidant properties [2].

6. Anticancer Research

Clove oil components, like eugenol, alpha-humulene, and beta-caryophyllene, have exhibited antitumor activity in laboratory and preclinical studies [2]. According to some studies, clove oil extracts have been investigated for their potential benefit in reducing the harmful effects of chemotherapy, such as nausea, vomiting, decreased appetite, and weight loss [9]. Crucially, cloves should not be used as a substitute for standard cancer treatment, and any complementary use should be discussed with an oncologist.

7. Analgesic Properties (Pain Relief)

Clove Essential Oil (CEO) aids in treating headaches, joint pain, toothaches, and oral hygiene issues [2]. CEO has been used since ancient times as it is considered generally safe for topical application, a medically effective, and cheap remedy to get rid of pain [2]. Its primary compound, eugenol, is recognized for its mild anesthetic properties.

8. Oral Health Benefits

According to various research, Syzygium aromaticum Clove oil (or Laung in Ayurvedic tradition) helps manage toothaches, cavities, and pyorrhea [10]. Clove oil aids in the decrease of plaque deposition on oral hard tissues [11]. The antibacterial activity of clove oil implies that it could be used as a supplement to periodontal therapy [11]. Clove consumption may also help reduce the growth of Candida albicans in the gastrointestinal tract, including the mouth cavity [2].

How to Use Clove

Clove is an all-around spice. It has numerous medicinal and therapeutic uses based on traditional knowledge and initial research. However, you can use it in your daily routine in various ways:

• Add to spice your food: Cloves have a beautiful aroma and a strong taste that makes our dishes very flavourful. You can add it to your curry or pulao rice, or biryani. Or crush it and add it to your dessert.
• With hot beverages: You can add powdered clove to your tea or to warm water as a digestive aid.
• Use as an insect repellent: You can add a few drops of clove oil to the water and spray it in the house. It can keep mosquitoes and bugs away [2].
• To treat a toothache: Warm clove water or a small amount of clove oil diluted in a carrier oil can be used as a topical application for temporary relief from uncomfortable toothaches.

Side Effects of Clove

Cloves are widely used for their medicinal and culinary benefits, but as with any potent substance, excessive consumption or inappropriate use can lead to some side effects. It is essential to use clove and clove oil responsibly and in moderation. Below are the potential side effects of cloves:

1. Increased Bleeding Risk

• According to research, Clove is one herbal substance that may potentially raise bleeding risk or amplify the effects of warfarin medication [12].
• Eugenol, present in the clove, increases the risk of bleeding by potentially inhibiting platelet aggregation. Thus, clove exhibits an antiplatelet effect that can be a concern when combined with blood thinners [12].

2. May Cause Hypoglycemia

A study suggests that cloves have shown a hypoglycemic effect in type 2 diabetes patients, i.e., they aid in lowering blood sugar when consumed in specific extract forms [6].

However, if a person is already on diabetes medication, it may cause an extreme lowering of blood sugar levels (hypoglycemia) [8]. Therefore, it is strongly advised that if you are on diabetes medications, please consult your endocrinologist or a qualified physician before adding cloves in therapeutic amounts to your daily routine.

3. Can Cause Allergic Reactions

Eugenol is an aromatic liquid present in cloves used in numerous pharmaceutical products. However, eugenol can cause allergies when this compound reacts directly with proteins, resulting in contact dermatitis in sensitive individuals [2].

4. Risk of Toxicity, Especially Clove Oil

In one of the incidences, the toxicity of clove oil is documented. A 2-year-old boy ingested 5 and 10ml clove oil, as a result of which the boy slipped into a coma for a few hours [2]. This underscores the serious nature of concentrated clove oil.

While generally safe as a spice, there is a scope for research on the toxicity of clove oil. Clove oil can potentially cause coma, fits, inhalation pneumonitis, respiratory problems, renal failure, hypoglycemia, and lactic acidosis if ingested in large quantities, especially by children [2].

Precautions

• Consume clove in limited amounts. Though clove has medicinal properties, excess of anything can cause severe aftereffects. For adults, consuming 1-2 whole cloves daily as a spice is generally considered safe.
• Clove oil or cream should be kept out of the reach of children as it may cause fits or liver failure, or kidney failure upon accidental ingestion [2].
• Avoid smoking clove cigarettes in excess. It may result in breathing problems and is detrimental to overall health.
• Always dilute clove essential oil substantially before applying it to the skin or using it in aromatherapy.
• Pregnant or breastfeeding women should use clove only in culinary amounts and consult a doctor before using it medicinally.

Conclusion

Clove (Syzygium aromaticum) is a flower bud used in our day-to-day dishes because of its pleasant aroma and flavour. It is a versatile spice that is not only used in the kitchen but is also used for therapeutic purposes in traditional systems like Ayurveda. It is noted for its potential antibacterial, antiviral, antispasmodic, antimutagenic, and antihypertensive properties. That makes it an all-rounder spice. Clove is highly valued for its traditional role in promoting good oral hygiene. However, due to its potency and potential for interaction with medications, always consult your doctor before using it for medicinal purposes beyond common culinary use.

Frequently Asked Questions (FAQs)

How many cloves are safe per day?

For most healthy adults, consuming 1-2 cloves per day as a spice is generally considered safe. Consuming an excessive amount (e.g., more than 5-6 daily) may lead to digestive discomfort or other side effects. It is advisable to consult a healthcare provider before significantly increasing clove consumption, especially for individuals with existing health conditions.

What disease are cloves used for?

Cloves are commonly used in traditional medicine for their antimicrobial, anti-inflammatory, and antioxidant properties. They are helpful in managing conditions like temporary toothaches, mild digestive issues, and minor infections. Scientific evidence for its use in treating specific diseases is still in preliminary stages.

Who should avoid cloves?

Individuals with bleeding disorders or those taking blood-thinning medications (like Warfarin) should avoid cloves, as they can increase the risk of bleeding [12]. Also, individuals with known allergies to eugenol should avoid them.

Can cloves reduce belly fat?

While cloves can boost metabolism and aid digestion, they are not a magic bullet or direct solution for belly fat reduction. A balanced diet and regular exercise are essential for weight loss. Any effects on weight management are considered supportive, not primary.

What are cloves commonly used for?

Cloves are commonly used as a spice in cooking, for medicinal purposes to relieve temporary toothaches and digestive issues, and in aromatherapy for their soothing scent.

Are cloves safe to consume during pregnancy?

Moderate consumption of cloves as a spice is generally safe during pregnancy. However, pregnant women should consult their doctor before using cloves in medicinal amounts or as a supplement due to a lack of safety data.

Can I use cloves for toothache relief?

Yes, cloves are effective for temporary toothache relief due to their natural analgesic and antimicrobial properties [10]. Applying a diluted mixture of clove oil (1-2 drops mixed with a teaspoon of carrier oil) or placing a whole clove on the affected area can provide temporary relief. However, this does not replace dental treatment.

References

[1] Bai, J., Li, J., Chen, Z., Bai, X., Yang, Z., Wang, Z., & Yang, Y. (2023). Antibacterial activity and mechanism of clove essential oil against foodborne pathogens. Lebensmittel-Wissenschaft Und Technologie [Food Science and Technology], 173(114249), 114249. https://doi.org/10.1016/j.lwt.2022.114249

[2] Batiha, G. E., Alkazmi, L. M., Wasef, L. G., Beshbishy, A. M., Nadwa, E. H., & Rashwan, E. K. (2020). Syzygium aromaticum L. (Myrtaceae): Traditional Uses, Bioactive Chemical Constituents, Pharmacological and Toxicological Activities. Biomolecules, 10(2), 202. https://doi.org/10.3390/biom10020202

[3] Banerjee, K., Madhyastha, H., Sandur, R., V., N T, M., N, T., & Thiagarajan, P. (2020). Anti-inflammatory and wound healing potential of a clove oil emulsion. Colloids and Surfaces. B, Biointerfaces, 193(111102), 111102. https://doi.org/10.1016/j.colsurfb.2020.111102

[4] Pandey, V. K., Srivastava, S., Ashish, N., Dash, K. K., Singh, R., Dar, A. H., Singh, T., Farooqui, A., Shaikh, A. M., & Kovacs, B. (2023). Bioactive properties of clove (Syzygium aromaticum) essential oil nanoemulsion: A comprehensive review. Heliyon, 10(1), e22437. https://doi.org/10.1016/j.heliyon.2023.e22437

[5] Pandey, V. K., Shams, R., Singh, R., Dar, A. H., Pandiselvam, R., Rusu, A. V., & Trif, M. (2022). A comprehensive review on clove (Caryophyllus aromaticus L.) essential oil and its significance in the formulation of edible coatings for potential food applications. Frontiers in Nutrition, 9, 987674. https://doi.org/10.3389/fnut.2022.987674

[6] Mohan, R., Jose, S., Mulakkal, J., Karpinsky-Semper, D., Swick, A. G., & Krishnakumar, I. M. (2019). Water-soluble polyphenol-rich clove extract lowers pre- and post-prandial blood glucose levels in healthy and prediabetic volunteers: an open label pilot study. BMC Complementary and Alternative Medicine, 19(1). https://doi.org/10.1186/s12906-019-2507-7

[7] Kuroda, M., Mimaki, Y., Ohtomo, T., Yamada, J., Nishiyama, T., Mae, T., Kishida, H., & Kawada, T. (2011). Hypoglycemic effects of clove (Syzygium aromaticum flower buds) on genetically diabetic KK-Ay mice and identification of the active ingredients. Journal of Natural Medicines, 66(2), 394–399. https://doi.org/10.1007/s11418-011-0593-z

[8] Carvalho, R. P. R., Lima, G. D. de A., & Machado-Neves, M. (2021). Effect of eugenol treatment in hyperglycemic murine models: A meta-analysis. Pharmacological Research: The Official Journal of the Italian Pharmacological Society, 165(105315), 105315. https://doi.org/10.1016/j.phrs.2020.105315

[9] Liu, J., Zhang, Q., Tao, T., Wang, L.-Y., Sun, J.-Y., Wu, C.-J., & Zou, W.-J. (2022). Health benefits of spices in individuals with chemotherapeutic drug-induced cardiotoxicity. Current Opinion in Pharmacology, 63(102187), 102187. https://doi.org/10.1016/j.coph.2022.102187

[10] Basch, E., Gasparyan, A., Giese, N., Hashmi, S., Miranda, M., Sollars, D., Seamon, E., Tanguay-Colucci, S., Ulbricht, C., Varghese, M., Vora, M., & Weissner, W. (2008). Natural Standard Professional Monograph. Journal of Dietary Supplements, 5(2), 117–146. https://doi.org/10.1080/19390210802335391

[11] Kong, M., Hwang, D., Yoon, S. W., & Kim, J. (2016). The effect of clove-based herbal mouthwash on radiation-induced oral mucositis in patients with head and neck cancer: a single-blind randomized preliminary study. OncoTargets and Therapy, Volume 9, 4533–4538. https://doi.org/10.2147/ott.s108769

[12] Ge, B., Zhang, Z., & Zuo, Z. (2014). Updates on the clinical evidenced Herb‐Warfarin interactions. Evidence-based Complementary and Alternative Medicine, 2014(1). https://doi.org/10.1155/2014/957362