Cloves, Clove Oil, and Eugenol: Culinary and Medicinal Uses
An Aromatic and Useful Spice
Cloves are a dark brown, aromatic spice that can add an interesting flavour to foods and drinks. A large quantity of cloves can be overpowering, but a small amount can enhance a dish. Cloves are useful either on their own or when combined with other spices. Meats, stews, vegetables, cakes, fruits, teas, and infusions can all benefit from the addition of the spice.
The flavour of cloves is provided by their oil. A chemical called eugenol makes up seventy to ninety percent of the oil and is the chief substance responsible for the aroma and taste of cloves. Eugenol may also act as an analgesic in the mouth, since it has the ability to temporarily block pain by numbing tissues. Clove oil has been used to ease the discomfort of toothache for hundreds of years. The oil has drawbacks as well as benefits, however. It's important to be aware of these.
The Clove Tree
Cloves are the dried flower buds of the clove tree, which has the scientific name Syzygium aromaticum. The fresh buds are green at first and then become pink. They turn red-brown as they're dried. The tree is native to the Moluccas, or the Maluku Islands. The islands are part of Indonesia and are sometimes known as the Spice Islands. Historically, the Moluccas were a very popular source of cloves, nutmeg, pepper, and mace.
Today cloves are cultivated in several countries, including Indonesia, Zanzibar, and Madagascar. The spice is sold as intact flower buds and as a ground powder. Like other spices, cloves lose some of their flavour if they’re ground long before they're used.
The clove tree belongs to the myrtle family of plants. The family is known for its production of essential oils. It includes the plants that produce allspice, eucalyptus oil, and the bay rum oil that is used in cologne and aftershave lotion.
Clove Nails and Ground Spice
The word "clove" comes from "clavus", the Latin word for nail. The name reflects the appearance of the dried flower buds, which look somewhat like rusty nails. The bud at the head of the nail is surrounded by four sepals.
Cloves have an intense flavour. They also taste pungent and only slightly sweet. I like to mix them with a sweeter spice, such as cinnamon, when I add them to food or drinks.
Since cloves are generally eaten in small quantities, a single serving doesn't provide many nutrients. A very important exception is manganese, however. One teaspoon of ground cloves provides about thirty percent of our daily manganese requirement.
Clove nails are hard structures and are quite difficult to grind. An electric grinder is needed to break them up. Sometimes it isn't necessary to grind the intact cloves, though. For example, in the chai tea recipe described in one of the videos below, the cloves are boiled in liquid to release their flavour and are then filtered out of the liquid.
A Flavour Enhancer
Cloves work very well in spiced drinks and spice cakes. They provide a nice taste to stewed fruit and grains as well. They are also a popular addition to curries, vegetable dishes, and beans. They're sometimes used to "stud" meat and vegetables such as onions. Whole cloves are pushed into the food so that just the buds are visible. This process adds flavour to the food. The cloves are removed once the food is cooked.
Cloves are a traditional component of chai tea, or masala chai as it's sometimes called. This tasty and aromatic beverage originated in India but is now popular in many other parts of the world, too. It's made from black tea and mixed spices. The recipe usually includes milk and a sweetener as well. The mixture of spices in the drink varies in composition but traditionally contains cloves, cinnamon, nutmeg, ginger, star anise, peppercorns, and green cardamom pods.
Cloves are also a traditional part of the spice mixture known as garam masala. The mixture has a similar composition to the one used in masala chai and also varies slightly in composition.
Clove Oil and Toothache
Oil of cloves, or clove oil, is extracted from the buds, leaves, or stems of the clove tree. It's pale yellow in colour and is rich in eugenol. The oil is far more potent than clove buds or the ground spice. It shouldn't be swallowed or brought into deliberate contact with the gums, tongue, or lips because it may damage the tissue that it touches. Many people report that clove oil relieves toothache pain, however. The oil is sold as an over-the-counter medicine in some pharmacies.
Clove oil must be placed directly on a painful tooth without touching the rest of the mouth. The oil can be applied with a cotton swab. If you find that it helps your toothache, remember that it's only a temporary solution. You need to visit a dentist very soon to get the cause of the toothache treated.
I've never tried using clove oil for a toothache, but I applied ground cloves to my gum when I had a root problem and they did relieve my pain temporarily. Even ground cloves can be irritating to gums if too much is used or if the cloves are used too often.
Some people apply clove oil diluted with olive oil to painful gums. (It's very important to dilute the clove oil in this situation.) Once again, it's great if you find that this mixture removes your gum pain, but you need to seek a dentist's advice as soon as possible to get the problem treated. Using cloves repeatedly increases the chance of tissue damage from the oil. In addition, even though oral pain may weaken or temporarily disappear with cloves treatment, the infection in the tooth or gums may continue to get worse.
All of the containers of clove oil that I've seen in stores have a warning that the oil mustn't come into contact with the gums. This may be hard to avoid, since saliva will likely transport some of the oil through the mouth when it's applied to a tooth. This needs to be kept in mind.
Dangers of Clove Oil
Ground cloves are considered to be safe if eaten in moderate quantities. Inhaling smoke from clove cigarettes can cause breathing problems and damage the lungs, however.
Clove oil is a potentially dangerous substance. It can do more in our body than simply damage tissue. The ingestion of a large quantity of the oil can cause a coma, seizures, liver damage, and kidney damage. Other detrimental effects of clove oil include nausea, vomiting, stomach pain, diarrhea, and a rapid heartbeat. Clove oil is also thought to delay blood clotting and shouldn't be used before surgery.
It's very important to keep the oil away from children, since even a small amount may have serious effects inside a child's body. Pregnant women and nursing mothers are generally advised to avoid using clove oil and to eat cloves only in the amount that would normally be added to food.
Frequent and repeated application of clove oil in the mouth or on the gums can sometimes cause damage to the gums, tooth pulp, skin, and mucous membranes.— MedlinePlus (NIH)
Remember that ground cloves contain clove oil. The ground spice is less potent than the oil, but it can eventually damage tissue if it's used too often.
An Antibacterial Oil
Clove oil has been found to have antimicrobial activity against certain harmful bacteria and yeasts in food, but not (so far) against harmful oral bacteria while they are inside the mouth.
When looking at research reports, it's important to notice whether an experiment was done "in vitro" (in lab equipment) or "in vivo" (in living things). Many substances have been found to work in lab glassware but not inside living bodies, where the substance is diluted, removed by body fluids, broken down, inhibited by other chemicals, or not absorbed. In addition, a substance may work inside lab animals but not inside humans, whose bodies may not work in quite the same way as the bodies of animals.
Several researchers have found that clove oil fights harmful oral bacteria in vitro, which is a hopeful sign for the future. Some of the research is quite old, however. It would be wonderful if scientists are eventually able to create a safe and effective clove oil medicine to fight harmful bacteria in our mouths as well as relieve pain.
Eugenol and Its Uses
Eugenol is the most abundant ingredient in clove oil and is responsible for both the beneficial and the harmful effects of the oil. It's found in cinnamon, nutmeg, and allspice oils as well as in clove oil.
Eugenol is used in fragrances and perfumes because of its aromatic scent. It's sometimes used by dentists to numb the gums or to make a temporary filling when mixed with zinc oxide. However, eugenol use is less common in dentistry today than it was in the past. The substance has caused allergic reactions and contact dermatitis in some people.
Eugenol is also used as an insecticide to kill pests, especially those found in homes and gardens. It's appreciated because of its fast action when used at the appropriate dose and its relative safety for humans compared to some other chemicals. The insecticide is often sold as "eugenol oil". One problem with eugenol oil is that some pests require a higher concentration of eugenol to kill them than others. Since eugenol is responsible for the harmful effects of clove oil in humans, it's very important to be careful when using it as a pesticide.
Do you add cloves to foods and/or drinks?
Adding Cloves to the Diet
Whole and ground cloves provide a delicious taste to foods and drinks when they're combined with other spices. Ground cloves are a useful addition to a kitchen spice collection. They have a strong taste, however, so it's best to use them in small quantities, especially when someone isn't used to the spice.
Cloves are safe when used in reasonable quantities. Large amounts of cloves and isolated clove oil and eugenol need to treated with care. They may be helpful, but they're potentially dangerous as well.
This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
© 2012 Linda Crampton