Cloves are the flower buds of the clove tree, an evergreen also known as Syzygium aromaticum ().
Found in both whole and ground forms, this versatile spice can be used to season pot roasts, add flavor to hot beverages and bring spicy warmth to cookies and cakes.
You may know cloves as one of the main ingredients in gingerbread baked goods or a staple spice in Indian cuisine.
In addition to their sweet, aromatic flavor, cloves are known for their potent medicinal properties.
In fact, animal studies have found that the compounds in cloves may have several health benefits, including supporting liver health and helping stabilize blood sugar levels (, ).
This article reviews 8 of the most impressive health benefits of eating cloves.
1. Contain Important Nutrients
Cloves contain fiber, vitamins and minerals, so using whole or ground cloves to add flavor to your food can provide some important nutrients.
One teaspoon (2 grams) of ground cloves contains ():
- Calories: 21
- Carbs: 1 gram
- Fiber: 1 gram
- Manganese: 30% of the RDI
- Vitamin K: 4% of the RDI
- Vitamin C: 3% of the RDI
Fiber can help prevent constipation and promote regularity, vitamin C may help strengthen your immune system and vitamin K is an important nutrient for blood clotting (, , ).
Meanwhile, manganese is an essential mineral for maintaining brain function and building strong bones (, ).
In addition to the nutrients listed above, ground cloves contain small amounts of calcium, magnesium and vitamin E ().
Summary: Cloves are low in calories and provide some fiber, manganese, vitamin K and vitamin C.
2. High in Antioxidants
As well as containing several important vitamins and minerals, cloves are rich in antioxidants ().
Antioxidants are compounds that reduce oxidative stress, which can contribute to the development of chronic disease ().
Cloves also contain a compound called eugenol, which has been shown to act as a natural antioxidant.
In fact, a test-tube study found that eugenol stopped oxidative damage caused by free radicals five times more effectively than vitamin E, another potent antioxidant ().
In addition to eugenol, ground cloves contain vitamin C.
Vitamin C acts as an antioxidant in your body and helps neutralize free radicals, which are compounds that can build up and cause harmful oxidative stress (, ).
Including cloves in your diet along with other antioxidant-rich foods can help improve your overall health.
Summary: Cloves are high in antioxidants, including eugenol and vitamin C, both of which can help reduce oxidative stress.
3. May Protect Against Cancer
Some research shows that the compounds found in cloves can help protect against cancer.
One test-tube study found that clove extract helped stop the growth of tumors and promoted cell death in cancer cells ().
Another test-tube study had similar results, showing that concentrated amounts of clove oil caused cell death in 80% of esophageal cancer cells ().
The eugenol found in cloves has also been shown to have anti-cancer properties.
A test-tube study found that eugenol effectively promoted cell death in cervical cancer cells ().
However, keep in mind that these test-tube studies used very concentrated amounts of clove extract, clove oil and eugenol.
Eugenol is toxic in high amounts and overdosing on clove oil may cause liver damage, especially in children. Further research is needed to determine how lower amounts may affect humans ().
Summary: Test-tube studies show that the compounds in cloves may reduce cancer cell growth and promote cancer cell death. More research is needed to confirm these effects in humans.
4. Can Kill Off Bacteria
Cloves have been shown to have antimicrobial properties, meaning they can help stop the growth of microorganisms like bacteria ().
One test-tube study showed that clove essential oil was effective at killing off three common types of bacteria, including E. coli, a strain of bacteria that can cause cramps, diarrhea, fatigue and even death ().
What’s more, the antibacterial properties of cloves could even help promote oral health.
In one test-tube study, the compounds extracted from cloves were found to stop the growth of two types of bacteria that contribute to gum disease ().
Another study in 40 people tested the effects of an herbal mouthwash consisting of tea tree oil, cloves and basil.
After using the herbal mouthwash for 21 days, they showed improvements in gum health, as well as the amount of plaque and bacteria in the mouth ().
In combination with regular brushing and proper oral hygiene, the antibacterial effects of cloves may benefit your oral health.
Summary: Studies show that cloves may promote oral health, thanks to their antimicrobial properties, which may help kill harmful bacteria.
5. May Improve Liver Health
Studies show that the beneficial compounds in cloves could help promote liver health.
The compound eugenol may be especially beneficial for the liver.
One animal study fed rats with fatty liver disease mixtures containing either clove oil or eugenol.
Both mixtures improved liver function, reduced inflammation and decreased oxidative stress ().
Another animal study showed that the eugenol found in cloves helped reverse signs of liver cirrhosis, or scarring of the liver ().
Unfortunately, research on the liver-protecting effects of cloves and eugenol in humans is limited.
However, one small study found that taking eugenol supplements for one week decreased levels of GST, an enzyme involved in detoxification that’s often a marker of liver disease (, ).
Cloves are also high in antioxidants, which may help prevent liver disease due to their ability to help decrease oxidative stress ().
Nevertheless, keep in mind that eugenol is toxic in high amounts. One case study in a 2-year-old boy showed that 5 to 10 ml of clove oil caused serious liver damage ().
Summary: Some studies show that cloves and the compounds they contain may help reduce oxidative stress and protect the liver.
6. May Help Regulate Blood Sugar
Research shows that the compounds found in cloves may help keep blood sugar under control.
An animal study found that clove extract helped moderate blood sugar increases in diabetic mice ().
Another test-tube and animal study looked at the effects of clove extract and nigericin, a compound found in cloves, both on human muscle cells and in diabetic mice.
Cloves and nigericin were found to increase the uptake of sugar from the blood into cells, increase the secretion of insulin and improve the function of cells that produce insulin ().
Insulin is a hormone responsible for transporting sugar from your blood into your cells. The proper functioning of insulin is essential for maintaining steady blood sugar levels.
In combination with a balanced diet, cloves could help keep your blood sugar levels in check.
Summary: Test-tube and animal studies have shown that the compounds in cloves may help promote insulin production and lower blood sugar.
7. May Promote Bone Health
Low bone mass is a condition that affects an estimated 43 million older adults in the US alone ().
It can lead to the development of osteoporosis, which may increase the risk of breaks and fractures.
Some of the compounds in cloves have been shown to help preserve bone mass in animal studies.
For example, an animal study found that clove extract high in eugenol improved several markers of osteoporosis and increased bone density and strength ().
Cloves are also rich in manganese, providing an impressive 30% of the daily recommended amount in just 1 teaspoon (2 grams) of ground cloves ().
Manganese is a mineral that’s involved in the formation of bone and incredibly important to bone health.
An animal study found that taking manganese supplements for 12 weeks increased bone mineral density and bone growth ().
However, current research on the effects of cloves on bone mass is mostly limited to animal and test-tube studies. More research is needed to determine how it may affect bone formation in humans.
Summary: Animal studies show that clove extract and manganese may help increase bone mineral density. More research is needed to confirm these effects.
8. May Reduce Stomach Ulcers
Some research indicates that the compounds found in cloves could help treat stomach ulcers.
Also known as peptic ulcers, stomach ulcers are painful sores that form in the lining of the stomach, duodenum or esophagus.
They are most commonly caused by reductions in the protective lining of the stomach that are due to factors like stress, infection and genetics ().
In one animal study, the essential oil from cloves was shown to increase the production of gastric mucus ().
Gastric mucus functions as a barrier and helps prevent erosion of the stomach lining from digestive acids ().
Another animal study found that clove extract helped treat stomach ulcers and had effects similar to several anti-ulcer medications ().
Though the anti-ulcer effects of cloves and their compounds may be promising, further studies are needed on their effects in humans.
Summary: Some animal studies show that clove extract and clove oil may increase the production of gastric mucus and help protect against stomach ulcers. More research in humans is needed.
The Bottom Line
Cloves have many potential health benefits, including keeping blood sugar in check and helping block the growth of bacteria.
As with many healthy foods, they’re most effective when included as part of a healthy and balanced diet. Try integrating a few servings of cloves per week into your meals.
You can easily incorporate ground cloves into many dishes. They’ll bring a warm, distinctive flavor to desserts, curries or chutneys.
You can also simmer whole cloves in boiling water for 5–10 minutes to make a soothing cup of clove tea.
Cloves are delicious and may provide many important health benefits.