Black garlic is garlic (Allium sativum L.) that has been aged in a hot and humid environment.
Fresh garlic is exposed to temperatures between 140-194 degrees Fahrenheit (60-90 degrees Celcius) and humidity levels between 70-90% for several weeks. The result is a deep brownish-black-colored garlic with a chewy texture and sweet taste that’s higher in antioxidants than normal garlic.
Studies show that consuming black garlic may benefit health in several ways, including improving heart disease risk factors such as cholesterol and blood pressure.
Design by Health
Black garlic is an excellent source of protective plant compounds and contains higher levels of certain antioxidants than regular garlic. Antioxidants are substances that protect against cellular damage by neutralizing reactive compounds called free radicals.
There are multiple types of antioxidants concentrated in garlic and the aging process used to create black garlic increases levels of some of these substances. For example, studies show that black garlic contains up to 10 times more phenolic compounds, such as hydroxycinnamic acid, and up to eight times more flavonoid compounds compared to regular garlic.
Black garlic is also a concentrated source of sulfur-containing phytocehmicals such as γ−glutamyl-S-methyl-L-cysteine sulfoxide (GSMCS) and S-allylmercapto-L-cysteine (SAMC), which have powerful cellular-protective properties.
Not only is black garlic higher in certain protective substances than regular garlic, but studies show that the heat treatment used to produce black garlic increases the bioaccessibility of the sulfur compounds in it, meaning they’re more easily absorbed by your body.
The sulfur compounds found in garlic, including black garlic, are thought to be responsible for most of garlic’s health benefits. These substances have been shown to have powerful anti-inflammatory and antioxidant effects and may protect against certain health conditions. Studies show that people who regularly consume garlic have lower rates of certain diseases, such as gastrointestinal cancers.
Multiple studies have shown that diets rich in garlic are associated with lower rates of heart disease risk factors such as hypertension (high blood pressure), high cholesterol, and atherosclerosis—the thickening or hardening of the arteries caused by plaque buildup.
Due to its exceptionally high levels of antioxidant and anti-inflammatory compounds, black garlic may offer even more benefits for heart health. Studies show that this special type of garlic may effectively lower blood pressure and blood lipid levels and reduce atherosclerosis.
One small study of 62 people found that consuming four cloves of black garlic daily for 12 weeks had significantly increased levels of Apolipoprotein A (Apo)A1, a protein that helps high-density lipoprotein (HDL) cholesterol remove low-density lipoprotein (LDL) cholesterol (“bad” cholesterol”) from the bloodstream. They also had significantly reduced cellular adhesion molecules, which are proteins that allow cells to stick to one another and their surroundings. These proteins play a key role in the development and progression of atherosclerosis.
Study findings also suggest that extract derived from black garlic could boost levels of heart-protective HDL cholesterol and reduce blood pressure.
Black garlic may also improve heart function in people with pre-existing heart disease. One study found that treatment with 20 grams (g) of black garlic per day for six months improved heart function, including the amount of oxygen-rich blood pumped by the heart, in people with heart failure compared to a control group.
The black garlic treatment increased blood levels of the antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), suggesting that black garlic helps boost the body’s antioxidant defenses, which may improve the health and functioning of the heart.
Garlic, including black garlic, is low in calories and, because it’s usually consumed in small portions, it’s not a good source of vitamins or minerals.
Here is the nutrition breakdown for three cloves of garlic:
- Calories: 13.4
- Protein: < 1 gram (g)
- Fat: < 1 g
- Carbohydrate: 2.98 g
- Fiber: < 1 g
- Vitamin C: 2.81 milligrams (mg), or 3% of the Daily Value (DV)
In normal doses, garlic, including black garlic, provides small amounts of certain nutrients, such as vitamin C and potassium, but not enough to significantly contribute to your daily nutrient intake. For example, three cloves of garlic provide 3% of your daily needs for vitamin C, a powerful antioxidant that plays important roles in your immune system, skin, and more.
When consumed in normal amounts, garlic, including black garlic, is safe for most people and isn’t associated with major health risks. That said, black garlic isn’t safe for people who are allergic to garlic. Consuming black garlic in large amounts may also lead to symptoms such as bad breath, body odor, nausea, vomiting, and gas.
Black garlic supplements, such as black garlic extract, are also considered safe. However, garlic has blood-thinning properties, and high-dose garlic supplements may be unsafe for people on blood-thinning medications and people with blood clotting disorders. For this reason, it’s best to check with your healthcare provider before taking garlic supplements if you’re at an increased risk for bleeding.
Also, if you’re pregnant or breastfeeding, you should check with your healthcare provider before ingesting large amounts of black garlic or taking black garlic supplements.
Lastly, improperly aged black garlic can lead to the development of Clostridium botulinum (C. botulinum) spores. C. botulinum spores produce dangerous toxins that can harm health when ingested. Because of this health risk, experts advise against using household appliances such as slow cookers and rice cookers to make black garlic.
The aging process used to produce black garlic causes a chemical reaction called the Maillard reaction, which results in a dark-colored garlic with a sweeter, less pungent taste than regular garlic.
In addition to its distinctive flavor, black garlic has a chewy and sticky texture, which sets it apart from regular garlic.
Here are a few ways to use black garlic:
- Add it to soups and stews for a rich and unique flavor
- Use it to top dishes like pizza and pasta
- Smear black garlic on bread for a flavorful sandwich spread
- Blend black garlic into sauces, dressings, and marinades
- Add black garlic to butter and olive oil to make delicious spreads and dips
You can purchase black garlic in several forms, including whole bulbs, cloves, purees, and powders. Black garlic products can be found in specialty grocery stores and purchased online.
Black garlic is an aged garlic product that’s made by exposing fresh garlic to high heat and humidity levels for several weeks. It has a sweet taste and chewy texture and is packed with health-promoting plant compounds.
Some studies show that consuming black garlic may help support the body’s antioxidant defenses and boost heart health by protecting against heart disease risk factors such as atherosclerosis and high blood pressure.
Black garlic has a unique flavor that can add depth and interest to your favorite dishes such as pastas, soups, and sandwiches, making it a versatile ingredient to keep in your kitchen.