Reviewed by Dr Jessica Gunawan
The Health Perks Of Consuming Black Garlic
Published | 8 min read
Is black garlic better for you than white, raw garlic? Some evidence suggests it might be, but eating more than you should could be problematic. Our experts shine light on the pros and cons of black garlic.
Black garlic might not be something that’s readily available at your local grocery store. But there are plenty of reasons why you may want to go track some down.
Similar to its raw, white counterpart, black garlic boasts a wide variety of health benefits, such as supporting heart, immune, and digestive health. And, thanks to the fermentation process that it undergoes, it may even be more nutritious.
However, you’ll want to read this article with advice from our Traditional Chinese Medicine (TCM) doctor before you eat it daily. Get to know the health benefits of black garlic and tips for how to safely include it in your diet here.
What Is Black Garlic?
Black garlic is white (raw) garlic that has been fermented using high-temperature and high-humidity controlled conditions. This process makes the cloves turn black. It also gives the garlic a milder flavor and a sticky, more delicate consistency.
According to Hong Shuangshaung, a registered Traditional Chinese Medicine (TCM) physician at the Chinese University of Hong Kong’s Medical Center for Integrated Traditional Chinese and Western Medicine, from a TCM perspective, garlic can be divided into two types: garlic and rocambole garlic.
The former is the garlic used for stir-frying, while the latter is the ingredient used for pickled buckwheat heads. When the public refers to the curative effect of eating raw garlic, it mainly refers to garlic.
“Garlic has the functions of warming and invigorating the stomach, digesting food, and detoxifying, which means it can help to dispel the cold in the stomach and help with digestion. Since garlic is warm in nature and has a spicy taste, ancient TCM records state that it has antibacterial effects,” physician Hong noted.
Why Are Black Foods So Important In TCM?
According to Senior TCM physician Brandon Yew from Real Health Medical in Singapore, “Black is the color of the Water element, which corresponds to the kidneys. This means black foods have the propensity to strengthen the kidneys and improve their function. In TCM, the kidneys are the organs that store vital essence, primordial qi, and primordial yin and yang, all of which are important fundamental substances that drive and sustain the physiological functions of the entire body.”
Physician Yew continued, “This explains why TCM is constantly concerned with the health of the kidneys, thus the emphasis of regular consuming black foods to maintain good kidney health for overall well-being.”
Black garlic helps to warm the stomach and promote the spleen’s digestive function, improve qi flow to relieve abdominal bloating, stop diarrhea, reduce swelling and dispel toxins to heal skin boils and sores. It also kills parasitic worms to treat skin infections. Physician Yew stated, “According to TCM pharmacological theory, black garlic is warm in nature, with pungent, sweet and sour taste profiles and mechanistic properties.”
Health Benefits Of Black Garlic
Black garlic contains a wide variety of health benefits, including:
1. Contains Ample Antioxidants
Antioxidants are molecules that stabilize free radical toxins and reduce inflammation to keep cells healthy. Some research indicates that black, aged garlic contains higher levels of antioxidants than raw garlic.
According to one study, the fermentation processes enhance the level of polyphenol antioxidant compounds found in garlic. Another study found that antioxidant levels in black garlic peaked on the 21st day of aging.
2. May Improve Blood Sugar Levels
Several animal studies have shown the potential anti-diabetic properties of black garlic. A 2019 study found that the “good” bacteria found in fermented garlic boosts its antioxidant capacity to reduce the risk of gestational diabetes. However, more research needs to be done on the glucose-reducing effects of black garlic on humans.
3. May Reduce Cholesterol Levels
One study found that supplementing with aged black garlic reduced atherogenic markers by boosting HDL (good cholesterol) and reducing LDL (bad cholesterol). Thus, researchers determined that it may have a cardioprotective in patients with mild hypercholesterolemia.
4. May Protect Brain Health
Several animal studies have shown that black garlic contains neuroprotective properties that may reduce the risk of Alzheimer’s and Parkinson’s diseases. It may also reduce damage from stroke and brain injuries and improve brain markers that aid in cognitive function and memory. Again, more studies need to be conducted on humans to support this evidence.
5. Aids Digestive And Immune Health
Black garlic contains healthy prebiotic and probiotic bacteria that may aid digestive and immune health. One study found that it improves gastrointestinal function and motility to promote defecation and eliminate constipation. Another study stated that it enhances immunity by boosting the activity of natural killer (NK) cells. This may provide anti-tumor benefits.
Additionally, black garlic contains natural anti-bacterial properties that may aid in immune health by helping to fight infections. One study found that aged garlic contains more anti-bacterial properties than fresh, raw garlic.
6. May Support Weight Loss
Several studies have indicated that black garlic contains anti-obesity effects. It has been shown to reduce body weight gain and obesity in rats fed a high-fat diet. More studies are needed to determine its effectiveness in humans.
Potential Side Effects
Despite its numerous health benefits, black garlic may not be suitable for everyone. This is especially true if you are considering taking it to reduce high blood pressure.
Physician Hong explains, “There are too many studies on garlic, but the quality of the research differs. For example, is the number of people tested sufficiently? The test methods are different, so even if there are research reports, they can only be used as reference.”
“From a TCM perspective, even if many studies indicate that garlic can help lower blood pressure, we cannot be fully dependent on just one ingredient to solve this health issue. Moreover, garlic is warm in nature and has a spicy taste. If you eat too much raw food for a long time, your body will become hot and prone to heatiness. This will then cause imbalance in the constitution and result in other physical problems,” physician Hong continued.
Physician Yew warned against using black garlic if you have certain conditions. He stated, “As black garlic is warm in nature, it is only suitable for people of yang (warming energy)-deficient or yin-excess cold body constitution. It’s contraindicated for people of yin (body fluids and cooling energy)-deficient or yang-excess hot body constitution, especially those suffering from frequent headaches and migraine, inflammation of the eyes, mouth, tongue, throat, gums, and teeth.”
Due to its pungency, it is contraindicated for people with body odor. Black garlic also has strong qi-propelling effect, hence it’s contraindicated in pregnant women.
Avoid Eating It Raw
Physician Hong pointed out that eating raw garlic may not be good for high blood pressure patients. “From a TCM perspective, the principle of treating diseases is mainly to regulate the body constitution and balance yin and yang. Therefore, every type of food material and medicine should be determined according to the individual’s body constitution. People with high blood pressure mostly have a heaty constitution. Eating too much raw garlic that’s warm in nature will only cause more dryness in the body.”
Does It Have Laxative Effects?
Eating black garlic can help relieve constipation, due to its fiber content. However, some people worry about garlic’s laxative effect. Physician Hong stated, “The laxative effect is the same as eating fresh vegetables, and there is not a huge difference.”
Use With Caution If You Have Ulcers Or GERD
According to physician Yew, eating black garlic after meals may help promote digestion. He stated, “As black garlic has a sour taste profile from the fermentation process, it stimulates the production of gastric acid to improve digestion. Hence, it is strongly advised to consume black garlic after meals. But it has to be used with extra caution, or to be totally avoided in people suffering from gastric hyperacidity, acid reflux or GERD, active gastritis, and gastric ulcers.”
How Much Should You Eat?
Black garlic is similar to garlic. Its effect will be diminished after being cooked at a high temperature. Therefore, eating dishes made with it may not help in terms of long-term health benefits. And, whether it be raw garlic or black garlic, it is not advisable to overeat it. So, how much is too much?
Physician Hong stated, “Generally speaking, even for people with a cold constitution, eating five to ten bulbs a day is too much. In fact, one to two bulbs a day is enough.” Some people opt to leave it out of their meals altogether and take a black garlic supplement instead.
Physician Yew recommends, “Since black garlic is to be taken as a health supplement rather than a form of medicine, one whole garlic bulb per day is good enough. As the overall effects of garlic are stimulative, it’s best to consume it during the day like after breakfast or lunch, not during the night after dinner for it may disrupt your sleep.”
If you’re considering taking it in supplement form, then consider finding a brand that uses 100% patented Aomori Japanese Garlic, which undergoes a process allowing it to contain 13 times more polyphenol and 8 times more natural S-allyl Cysteine (SAC) content than native garlic.
Final Thoughts
No matter the type, the smell and taste of garlic may not be acceptable for everyone. There are many alternatives to choose from. Physician Hong stated, “If you want to invigorate the stomach and improve digestion, use fried malt or grain sprout decoction instead. For a warming effect, use galangal to reduce gastrointestinal irritation. As for those with constipation or obstructed defecation, cumin can be added as a seasoning when cooking. This can help with intestinal movement and excretion.”
It’s best to first consult a licensed TCM practitioner for a thorough assessment of your body constitution and suitability for taking black garlic. If suitable, you will get professional advice or guidance on how to best consume black garlic to reap maximal benefits.
References
- PubMed. Journal of Food Chemistry. 2016. Evolution of some physicochemical and antioxidant properties of black garlic whole bulbs and peeled cloves.
- PubMed. Journal of Molecules. 2014. Physicochemical and antioxidant properties of black garlic.
- PubMed. Journal of Bioscience Reports. 2019. Lactobacillus bulgaricus improves antioxidant capacity of black garlic in the prevention of gestational diabetes mellitus: a randomized control trial.
- PubMed. Journal of Nutrition. 2014. Reduction of blood lipid parameters by a 12-wk supplementation of aged black garlic: a randomized controlled trial.
- PubMed. Journal of Food Research International. 2018. Extracts of black garlic exhibits gastrointestinal motility effect.
- Medicinal and Aromatic Plant Science and Biotechnology. 2010. Black Garlic Extracts Enhance The Immune System.
- PubMed. Journal of Food Science Biotechnology. 2018. Antioxidant and antimicrobial activities of fresh garlic and aged garlic by-products extracted with different solvents.
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