By Dr. Mercola
Of all the foods Mother Nature provides, few foods offer more of a “botanical bonanza” for your health than garlic. Garlic is a bulbous root closely related to the onion, mentioned in historical documents dating back 5,000 years—before its fame wafted into the rest of the known world.
Speaking of wafting, garlic’s nickname “stinking rose” is well-deserved due to its undeniably pungent aroma that some find objectionable, but others find intoxicating.
Numerous studies show garlic’s amazing health potential in nearly every area of your body, from clogged arteries to gangrene to preventing insect bites and ear infections. There is even evidence that garlic is able to help slow your aging process. When it comes to this magical bulb, what’s not to love?
Garlic Epitomizes a ‘Heart Healthy Food’
Like so many other complex plant foods, garlic contains a wide range of phytocompounds that act together to produce a wide variety of responses in your body. Garlic is rich in manganese, calcium, phosphorus, selenium, and vitamins B6 and C, so it’s beneficial for your bones as well as your thyroid.
Garlic also helps your body cleanse itself of heavy metals, such as lead, mercury, cadmium, and arsenic.1 Green Med Info has also assembled a list of studies demonstrating garlic's positive effects for more than 150 different diseases.2 In general, its benefits fall into four main categories:
- Reducing inflammation (reduces risk of osteoarthritis as mentioned in the video above)
- Boosting immune function (antibacterial, antifungal, antiviral, and antiparasitic properties)
- Improving cardiovascular health and circulation (protects against clotting, retards plaque, improves lipids, and reduces blood pressure)
- Toxic to 14 kinds of cancer cells (including brain, lung, breast, and pancreatic)
The fact that garlic is so effective in fighting multiple types of cancer is probably related to its potent antioxidant effects. Garlic contains the precursors to allicin—a compound I’ll be discussing in detail shortly. Allicin is one of the most potent antioxidants from the plant kingdom.
In fact, researchers have determined that sulfenic acid, produced during the rapid decomposition of allicin, reacts with and neutralizes free radicals faster than any other known compound—it’s almost instantaneous when the two molecules meet. And as an anti-infective, garlic has been demonstrated to kill everything from candida to herpes, MRSA, drug-resistant tuberculosis, and even HIV.
Garlic’s Secret Weapon: Allicin
Researchers have found that allicin is an effective natural "antibiotic" that can eradicate even antibiotic-resistant bugs. An added benefit is that the bacteria appear incapable of developing a resistance to the compound. However, the garlic must be fresh because the active agent is destroyed in less than an hour after smashing the garlic clove.
Garlic technically does not contain allicin, but rather, it contains two agents in separate compartments of the clove that react to form the sulfur-rich compound allicin when the plant needs it: alliin and an enzyme called allinase. So, what makes them react?
Garlic has a robust defense system to protect itself from insects and fungi. It enzymatically produces allicin within seconds when it is injured. The crushing of its tissues causes a chemical reaction between the alliin and the allinase, and allicin is produced—nature’s “insecticide.” This is what makes garlic such a potent anti-infective, as well as what produces that pungent aroma when you cut into it.
But allicin is short-lived, lasting less than an hour. Therefore, cooking, aging, crushing, and otherwise processing garlic causes allicin to immediately break down into other compounds, so it’s difficult to get allicin up to biologically active levels in your body.3
Plus, an Army of Sulfur-Rich Phytochemicals
More than 100 different compounds have been identified in garlic, some of which come from the rapid breakdown of allicin itself. The absorption, metabolism, and biological effects of all these compounds are only partially understood. So, although garlic is known to possess a wealth of health benefits, we still do not know exactly which benefits come from which compounds, what compounds get into which tissues, etc.
As powerful as allicin is as an anti-infective, it only makes sense that garlic’s other health effects come from the synergism of those many OTHER compounds. This is a complicated topic, and if you want to explore it further, the Oregon State’s Linus Pauling Institute has a comprehensive article in their online Micronutrient Information Center.4
What About Garlic Supplements?
Most commercial garlic supplements perform quite poorly when it comes to actually being able to form allicin in your body. Allinase is destroyed by the strong acids in your stomach, which is why most supplements are “enteric coated,” to keep them from dissolving until they enter your small intestine. But most supplements tested produce only minimal amounts of allicin under these tough digestive conditions. Many garlic supplements list “allicin potential” on the label, which refers to how much allicin could be formed when alliin is converted, not how much allicin is actually produced.
Claims of actual “allicin release” may be more reliable, but with digestive conditions being so individual and variable, I would be less than confident you’re getting what the label promises. Therefore, when it comes to garlic, I believe it is much better to eat the real food rather than rely on a supplement. And due to the fact that allicin won’t be formed unless the garlic clove is crushed, you have to crush it before swallowing to get the full benefit, or chew it up. If chewing up raw garlic is a bit too hardcore for you, then you may have cause for celebration: aged black garlic to the rescue!
Aged Black Garlic Has Arrived!
Developed in Korea, black garlic has been gaining popularity among Western foodies for several years now, but it has recently caught the eye of the health-minded due to studies revealing its impressive nutritional properties. Black garlic is produced by “fermenting” whole bulbs of fresh garlic in a humidity-controlled environment in temperatures of about 140 to 170 degrees F for 30 days. No additives, no preservatives... just pure garlic. Once out of the heat, the bulbs are then left to oxidize in a clean room for 45 days. This lengthy process causes the garlic cloves to turn black and develop a soft, chewy texture with flavors reminiscent of “balsamic vinegar” and “soy sauce,” with a sweet “prune-like” taste. Aficionados claim the flavor will impress even the most avid garlic-hater, as the pungency and spiciness is gone.5
Although the process is consistently described as “fermentation,” it really isn’t that in the strictest sense, as the transformation does not involve microbial processes—specifically, enzymatic breakdown and the Maillard Reaction are responsible for the caramelization of the sugars, dark color and deep, complex flavor profile.6 As the pearly white cloves slowly transition into their final black appearance, compounds in the fresh garlic transform into a whole new range of compounds. Compared to fresh garlic, black garlic is low in alliin but it is astonishingly high in other antioxidants!
Double the Antioxidants of Fresh Garlic
In a 2009 mouse study, Japanese researchers found that black garlic was more effective than fresh garlic in reducing the size of tumors. The study was published in the journal Medicinal and Aromatic Plant Science and Technology.7 In another study, black garlic was found to have twice the antioxidant levels as fresh—the aging/fermenting process appears to double the antioxidants. Black garlic is packed with high concentrations of sulfurous compounds, especially one in particular: s-allylcycteine (SAC).8 Science has shown a number of health benefits from SAC, including inhibition of cholesterol synthesis.9
Perhaps this is why Mandarin oil painter Choo Keng Kwang experienced a complete reversal of his psoriasis after just four days of eating half a bulb of black garlic a day—this, after trying countless medically prescribed skin creams that were all complete failures.
An advantage of SAC is that it is well-absorbed and much more stable than allicin and 100 percent bioavailable. Researchers are confident it plays a significant role in garlic’s overall health benefits.10 Be mindful, however, that black garlic’s benefits may be more effective than fresh garlic for some conditions but not others, given its allicin content is low. For example, I suspect it may not be as effective if you have an infection, as allicin is thought to be the primary anti-infective agent in garlic, and fresh garlic is higher in allicin than black. According to Blue Fortune Farm (which admittedly sells black garlic), black garlic has the following favorable nutrient profile:11
Sprouted Garlic Is Fresh Garlic, Multiplied...
Do you toss your garlic into the compost pile when it begins sending up those bright green shoots? You might want to stop doing that after you read the most recent report about sprouted garlic. In an article published in the Journal of Agricultural and Food Chemistry,12 garlic sprouted for five days was found to have higher antioxidant activity than fresher, younger bulbs, and it had different metabolites, suggesting it also makes different substances.
Researchers concluded that sprouting your garlic might be a useful way to improve its antioxidant potential. Extracts from this garlic even protected cells in a laboratory dish from certain types of damage.13 This isn’t really surprising when you consider the nutritional changes that typically occur in plants when they sprout. When seedlings grow into green plants, they make many new compounds, including those that protect the young plant against pathogens. The same thing is likely happening when green shoots grow from old heads of garlic.
Growing your own sprouts is a great way to boost your nutrition, especially if you have limited space for gardening. Sprouted seeds of various kinds can contain up to 30 times the nutrition of homegrown organic vegetables and allow your body to extract more vitamins, minerals, amino acids, and essential fats from the foods you eat. If you want more information, please refer to our earlier article about sprouting. While you can sprout a variety of different beans, nuts, seeds, and grains, sprouts in general have the following beneficial attributes:
- Support for cell regeneration
- Powerful sources of antioxidants, minerals, vitamins, and enzymes that protect against free radical damage
- Alkalinizing effect on your body, which is thought to protect against disease, including cancer (as many tumors are acidic)
- Abundantly rich in oxygen, which can also help protect against abnormal cell growth, viruses, and bacteria that cannot survive in an oxygen-rich environment
Black Garlic or White, They're Both Good
Whether you choose to go raw or adventure into the black, you can’t go wrong with garlic. It gives new meaning to the term “heart healthy food”! And garlic goes with just about everything. You can smother your roasting chicken with it, sauté it with veggies, add it to your salad dressing, or run it right through your juicer along with the other veggies for a real immune-booster. Whatever form of garlic you prefer, you can have some fun experimenting as you widen your culinary repertoire, and build your health at the same time!