|Allium sativum, known as garlic, from William Woodville, Medical Botany, 1793.|
|Allium sativum |
The irrational fear of garlic is alliumphobia.
Origin and major types "A difficulty in the identification of its wild progenitor is the sterility of the cultivars", though it is thought to be descendent from the species Allium longicuspis, which grows wild in central and southwestern Asia. Allium sativum grow in the wild in areas where it has become naturalised. The "wild garlic", "crow garlic", and "field garlic" of Britain are members of the species Allium ursinum, Allium vineale, and Allium oleraceum, respectively. In North America, Allium vineale (known as "wild garlic" or "crow garlic") and Allium canadense, known as "meadow garlic" or "wild garlic" and "wild onion", are common weeds in fields. One of the best-known "garlics", the so-called elephant garlic, is actually a wild leek (Allium ampeloprasum), and not a true garlic. Single clove garlic (also called Pearl garlic or Solo garlic) also exists, originating in the Yunnan province of China.
European garlicProtected Geographical Status in Europe; these include:
- Aglio Bianco Polesano from Veneto, Italy (PDO)
- Aglio di Voghiera from Ferrara, Emilia-Romagna, Italy (PDO)
- Ail blanc de Lomagne from Lomagne in the Gascony area of France (PGI)
- Ail de la Drôme from Drôme in France (PGI)
- Ail rose de Lautrec a rose/pink garlic from Lautrec in France (PGI)
- Ajo Morado de Las Pedroñeras a rose/pink garlic from Las Pedroñeras in Spain (PGI)
VarietiesConsumer garlic can come in many varieties, including fresh, frozen, dried, fermented (Black Garlic) and shelf stable products (in tubes or jars).
CultivationGarlic is easy to grow and can be grown year-round in mild climates. While sexual propagation of garlic is indeed possible, nearly all of the garlic in cultivation is done so asexually, by planting individual cloves in the ground. In cold climates, cloves are planted in the ground in the fall, about six weeks before the soil freezes and harvested in late spring. Garlic plants are usually very hardy, and are not attacked by many pests or diseases. Garlic plants are said to repel rabbits and moles. Two of the major pathogens that attack garlic are nematodes and white rot disease, which remain in the soil indefinitely once the ground has become infected. Garlic also can suffer from pink root, a typically nonfatal disease that stunts the roots and turns them pink or red. Garlic plants can be grown close together, leaving enough room for the bulbs to mature, and are easily grown in containers of sufficient depth. When selecting garlic for planting, it is important to pick large heads to separate cloves from. Large cloves will also improve head size, along with proper spacing in the planting bed. Garlic plants prefer to grow in a soil with a high organic material content, but it is capable of growing in a wide range of soil conditions and pH levels.
There are different types or subspecies of garlic, most notably hardneck garlic and softneck garlic. The latitude where the garlic is grown affects the choice of type as garlic can be day-length sensitive. Hardneck garlic is generally grown in cooler climates; softneck garlic is generally grown closer to the equator.
Garlic scapes are removed in order to focus all the garlic's energy into bulb growth. The scapes are sold separately for cooking.
Production trendsChina is by far the largest producer of garlic, with approximately 10.5 million tonnes (23 billion pounds) annually, accounting for over 77% of world output. India (4.1%) and South Korea (2%) follow, with Egypt and Russia(1.6%) in fourth place and the United States (where garlic is grown primarily as a cash crop in every state except for Alaska) in fifth place (1.4%). This leaves 16% of global garlic production in countries that each produce less than 2% of global output. Much of the garlic production in the United States is centered on Gilroy, California, which calls itself the "garlic capital of the world".
|Top 10 garlic producers — 11 June 2008|
|No symbol = official figure, P = official figure, F = FAO estimate, *= unofficial/semiofficial/mirror data, |
C = calculated figure, A = aggregate (may include official, semiofficial, or estimates).
Source: Food And Agricultural Organization of United Nations: Economic and Social Department: The Statistical Division
Culinary useseastern Asia, south Asia, Southeast Asia, the Middle East, northern Africa, southern Europe, and parts of South and Central America. The flavour varies in intensity and aroma with the different cooking methods. It is often paired with onion, tomato, or ginger. The parchment-like skin is much like the skin of an onion and is typically removed before using in raw or cooked form. An alternative is to cut the top off the bulb, coat the cloves by dribbling olive oil (or other oil-based seasoning) over them, and roast them in an oven. Garlic softens and can be extracted from the cloves by squeezing the (root) end of the bulb, or individually by squeezing one end of the clove. In Korea, heads of garlic are fermented at high temperature; the resulting product, called black garlic, is sweet and syrupy, and is now being sold in the United States, United Kingdom and Australia.
Garlic may be applied to breads to create a variety of classic dishes such as garlic bread, garlic toast, bruschetta, crostini and canapé.
vegetables, meats, breads and pasta.
In some cuisine, the young bulbs are pickled for 3–6 weeks in a mixture of sugar, salt, and spices. In eastern Europe, the shoots are pickled and eaten as an appetizer.
Immature scapes are tender and edible. They are also known as "garlic spears", "stems", or "tops". Scapes generally have a milder taste than the cloves. They are often used in stir frying or braised like asparagus. Garlic leaves are a popular vegetable in many parts of Asia. The leaves are cut, cleaned, and then stir-fried with eggs, meat, or vegetables.
Mixing garlic with egg yolks and olive oil produces aioli. Garlic, oil, and a chunky base produce skordalia. Blending garlic, almond, oil, and soaked bread produces ajoblanco.
Garlic powder has a different taste from fresh garlic. If used as a substitute for fresh garlic, 1/8 teaspoon of garlic powder is equivalent to one clove of garlic.
Storagegrappes. Garlic is often kept in oil to produce flavoured oil; however, the practice requires measures to be taken to prevent the garlic from spoiling. Untreated garlic kept in oil can support the growth of deadly Clostridium botulinum. Refrigeration will not assure the safety of garlic kept in oil. Peeled cloves may be stored in wine or vinegar in the refrigerator.
Commercially prepared oils are widely available, but when preparing and storing garlic-infused oil at home, there is a risk of botulism if the product is not stored properly. To reduce this risk, the oil should be refrigerated and used within one week. Manufacturers add acids and/or other chemicals to eliminate the risk of botulism in their products. Two outbreaks of botulism related to garlic stored in oil have been reported.
Commercially, garlic is stored at 0°C [32°F], in a dry, low humidity environment. Garlic will keep longer if the tops remain attached.
Historical useGarlic has been used as both food and medicine in many cultures for thousands of years, dating at least as far back as the time that the Giza pyramids were built. Garlic is still grown in Egypt, but the Syrian variety is the kind most esteemed now (see Rawlinson's Herodotus, 2.125).
Garlic is mentioned in the Bible and the Talmud. Hippocrates, Galen, Pliny the Elder, and Dioscorides all mention the use of garlic for many conditions, including parasites, respiratory problems, poor digestion, and low energy. Its use in China was first mentioned in A.D. 510.
It was consumed by ancient Greek and Roman soldiers, sailors, and rural classes (Virgil, Ecologues ii. 11), and, according to Pliny the Elder (Natural History xix. 32), by the African peasantry. Galen eulogizes it as the "rustic's theriac" (cure-all) (see F. Adams' Paulus Aegineta, p. 99), and Alexander Neckam, a writer of the 12th century (see Wright's edition of his works, p. 473, 1863), recommends it as a palliative for the heat of the sun in field labor.
In the account of Korea's establishment as a nation, gods were said to have given mortal women with bear and tiger temperaments an immortal's black garlic before mating with them.[vague] This is a genetically unique six-clove garlic that was to have given the women supernatural powers and immortality. This garlic is still cultivated in a few mountain areas today.
In his Natural History, Pliny gives an exceedingly long list of scenarios in which it was considered beneficial (N.H. xx. 23). Dr. T. Sydenham valued it as an application in confluent smallpox, and, says Cullen (Mat. Med. ii. p. 174, 1789), found some dropsies cured by it alone. Early in the 20th century, it was sometimes used in the treatment of pulmonary tuberculosis or phthisis.
English cuisine (though it is said to have been grown in England before 1548) and has been a much more common ingredient in Mediterranean Europe. Garlic was placed by the ancient Greeks on the piles of stones at crossroads, as a supper for Hecate (Theophrastus, Characters, The Superstitious Man). A similar practice of hanging garlic, lemon and red chilli at the door or in a shop to ward off potential evil, is still very common in India. According to Pliny, garlic and onions were invoked as deities by the Egyptians at the taking of oaths. (Pliny also states that garlic demagnetizes lodestones, which is not factual.) The inhabitants of Pelusium, in lower Egypt (who worshiped the onion), are said to have had an aversion to both onions and garlic as food.
To prevent the plant from running to leaf, Pliny (N.H. xix. 34) advised bending the stalk downward and covering with earth; seeding, he observes, may be prevented by twisting the stalk (by "seeding", he most likely meant the development of small, less potent bulbs).
Medicinal use and health benefits
|Nutritional value per 100 g (3.5 oz)|
|Energy||623 kJ (149 kcal)|
|Dietary fiber||2.1 g|
|- beta-carotene||5 μg (0%)|
|Thiamine (Vit. B1)||0.2 mg (15%)|
|Riboflavin (Vit. B2)||0.11 mg (7%)|
|Niacin (Vit. B3)||0.7 mg (5%)|
|Pantothenic acid (B5)||0.596 mg (12%)|
|Vitamin B6||1.235 mg (95%)|
|Folate (Vit. B9)||3 μg (1%)|
|Vitamin C||31.2 mg (52%)|
|Calcium||181 mg (18%)|
|Iron||1.7 mg (14%)|
|Magnesium||25 mg (7%)|
|Phosphorus||153 mg (22%)|
|Potassium||401 mg (9%)|
|Sodium||17 mg (1%)|
|Zinc||1.16 mg (12%)|
|Manganese 1.672 mg|
|Selenium 14.2 μg|
|Percentages are relative to US recommendations for adults. |
Source: USDA Nutrient database
Although these studies showed protective vascular changes in garlic-fed subjects, a randomized clinical trial funded by the National Institutes of Health (NIH) in the United States and published in the Archives of Internal Medicine in 2007 found that the consumption of garlic in any form did not reduce blood cholesterol levels in patients with moderately high baseline cholesterol levels.
According to the Heart.org, "despite decades of research suggesting that garlic can improve cholesterol profiles, a new NIH-funded trial found absolutely no effects of raw garlic or garlic supplements on LDL, HDL, or triglycerides... The findings underscore the hazards of meta-analyses made up of small, flawed studies and the value of rigorously studying popular herbal remedies."
In 2007, the BBC reported that Allium sativum may have other beneficial properties, such as preventing and fighting the common cold. This assertion has the backing of long tradition in herbal medicine, which has used garlic for hoarseness and coughs. The Cherokee also used it as an expectorant for coughs and croup.
Allium sativum has been found to reduce platelet aggregation and hyperlipidemia.
Garlic is also alleged to help regulate blood sugar levels. Regular and prolonged use of therapeutic amounts of aged garlic extracts lower blood homocysteine levels and has shown to prevent some complications of diabetes mellitus. People taking insulin should not consume medicinal amounts of garlic without consulting a physician.
In 1858, Louis Pasteur observed garlic's antibacterial activity, and it was used as an antiseptic to prevent gangrene during World War I and World War II. More recently, it has been found from a clinical trial that a mouthwash containing 2.5% fresh garlic shows good antimicrobial activity, although the majority of the participants reported an unpleasant taste and halitosis.
Garlic cloves are used as a remedy for infections (especially chest problems), digestive disorders, and fungal infections such as thrush.
Garlic has been found to enhance thiamin absorption and therefore reduce the likelihood for developing the thiamin deficiency beriberi.
In 1924, it was found that garlic is an effective way to prevent scurvy, due to its high vitamin C content.
Garlic has been used reasonably successfully in AIDS patients to treat cryptosporidium in an uncontrolled study in China. It has also been used by at least one AIDS patient to treat toxoplasmosis, another protozoal disease.
Garlic supplementation in rats, along with a high protein diet, has been shown to boost testosterone levels.
A 2010 double-blind, parallel, randomised, placebo-controlled trial involving 50 patients whose routine clinical records in general practice documented treated but uncontrolled hypertension. Concluded that "Our trial suggests that aged garlic extract is superior to placebo in lowering systolic blood pressure similarly to current first line medications in patients with treated but uncontrolled hypertension."
Adverse effects and toxicologyGarlic is known for causing halitosis as well as causing sweat to have a pungent 'garlicky' smell which is caused by allyl methyl sulfide (AMS). AMS is a gas which is absorbed into the blood during the metabolism of garlic; from the blood it travels to the lungs (and from there to the mouth causing bad breath) and skin where it is exuded through skin pores. Washing the skin with soap is only a partial and imperfect solution to the smell. Studies have shown that sipping milk at the same time as consuming garlic can significantly neutralize bad breath. Mixing garlic with milk in the mouth before swallowing reduced the odor better than drinking milk afterward. Plain water, mushrooms and basil may also reduce the odor; the mix of fat and water found in milk, however, was the most effective.
Raw garlic is more potent; cooking garlic reduces the effect. The green dry 'folds' in the center of the garlic clove are especially pungent. The sulfur compound allicin, produced by crushing or chewing fresh garlic produces other sulfur compounds: ajoene, allyl sulfides, and vinyldithiins. Aged garlic lacks allicin, but may have some activity due to the presence of S-allylcysteine.
In a rat study, allicin, was found to be an activator of TRPA1. The neurons released neurotransmitters in the spinal cord to generate pain signals and released neuropeptides at the site of sensory nerve activation, resulting in vasodilation as well as inflammation. Allicin is released only by cruching or chewing raw garlic and cannot be formed from cooked garlic. This explains short term back pain when garlic is eaten raw.
Some people suffer from allergies to garlic and other plants in the allium family. Symptoms can include irritable bowel, diarrhea, mouth and throat ulcerations, nausea, breathing difficulties, and in rare cases anaphylaxis. Garlic-sensitive patients show positive tests to diallyl disulfide, allylpropyldisulfide, allylmercaptan and allicin, all of which are present in garlic. People who suffer from garlic allergies will often be sensitive to many plants in the lily family (Liliaceae), including onions, garlic, chives, leeks, shallots, garden lilies, ginger, and bananas.
Garlic can also cause indigestion, nausea, vomiting, and diarrhea. It thins the blood (as does aspirin); this had caused very high quantities of garlic and garlic supplements to be linked with an increased risk of bleeding, particularly during pregnancy and after surgery and childbirth, although culinary quantities are safe for consumption. There have been several reports of serious burns resulting from garlic being applied topically for various purposes, including naturopathic uses and acne treatment, so care must be taken to test a small area of skin using a very low concentration of garlic. On the basis of numerous reports of such burns, including burns to children, topical use of raw garlic, as well as insertion of raw garlic into body cavities, is discouraged. In particular, topical application of raw garlic to young children is not advisable. The side effects of long-term garlic supplementation, if any exist, are largely unknown, and no FDA-approved study has been performed. However, garlic has been consumed for several thousand years without any adverse long-term effects, suggesting that modest quantities of garlic pose, at worst, minimal risks to normal individuals. Possible side effects include gastrointestinal discomfort, sweating, dizziness, allergic reactions, bleeding, and menstrual irregularities. The safety of garlic supplements had not been determined for children.; some breastfeeding mothers have found their babies slow to feed and have noted a garlic odour coming from their baby when they have consumed garlic.
Garlic may interact with warfarin, antiplatelets, saquinavir, antihypertensives, calcium channel blockers, and hypoglycemic drugs, as well as other medications. Members of the alium family might be toxic to cats or dogs. Some degree of liver toxicity has been demonstrated in rats, particularly in extremely large quantities exceeding those that a rat would consume under normal situations.
PropertiesWhen crushed, Allium sativum yields allicin, an antibiotic and antifungal compound (phytoncide). It has been claimed that it can be used as a home remedy to help speed recovery from strep throat or other minor ailments because of its antibiotic properties. It also contains the sulfur containing compounds alliin, ajoene, diallylsulfide, dithiin, S-allylcysteine, and enzymes, vitamin B, proteins, minerals, saponins, flavonoids, and maillard reaction products, which are non-sulfur containing compounds. Furthermore a phytoalexin called allixin was found, a non-sulfur compound with a γ-pyrone skeleton structure with anti-oxidative effects, anti-microbial effects, anti-tumor promoting effects, inhibition of aflatoxin B2 DNA binding, and neurotrophic effects. Allixin showed an anti-tumor promoting effect in vivo, inhibiting skin tumor formation by TPA and DMBA initiated mice. Analogs of this compound have exhibited anti tumor promoting effects in in vitro experimental conditions. Herein, allixin and/or its analogs may be expected useful compounds for cancer prevention or chemotherapy agents for other diseases.
The composition of the bulbs is approximately 84.09% water, 13.38% organic matter, and 1.53% inorganic matter, while the leaves are 87.14% water, 11.27% organic matter, and 1.59% inorganic matter.
The phytochemicals responsible for the sharp flavor of garlic are produced when the plant's cells are damaged. When a cell is broken by chopping, chewing, or crushing, enzymes stored in cell vacuoles trigger the breakdown of several sulfur-containing compounds stored in the cell fluids. The resultant compounds are responsible for the sharp or hot taste and strong smell of garlic. Some of the compounds are unstable and continue to evolve over time. Among the members of the onion family, garlic has by far the highest concentrations of initial reaction products, making garlic much more potent than onions, shallots, or leeks. Although many humans enjoy the taste of garlic, these compounds are believed to have evolved as a defensive mechanism, deterring animals like birds, insects, and worms from eating the plant.
A large number of sulfur compounds contribute to the smell and taste of garlic. Diallyl disulfide is believed to be an important odor component. Allicin has been found to be the compound most responsible for the "hot" sensation of raw garlic. This chemical opens thermoTRP (transient receptor potential) channels that are responsible for the burning sense of heat in foods. The process of cooking garlic removes allicin, thus mellowing its spiciness.
Due to its strong odor, garlic is sometimes called the "stinking rose". When eaten in quantity, garlic may be strongly evident in the diner's sweat and breath the following day. This is because garlic's strong-smelling sulfur compounds are metabolized, forming allyl methyl sulfide. Allyl methyl sulfide (AMS) cannot be digested and is passed into the blood. It is carried to the lungs and the skin, where it is excreted. Since digestion takes several hours, and release of AMS several hours more, the effect of eating garlic may be present for a long time.
This well-known phenomenon of "garlic breath" is alleged to be alleviated by eating fresh parsley. The herb is, therefore, included in many garlic recipes, such as pistou, persillade, and the garlic butter spread used in garlic bread. However, since the odour results mainly from digestive processes placing compounds such as AMS in the blood, and AMS is then released through the lungs over the course of many hours, eating parsley provides only a temporary masking. One way of accelerating the release of AMS from the body is the use of a sauna.
Because of the AMS in the bloodstream, it is believed by some to act as a mosquito repellent. However, there is no evidence to suggest that garlic is actually effective for this purpose.
Spiritual and religious perceptionsGarlic has been regarded as a force for both good and evil. According to Cassell's Dictionary of Superstitions, there is an Islamic myth that considers that after Satan left the Garden of Eden, garlic arose in his left footprint and onion in the right. In Europe, many cultures have used garlic for protection or white magic, perhaps owing to its reputation as a potent preventative medicine. Central European folk beliefs considered garlic a powerful ward against demons, werewolves, and vampires. To ward off vampires, garlic could be worn, hung in windows, or rubbed on chimneys and keyholes.
In both Hinduism and Jainism, garlic is considered to stimulate and warm the body and to increase one's desires. Some devout Hindus generally avoid using garlic and the related onion in the preparation of foods for religious festivities and events. Followers of the Jain religion avoid eating garlic and onion on a daily basis.
In connection with the odor associated with garlic, Islam views eating garlic and subsequently going to the mosque as inappropriate because the smell from the mouth will irritate the fellow worshippers.