Latin name: Allium sativum
Source material: Garlic powder
Family: Alliaceae (Liliaceae)
Common names: Garlic, Cultivated garlic, Poor Man's treacle
Garlic is a small, very pungent Onion-like plant. It has been used for millennia (it was mentioned in 1550 BC) as a flavouring and a medicine, and is now important in many cuisines worldwide. In some parts of the world, Garlic’s use also has religious connotations.
Only a few members of this family are important as food plants, notably Onion, Garlic, Chive, Leek, and Rakkyo. Garlic’s edible bulb or “head” grows beneath the ground. This bulb is made up of sections called cloves, each encased in its own parchment-like membrane. Today’s major Garlic suppliers include the United States (mainly California, Texas and Louisiana), France, Spain, Italy and Mexico. There are several major types of Garlic available, with cloves up to 6 cm in diameter. The flavours, in addition to being characteristic, are complex, as they are derived enzymatically from a number of involatile precursors. Fresh Garlic is available year-round.
Garlic grows in cultivated beds, with occasional escapes. Garlic bulbs are eaten, either raw or cooked, as flavouring.. They are usually peeled before use in recipes. Crushing, chopping, pressing or pureeing Garlic releases more of its essential oils and provides a sharper, more assertive flavour than slicing or leaving it whole. Garlic is readily available in forms other than fresh, such as dehydrated flakes or powder. Garlic salt is Garlic powder blended with salt and a moisture-absorbing agent. Garlic extract and Garlic juice are derived from pressed Garlic cloves. One unfortunate side-effect of Garlic is that, because its essential oils permeate the lung tissue, it remains with the body long after it has been consumed, affecting breath and even skin odour. The stems, leaves, flowers and seed can be eaten raw or cooked, and are rather milder than the bulbs.
Garlic can reduce nasal congestion and lower blood pressure and blood cholesterol (for example, demographic studies suggest that Garlic is responsible for the low incidence of arteriosclerosis in areas of Italy and Spain where consumption of the bulb is heavy). It has been employed as an antiviral, antibacterial, fungicidal, vermifuge, vasodilator, expectorant, diuretic, antiasthmatic, antispasmodic, febrifuge, stomachic, skin-soothing, tonic, and immunostimulant agent. It may, however, induce migraines. Garlic extract inhibits chromosomal breaks due to sodium arsenite (arsenic), a contaminant in ground water. It has been shown that Garlic aids detoxification of chronic lead poisoning. It is also said to have anticancer activity. Recent research has indicated that Garlic reduces glucose metabolism in diabetics.
The growing plant is said to repel insects, rabbits and moles. An extract of the plant can be used as an insect repellent.
Cloves of Garlic are sometimes spread among stored fruit to delay rotting. The juice is also used as glue for mending glass and china.
No allergens from this plant have yet been characterised.
Using serum from a Garlic-allergic individual, a 12 kDa protein band to young Garlic, mature Garlic, Onion, and Leek extracts was detected. Similar bands could also be detected with Mugwort pollen and Hazelnut extract (1).
Protein bands of 10, 20 and 40 kDa were detected in a patient with urticaria who was affected by cooked and raw Onions. Garlic appears to have heat-stabile and heat-labile allergens (2).
A 12 kDa and a 40-50 kDa protein have been detected (3), probably corresponding to a mannose-binding lectin (4) and alliinase (5) respectively, both previously reported and probably heat-labile.
In a patient with nasal symptoms following exposure to Garlic dust, significant protein bands at 14 and 40 kDa to Garlic extract were demonstrated (6).
In a study of 15 patients with Garlic allergy, with symptoms of rhinitis, urticaria, dermatitis, and asthma, IgE-binding components ranging from 31 to 60 kDa were isolated. A component with a molecular weight of approximately 56 kDa was detected by all 15 sera and identified as alliin lyase. Other IgE-binding components of various molecular weights were detected at frequencies of less than 30%; for example, 4 serum samples gave a positive reaction to a 42 kDa component. Periodate oxidation showed that carbohydrate groups were involved in the substance’s antigenicity, allergenicity, and cross-reactivity (7).
An extensive cross-reactivity among the different individual species of the genus could be expected, as well as to a certain degree among members of the family Alliaceae (previously categorised as Liliaceae), such as Onion, Leek, Garlic, Asparagus and Chives (8-9).
The major Garlic allergen, alliin lyase, showed strong cross-reactivity with alliin lyases from other Allium species, namely Leek, shallot, and Onion (7).
Cross-allergenicity between Garlic and other members of the Liliaceae family was documented through the RAST inhibition technique (10).
The presence of structurally similar allergens in Garlic, Onion, and certain pollens of Phleum and Chenopodium has been described. There was partial abolishment of the IgE binding to several of these allergens (11). The clinical significance of this is not yet known.
Garlic can induce symptoms of food allergy in sensitised individuals (12-13). Garlic is well-known cause of contact dermatitis and asthma. However, it is thought to be an uncommon cause of food or other allergy in children (1-2,14-16). In a European study of 589 individuals with food allergy, SPT positivity to Liliaceae (Garlic, Onion, Chive) was documented in 4.6% of children and 7.7% of adults (17).
In an evaluation of 163 asthmatic French children with food allergy who were assessed for food-induced asthma using DBPCFC, the most frequent offending foods were, sometimes in association, Peanut (30.6%), Hen’s egg (23.1%), Cow’s milk (9.3%), Mustard (6.9%), Codfish (6%), Shrimp (4.5%), Kiwi fruit (3.6%), Hazelnut (2.7%), Cashew nut (2.1%), Almond (1.5%), and Garlic (1.2%) (18). A subsequent study was done by the same main author of a cross-sectional, descriptive, questionnaire-based survey conducted in Toulouse schools in France to determine the prevalence of food allergies among schoolchildren; it was reported that, out of 2,716 respondents, 192 self-reported a food allergy, but that there was only a single reported case of allergy to Garlic (19).
A study was conducted at 17 clinics in 15 European cities to evaluate the differences among some northern countries regarding what foods, according to food-allergic patients, elicit hypersensitivity symptoms. It was reported, after evaluation of questionnaires concerning 86 different foods, that the foods apparently most often eliciting symptoms in Russia, Estonia, and Lithuania were citrus fruits, chocolate, honey, Apple, Hazelnut, Strawberry, fish, Tomato, Hen’s egg, and Milk; these results differed from those of Sweden and Denmark, where Birch pollen-related foods, such as nuts, Apple, Pear, Kiwi, stone fruits, and Carrot, were the most common reported causes. The most common symptoms reported were oral allergy syndrome and urticaria. Birch pollen-related foods apparently dominated as allergens in Scandinavia, whereas some Mugwort-related foods seemed to be of more importance in Russia and the Baltic States. Among 1,139 individuals, Garlic was the 57th most reported food allergen, resulting in adverse effects in 8.2% (20).
In an Indian study of 24 children aged 3 to 15 who had documented deterioration in control of their perennial asthma, IgE antibodies to Garlic were documented in 14 (58%) (21).
A large population-based study of adverse reactions to food in adults in Istanbul found Garlic to be an uncommon self-reported cause of adverse reactions (22).
A study described a small population of patients in the mid-southern region of Taiwan who were allergic to Garlic. Symptoms included rhinitis, urticaria, dermatitis, and asthma. All the patients had lived near Garlic fields, worked or played near a Garlic store, and eaten Garlic over a long period of time. Serum samples were obtained from all 15 patients, and the allergen alliin lyase was identified in all. All 12 patients were positive on intradermal testing with purified Garlic alliin lyase, whereas 58% were positive with a lower concentration (7).
A 16-month-old boy with a history of Cow’s milk and Hen’s egg white allergy has been reported as developing urticaria on the face and neck immediately after contact with fresh Garlic. He tolerated cooked Garlic (3).
Garlic may result in anaphylactic reactions, as described in a 23-year-old woman who had eaten young Garlic (1).
Occupational asthma and rhinitis have been reported, which may have an onset long after work with the substance (11,23-24). Occupational allergy to Garlic dust has also been reported (25-26). In an atopic patient, repeated exposure to Garlic dust induced severe asthma. The patient subsequently also developed marked adverse responses after ingesting Garlic. A skin prick test and a bronchial challenge test with Garlic dust and extract were both positive, as was an oral challenge test with Garlic dust. Serum Garlic-specific IgE was unusually high (10).
A study reported on a patient who presented with nasal symptoms when working with spices that included Garlic and Onion dust. Skin prick tests were positive for Onion, Garlic powder and fresh Liliacea (not specified). IgE antibody levels were found to Garlic and Onion, and significant protein bands at 14 and 40 kDa with Garlic extract were demonstrated. Nasal challenge showed an increase in inspiratory nasal resistance that was higher than 100% of the basal value for both Onion extract and Garlic (6).
Allergic contact dermatitis to Garlic has a typical clinical presentation, but this is often masked if the reaction presents concurrently with another form of hand dermatitis or other conditions (27-29). Reactions may be immediate or delayed (30). Occupational airborne allergic contact dermatitis from Garlic has been reported (31).
Allergic contact cheilitis to Garlic has been described (32).
The spectrum of Garlic-related skin adverse reactions comprises irritant contact dermatitis (with the rare variant of zosteriform dermatitis), pemphigus, contact urticaria, protein contact dermatitis, and allergic contact dermatitis, as well as combinations of these (33-34).
Garlic is a common cause of contact dermatitis, in particular in an occupational environment (35-39). Contact dermatitis from Garlic is usually due to handling of Garlic for cooking, especially in the cases of greengrocers, housewives and cooks (40-43). In India, Garlic was reported to be the offending agent in 6.7% of patients seen with contact dermatitis (44). Occupational contact dermatitis from a Garlic and herb mixture has been described (45). Garlic-induced systemic contact dermatitis has also been reported (46). Garlic-sensitive patients showed positive tests to diallyldisulfide, allylpropyldisulfide, allylmercaptan and allicin, all present in Garlic (47).
Patients have experienced second-degree burns of the forehead, breast, and other parts of the body, induced by topical application of crushed Garlic (48-50). These burns may mimic herpes zoster (51). Children have also been adversely affected by poultices containing Garlic (52).
A case of superficial pemphigus has been reported as appearing spontaneously in a 49-year-old man and running a course that proved to be affected by dietary factors, in particular by the consumption of Garlic (53).
Compiled by Dr Harris Steinman, firstname.lastname@example.org
- Perez-Pimiento AJ, Moneo I, Santaolalla M, de Paz S, Fernandez-Parra B, Dominguez-Lazaro AR. Anaphylactic reaction to young garlic. Allergy 1999;54(6):626-9
- Asero R, Mistrello G, Roncarolo D, Antoniotti PL, Falagiani P. A case of garlic allergy.
J Allergy Clin Immunol 1998;101(3):427-8
- Pires G, Pargana E, Loureiro V, Almeida MM, Pinto JR. Allergy to garlic.
- Smeets K, Van Damme EJ, Verhaert P, Barre A, Rouge P, Van Leuven F, Peumans WJ. Isolation, characterization and molecular cloning of the mannose-binding lectins from leaves and roots of garlic (Allium sativum L.).
Plant Mol Biol 1997;33(2):223-34
- Rabinkov A, Zhu XZ, Grafi G, Galili G,
Mirelman D. Alliin lyase (Alliinase) from garlic (Allium sativum). Biochemical characterization and cDNA cloning.
Appl Biochem Biotechnol 1994;48(3):149-71
- Jimenez-Timon A, Rodriguez Trabado A, Hernandez Arbeiza FJ, Porcel Carreno S, Rodriguez Martin E, Agustin Herrero J, Cobo Lopez R. Anterior rhinomanometry as a diagnostic test in occupational allergy caused by Liliaceae. [Spanish] Allergol Immunopathol (Madr) 2002;30(5):295-9
- Kao SH, Hsu CH, Su SN, Hor WT, Chang T WH,
Chow LP. Identification and immunologic characterization of an allergen, alliin lyase, from garlic (Allium sativum).
J Allergy Clin Immunol 2004;113(1):161-8
- Yman L. Botanical relations and immunological cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
- Sanchez-Hernandez MC, Hernandez M, Delgado J, Guardia P, Monteseirin J, Bartolome B, Palacios R, Martinez J, Conde J. Allergenic cross-reactivity in the Liliaceae family. Allergy 2000;55(3):297-9
- Lybarger JA, Gallagher JS, Pulver DW, Litwin A, Brooks S, Bernstein IL. Occupational asthma induced by inhalation and ingestion of garlic.
J Allergy Clin Immunol 1982;69(5):448-54
- Anibarro B, Fontela JL, De-La-Hoz F. Occupational asthma induced by garlic dust. J Allergy Clin Immunol 1997;100(6 Pt 1):734-8
- Bandelier C, Leimgruber A, Wassenberg J, Bart PA, Spertini F. Rare food allergies. [French]
Rev Med Suisse 2008;4(154):1024-6, 1028-9
- Zuidmeer L, Goldhahn K, Rona RJ, Gislason D, Madsen C, Summers C, Sodergren E, Dahlström J, Lindner T, Sigurdardottir ST, McBride D, Keil T. The prevalence of plant food allergies: a systematic review.
J Allergy Clin Immunol 2008;121(5):1210-8
- Rance F, Dutau G. Labial food challenge in children with food allergy.
Pediatr Allergy Immunol 1997;8(1):41-4
- Nowak-Wegrzyn A, Conover-Walker MK, Wood RA.
Food-allergic reactions in schools and preschools.
Arch Pediatr Adolesc Med 2001;155(7):790-5
- Moneret-Vautrin DA, Kanny G. Food-induced anaphylaxis. A new French multicenter survey [French]. Ann Gastroenterol Hepatol (Paris) 1995;31(4):256-63
- Moneret-Vautrin DA, Morisset M, Lemerdy P,
Croizier A, Kanny G. Food allergy and IgE sensitization caused by spices: CICBAA data (based on 589 cases of food allergy).
Allerg Immunol (Paris) 2002;34(4):135-40
- Rance F, Dutau G. Asthma and food allergy: report of 163 pediatric cases. [French] Arch Pediatr 2002;9 Suppl 3:402s-407s
- Rance F, Grandmottet X, Grandjean H. Prevalence and main characteristics of schoolchildren diagnosed with food allergies in France. Clin Exp Allergy 2005;35(2):167-72
- Eriksson NE, Moller C, Werner S, Magnusson J, Bengtsson U, Zolubas M. Self-reported food hypersensitivity in Sweden, Denmark, Estonia, Lithuania, and Russia. J Investig Allergol Clin Immunol 2004;14(1):70-9
- Agarkhedkar SR, Bapat HB, Bapat BN. Avoidance of food allergens in childhood asthma. Indian Pediatr 2005;42(4):362-6
- Gelincik A, Büyüköztürk S, Gül H, Işik E, Işsever H, Ozşeker F, Colakoğlu B, Dal M, Ayvaz O, Güngör G, Akkor A. Confirmed prevalence of food allergy and non-allergic food hypersensitivity in a Mediterranean population. Clin Exp Allergy 2008;38(8):1333-41
- Seuri M, Taivanen A, Ruoppi P, Tukiainen H.
Three cases of occupational asthma and rhinitis caused by garlic.
Clin Exp Allergy 1993;23(12):1011-4
- Lemiere C, Cartier A, Lehrer SB, Malo JL. Occupational asthma caused by aromatic herbs. Allergy 1996;51(9):647-9
- Couturier P, Bousquet J. Occupational allergy secondary inhalation of garlic dust.
J Allergy Clin Immunol 1982;70(2):145
- Falleroni AE, Zeiss CR, Levitz D. Occupational asthma secondary to inhalation of garlic dust.
J Allergy Clin Immunol 1981;68(2):156-60
- Delaney TA, Donnelly AM. Garlic dermatitis. Australas J Dermatol 1996;37(2):109-10
- McFadden JP, White IR, Rycroft RJ. Allergic contact dermatitis from garlic.
Contact Dermatitis 1992;27(5):333-4
- McFadden JP, White JM, Basketter DA, Kimber I.
Reduced allergy rates in atopic eczema to contact allergens used in both skin products and foods: atopy and the ’hapten-atopy hypothesis’.
Contact Dermatitis 2008;58(3):156-8
- Campolmi P, Lombardi P, Lotti T, Sertoli A. Immediate and delayed sensitization to garlic. Contact Dermatitis 1982;8(5):352-3
- Bassioukas K, Orton D, Cerio R. Occupational airborne allergic contact dermatitis from garlic with concurrent Type I allergy.
Contact Dermatitis 2004;50(1):39-41
- Ekeowa-Anderson AL, Shergill B, Goldsmith P.
Allergic contact cheilitis to garlic.
Contact Dermatitis 2007;56(3):174-5
- Jappe U, Bonnekoh B, Hausen BM, Gollnick H.
Garlic-related dermatoses: case report and review of the literature.
Am J Contact Dermat 1999;10(1):37-9
- Fernandez de Corres L, Leanizbarrutia I, Munoz D, Corrales JL. Allergic contact dermatitis caused by garlic, Primula, Frullania and Compositae. [Spanish] Allergol Immunopathol (Madr) 1985;13(4):291-9
- Kanerva L, Estlander T, Jolanki R. Occupational allergic contact dermatitis from spices.
Contact Dermatitis 1996;35(3):157-62
- Lembo G, Balato N, Patruno C, Auricchio L, Ayala F. Allergic contact dermatitis due to garlic (Allium sativum).
Contact Dermatitis 1991;25(5):330-1
- Montalti M, Lucadei P, Fioriti M, Luchetti E, Sanchez MA, Filippousi M, Cupelli V, Arcangeli G.
Work related sensitization risk in hotel school students, the role of garlic. [Italian] G Ital Med Lav Ergon 2007;29(3 Suppl):855-7
- Hubbard VG, Goldsmith P. Garlic-fingered chefs. Contact Dermatitis 2005;52(3):3-166
- Cronin E. Dermatitis of the hands in caterers. Contact Dermatitis 1987;17(5):265-9
- Lautier R, Wendt V. Contact allergy to Alliaceae. Case report and literature review. [German] Derm Beruf Umwelt 1985;33(6):213-5
- Martinescu E. Contact dermatitis caused by Allium sativum. [Romanian] Rev Med Chir Soc Med Nat Iasi 1981;85(3):541-2
- Mitchell JC. Contact sensitivity to garlic (Allium). Contact Dermatitis 1980;6(5):356-7
- van Ketel WG, de Haan P. Occupational eczema from garlic and onion.
Contact Dermatitis 1978;4(1):53-4
- Singhal V, Reddy BS. Common contact sensitizers in Delhi.
J Dermatol 2000;27(7):440-5
- Hughes TM, Varma S, Stone NM. Occupational contact dermatitis from a garlic and herb mixture. Contact Dermatitis 2002;47(1):48
- Burden AD, Wilkinson SM, Beck MH, Chalmers RJ. Garlic-induced systemic contact dermatitis.
Contact Dermatitis 1994;30(5):299-300
- Papageorgiou C, Corbet JP, Menezes-Brandao F, Pecegueiro M, Benezra C. Allergic contact dermatitis to garlic (Allium sativum L.). Identification of the allergens.
Arch Dermatol Res 1983;275(4):229-34
- Baruchin AM, Sagi A, Yoffe B, Ronen M. Garlic burns. Burns 2001;27(7):781-2
- Hviid K, Alsbjorn B. ”Burns” caused by local application of garlic. [Danish] Ugeskr Laeger 2000;162(50):6853-4
- Roberge RJ, Leckey R, Spence R, Krenzelok EJ.
Garlic burns of the breast.
Am J Emerg Med 1997;15(5):548
- Farrell AM, Staughton RC. Garlic burns mimicking herpes zoster.
Lancet 1996 27;347(9009):1195
- Parish RA, McIntire S, Heimbach DM. Garlic burns: a naturopathic remedy gone awry. Pediatr Emerg Care 1987;3(4):258-60
- Ruocco V, Brenner S, Lombardi ML. A case of diet-related pemphigus.