What Is It?

Garlic has its origins in antiquity, and is one of the most widely known vegetables and seasonings, as well as one of the earliest known plants for maintenance of health and treatment of disease. Garlic is a member of the allium family, which includes onions, leeks, chives, scallions and shallots. Of these, garlic unquestionably possesses the most pungent flavor and aroma.

Garlic originated someplace in Central Asia, and was initially proliferated by nomadic tribes. Garlic was readily embraced as a food and medicine, and subsequently spread throughout the world. This proliferation is ample testimony to garlic’s popularity and appeal. Garlic not only appears in cookbooks and gardening guides, but also in literature where it has been described as both a vampire repellent and a love potion.

Garlic is also an important dietary supplement. Garlic appears in tablets and capsules, and in fluid extracts. Today Garlic is one of the best-selling botanical remedies in the United states and Europe.^1,2,3,4

Medicinal History

Traditionally, garlic is one of the most widely employed and versatile of natural remedies. As a folk remedy, garlic has been used to prevent infection, to treat colds, flu, whooping cough, bronchitis, dysentery and gastroenteritis, and to expel worms. Externally garlic has been used for all manner of skin problems, including acne and fungal infections.^3,4,5

Garlic was important to the diets of early Egyptians. The labor force which built the pyramids was given ample amounts of garlic to keep them healthy.⁶ The 1922 excavation of King Tutankhamen’s 1500 BC tomb revealed garlic cloves.^7,8 The Egyptian Codex Ebers prescribed garlic for abnormal growths, circulatory ailments, general malaise, and parasites.^9,10

The excavation of the 1400-1800 BC Greek palace of Knossos in Crete revealed garlic.⁶ Garlic also made its first appearance as a performance-enhancing supplement when it was fed to early Olympians prior to competition.^7,10 The father of medicine, Hippocrates, advocated garlic for pulmonary complaints, cleansing, and for healing abdominal growths.⁶ Greek physician Dioscorides recommended that garlic “cleans the arteries.”^9,11 Other Greeks recommended garlic for the treatment of gastrointestinal diseases, joint diseases, seizures, and animal bites.

In Chinese medicine, garlic was prescribed for respiratory and digestive disorders, and to expel worms and parasites.¹² Garlic was also used to treat fatigue, headache and insomnia, and to improve male sexual potency.⁸

In India, the foundation text of Ayurvedic medicine, the Charaka Samhita, recommends garlic as a treatment for heart disease and arthritis.¹²

In the Medieval Europe, garlic was used to relieve constipation and to prevent heat stroke.^6,8 The 12th century physician Hildegard von Bingen recommended garlic extensively, and concluded that its was more potent raw than cooked.^8,9

The 16th century Italian physician Pietro Mattioli of Sienna prescribed garlic for digestive disorders, worms and kidney disease, and for mothers during difficult childbirth. In England, garlic was employed for constipation, toothache, animal bites, the plague, and to improve cardiovascular health.⁶

In America, garlic was embraced after its introduction by French and Portugese sailors. John Gunn’s 1878 The Home Book Of Health, recommends garlic as a general tonic, to treat infections, and for asthma and other respiratory ailments.⁶

It is fair to say that in virtually every culture into which garlic has been introduced, the pungent cloves have found their way into traditional folk medicine for a wide range of health needs.

Habitat & Cultivation

This essential ingredient in Indian, Chinese, Middle Eastern, Meditteranean, Mexican and South American cuisine is widely cultivated throughout the world. The small, herbacious garlic plant grows just about any place you can plant a garden, and can be found from northern parts of Russia to the south of Australia. Garlic produces a “head,” which contains several “cloves,” which are the parts used. Garlic is cultivated on a large commercial scale in the US, India, China, Europe, The Middle East, and Central and South Americas. The plant is fairly hardy, and can tolerate diverse growing conditions.^1,3,4,5

How It Works

Garlic contains a large number of compounds. But to date allicin primarily has demonstrated significant activity at normal levels of consumption. Allicin is antimicrobial, lowers cholesterol, reduces clotting, and shows significant antioxidant protective capacity.¹³ Garlic also demonstrates insecticidal, antifungal, and antitumor properties.³ Garlic also contains an anti-clotting agent known as ajoene.¹⁴

Human clinical studies show that garlic relieves abdominal distress, belching, flatulence, colic and nausea. Garlic lowers high blood pressure, reduces blood lipids, decreases cholesterol specifically, reduces clotting, and reduces the accumulation of platelet cells on blood vessel walls.¹⁵

Contemporary Uses Approved by Authoritative Bodies

Germany’s Commission E

• Supportive to dietary measures at elevated levels of lipids in blood.
• Preventive measures for age-dependent vascular changes.

WHO

• As an adjuvant to dietetic management in the treatment of hyperlipidemia,
• And, in the prevention of atherosclerotic (age dependent) vascular changes.
• May be useful in the treatment of mild hypertension.

ESCOP

• Prophylaxis of atherosclerosis.
• Treatment of elevated blood lipids insufficiently influenced by diet.
• Improvement of the circulation in peripheral arterial vascular disease.
• Upper respiratory tract infections and catarrhal conditions

THE ABOVE TRANSLATED INTO PLAIN ENGLISH: Both Germany’s Commission E and WHO recognize the use of garlic to help reduce lipids (fats) in the blood, including cholesterol. Both also recognize the valuable role that garlic may play in reducing the risk of atherosclerosis, or hardening of the arteries. ESCOP additionally recognizes the benefits of garlic for treating upper respiratory tract infections and congestion.^13,15,16,17

Potential Risks

The following information is derived from the World Health Organization, Germany’s Commission E, ESCOP, and the AHPA Botanical Safety Handbook.

Safety issues and concerns

• Herbal Medicine cautions that garlic’s odor may pervade breath and skin.
• ESCOP and AHPA note that in rare cases garlic may cause gastrointestinal irritation.

Contraindications – based on conditions and medication intake, etc.

• Both Germany’s Commission E and ESCOP claim there are no contraindications for garlic use.
• Herbal Medicine cautions that substantial amounts of garlic should be avoided prior to surgery, as garlic can prolong bleeding time.
• WHO warns that consumption of large amounts of garlic may increase the risk of bleeding after surgery.

Potentially harmful drug interactions

According to WHO, patients using warfarin should know that garlic supplements may increase bleeding times, and that clotting times have been reported to double among patients taking warfarin who also use garlic supplements.

Allergy precautions

• ESCOP notes that in rare cases garlic may cause allergic reactions.
• WHO states that garlic has caused occasional allergic reactions such as contact dermatitis, and asthma attacks after inhaling the powdered form.^{13,15,16,17,18}

Usage Tips

• Germany’s Commission E recommends 4 grams of fresh garlic per day, minced, or equivalent preparations.
• Herbal Medicine further elucidates those “equivalent preparations:
• Infusion: 4 grams of fresh garlic in 150 ml (5 ounces) of water.
• Fluid extract: 1:1 (1 gram of garlic to 1 ml extract), 4 ml daily.
• Tincture: 1:5 ( 1 gram of garlic to 5 ml extract), 20 ml daily.
• WHO recommends 2 – 5 grams of fresh garlic per day, or 400 mg – 1.2 grams of powdered garlic, or 2-5 mg of garlic oil, or 300-1000 mg of solid extract.
• ESCOP recommends 6 – 10 mg of allicin daily, equivalent to 1 fresh clove, or 500 mg – I gram of dried garlic powder, or other preparations.

Product Choosing/Buying Tips

• Look for garlic supplement products which give equivalences to the amounts stated above.
• Look for garlic products which specify allicin content, which will range from 1% of the material on up.
• Choose organically grown garlic, or products containing organically grown garlic, whenever possible.

Science Update

A 2001 article in the Journal of Nutrition found that numerous studies show that garlic can bring about the normalization of plasma lipids, reduce clotting, inhibit platelet aggregation, and reduce blood pressure and blood glucose.¹⁹

Another 2001 article in the Journal of Nutrition reported that ample evidence shows that garlic can block chemically induced tumors and experimentally induced tumors in skin, breasts and the colon. Garlic’s anti-cancer activity is due to its ability to block the activity of a variety of enzymes.²⁰

Yet another 2001 article in the Journal of Nutrition reported that in human and animal studies, garlic extract effectively reduced total blood cholesterol and LDL cholesterol.²¹

Yet one more 2001 article in the Journal of Nutrition concluded that garlic demonstrates a protective effect against stomach and colorectal cancers.²²

A 2001 article in the Annals of Internal medicine reported on 13 clinical studies pertaining to garlic and its effectiveness in reducing cholesterol. The article concluded that garlic demonstrates only modest cholesterol-reducing activity, and that its value for such a purpose is small compared with statin drugs.²³

Controversies

There is some controversy and confusion regarding a principle constituent in garlic, the compound allicin. Some companies (such as Wakunaga) proclaim that their garlic products are “allicin free,” and they assert that this makes them more effective, healthier products. Other companies (such as Pure Gar) vociferously defend their garlic products, proudly pointing to their guaranteed allicin values. Studies on the potential beneficial effects of garlic have used both allicin-free and allicin guaranteed garlic products. Both types of products have demonstrated positive health benefits. The compound allicin is one of many potentially beneficial substances in garlic. Consumed as a vegetable or seasoning, garlic contains plenty of allicin. There is no reason at this time to assume that there is any significant health advantage in removing allicin from garlic.

Trivia

• Garlic is Allium sativum. The term garlic derives from the Anglo-Saxon “gar-leac,” which means spear plant.¹
• According to ancient legend, garlic wards off vampires.
• Garlic has been touted as a love potion for centuries. But clearly, both partners need to consume it!
• Gilroy, California is the center of commercial garlic cultivation in the US, and home to the now famous Gilroy Garlic Festival, to which thousands of garlicophiles flock each year to consume large quantities of this heroic vegetable, and to celebrate garlic’s innumerable virtues.
• The world appears to be divided into two camps concerning garlic. One one side are the garliophiles, who love garlic and champion its numerous uses. On the other side are the garlicophobes, who find garlic a repugnant and unpleasantly odoriferous substance.

References:

1. Foster, S., Garlic 1st ed., (American Botanical Council, Austin, TX 1991)
2. Rivlin, R., “Historical perspectives on the use of garlic.” Journal of Nutrition. 2001, Vol 131: 951S-954S.
3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics, 2nd ed., (New York: John Wiley & Sons, Inc. 1996).
4. Bruneton J. Pharmacognosy, Phytochemistry, Medicinal Plants. 2nd ed., (Paris: Lavoisier Publishing 1993).
5. Bown, Deni. The Herb Society Of America Encyclopedia of Herbs & Their Uses. (1st ed., (New York: Dorling Kindersley,1995).
6. Moyers, S. Garlic in Health, History and World Cuisine. 1st ed., (Suncoast Press, St Peterburg, FL 1996): 1-36.
7. Green, O., Polydoris, N., Garlic, Cancer and Heart Disease: Review and Recommendations. 1st ed., (GN Communications, Chicago, IL 1993): 21 – 41.
8. Kahn, G., “History Of garlic”. In: Garlic, The Science and Therapeutic Application of Allium Sativum L. and Related Species. (Koch H., & Lawson, L., eds) 1st ed.,(Williams and Wilkins, New York 1996): 25 – 36.
9. Bergner, P. The Healing Power Of Garlic. 1st ed., (Prima publishing, Rocklin, CA 1996): 3-26.
10. Lawson, L., Garlic: “A review of its medicinal effects and indicated active compounds.” In: Phtytomedicines of Europe. Chemistry and Biological Activity. (Lawson, L., & Bauer, R., eds) 1st ed., (ACS Symposium Series American Chemical Society, Washington, DC 1998): 176-209.
11. Riddle, J., “The medicines of greco-Roman antiquity as a source of medicines for today.” In: Prospecting for Drugs in Ancient and Medieval European Texts: A Scientific Approach. (Holland, B., ed) 1st ed., (Harwood Academic publishers, Amsterdam 1996): 7-17.
12. Woodward, P., Garlic and Friends: The History, Growth and Use of Edible Alliums. 1st ed., (Hyland House, Melbourned. Australia 1996): 2-22.
13. Blumenthal M, Goldberg A, Brinckmann J (eds). Herbal Medicine: Expanded Commission E Monographs. 1st ed., (Newton, MA: Integrative Medicine Communications. 2000).
14. Tyler, Varro., Brady, Lynn., Robbers, James., Pharmacognosy. 9th ed., (Philadelphia, Lea & Febiger, 1988
15. World Health Organization. WHO Monographs on Selected Medicinal Plants, Vol. 1. (Geneva, Switzerland: World Health Organization. 1999).
16. Blumenthal M, Busse W, Goldberg A, Gruenwald J, Hall T, Riggins CW, Rister RS (eds.). The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. S. Klein, R.S. Rister (trans.). 1st ed., (Austin, TX: American Botanical Council. 1998).
17. European Scientific Cooperative on Phytotherapy. ESCOP Monographs on the Medicinal Uses of Plant Drugs. 1st ed., (Exeter, U.K.: ESCOP 1997).
18. McGuffin M, Hobbs C, Upton R, Goldberg A (eds.). American Herbal Products Association’s Botanical Safety Handbook. 1st ed., (Boca Raton, FL: CRC Press. 1997).
19. Rahman, K. “Historical perspective on garlic and cardiovascular disease.” Journal of Nutrition 2001, 977S-979S.
20. Milner, J., “A historical perspective on garlic and cancer.” Journal Of Nutrition. Supplement, 2001, 1027S-1031S.
21. Yeh, H., Liu, L. “Cholesterol-lowering effect of garlic extracts and organosulfur compounds: Human and animal studies.” Journal Of Nutrition. Supplement 2001,
    989S-993S.
22. Fleischauer, A.,Arab, L., “Garlic and cancer: A critical review of the epidemiologic literature.” Journal Of Nutrition. Supplement 2001, 1032S-1040S.
23. Stevinson, C., Pittler, M., Ernst, E. “Garlic for treating hypercholesterolemia.” Annals Of Internal Medicine. 2000. 133: 420-429.