Garlic has been used for centuries as a culinary spice and medicinal herb. Garlic has been cultivated in the Middle East for more than 5,000 years and has been an important part of Traditional Chinese Medicine. The region with the largest commercial garlic production is central California. China is also a supplier of commercial garlic. The bulb is used medicinally.
How It Works
The sulfur compound allicin, produced by crushing or chewing fresh garlic or by taking powdered garlic products with allicin potential, in turn produces other sulfur compounds: ajoene, allyl sulfides, and vinyldithiins. Aged garlic products lack allicin, but may have activity due to the presence of S-allylcysteine.
Many publications have shown that garlic supports the cardiovascular system. While earlier trials suggest it may mildly lower cholesterol and triglyceride levels in the blood, more recent trials found garlic to have minimal success in lowering cholesterol and triglycerides. Garlic also inhibits platelet stickiness (aggregation) and increases fibrinolysis, which results in a slowing of blood coagulation. It is mildly antihypertensive and has antioxidant activity.
Garlic’s cardiovascular protective effects were illustrated in a four-year clinical trial on people 50-80 years old with atherosclerosis. It was found that consumption of 900 mg of a standardized garlic supplement reduced arterial plaque formation by 5-18%. The benefits were most notable in women.
In test tube studies garlic has been found to have antibacterial, antiviral, and antifungal activity.
Human population studies suggest that eating garlic regularly reduces the risk of esophageal, stomach, and colon cancer. This may be partly due to garlic’s ability to reduce the formation of carcinogenic compounds.
- Atherosclerosis: hardening of the arteries
- Hypertension: high blood pressure
- Benign Prostatic Hyperplasia: prostate size
- Common Cold
- Sore Throat
- High Cholesterol
- Athlete’s Foot: crushed garlic, applied topically
- Candidiasis: yeast infection, thrush, fungus
- Ear Infections
- Peptic Ulcer
- Sickle Cell Anemia: aged garlic extract showed significant improvement and less painful crises when taken with folic acid, vitamin C, and vitamin E
Uses in Ancient Scripture
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. Louis Pasteur studied the antibacterial action of garlic in 1858.
Some studies have indicated that babies of breast-feeding mothers, who consume higher than average amounts of garlic or use it as a supplement, have developed colic.
Resources and Studies to Dive Into
Berthold HK, Sudhop T, von Bergmann K. Effect of a garlic oil preparation on serum lipoproteins and cholesterol metabolism. JAMA 1998;279:1900-2.
Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 134.
Brown DJ. Herbal Prescriptions for Better Health. Rocklin, CA: Prima Publishing, 1996, 97-109.
Dorant E, van der Brandt PA, et al. Garlic and its significance for the prevention of cancer in humans: A critical view. Br J Cancer 1993;67:424-9 [review].
Fleishauer AT, Poole C, Arab L. Garlic consumption and cancer prevention: meta-analyses of colorectal and stomach cancers. Am J Clin Nutr 2000;72:1047-52.
Hughes BG, Lawson LD. Antimicrobial effects of Allium sativum L. (garlic), Allium ampeloprasum L. (elephant garlic) and Allium cepa L. (onion), garlic compounds and commercial garlic supplement products. Phytother Res 1991;5:154-8.
Isaacsohn JL, Moser M, Stein EA, et al. Garlic powder and plasma lipids and lipoproteins. Arch Intern Med 1998;158:1189-94.
Kleijnen J, Knipschild P, Ter Riet G. Garlic, onion and cardiovascular risk factors: A review of the evidence from human experiments with emphasis on commercially available preparations. Br J Clin Pharmacol 1989;28:535-44.
Koch HP, Lawson LD (eds). Garlic: The Science and Therapeutic Application of Allium sativaum L and Related Species, 2d ed. Baltimore: Williams and Wilkins, 1996, 62-4.
Koscielny J, Klüendorf D, Latza R, et al. The antiatherosclerotic effect of Allium sativum. Atherosclerosis 1999;144:237-49.
Legnani C, Frascaro M, Guazzaloca G, et al. Effects of a dried garlic preparation on fibrinolysis and platelet aggregation in healthy subjects. Arzneim-Forsch Drug Res 1993;43:119-22.
McCrindle BW, Helden E, Conner WT. Garlic extract therapy in children with hypercholesterolemia. Arch Pediatr Adolesc Med 1998;152:1089-94.
Neil HA, Silagy CA, Lancaster T, et al. Garlic powder in the treatment of moderate hyperlipidaemia: A controlled trial and a meta-analysis. J R Coll Phys 1996;30:329-34.
Silagy C, Neil A. Garlic as a lipid-lowering agent-a meta-analysis. J R Coll Phys London 1994;28(1):39-45.
Silagy CA, Neil HA. A meta-analysis of the effect of garlic on blood pressure. J Hyperten 1994;12:463-8.
Warshafsky S, Kamer R, Sivak S. Effect of garlic on total serum cholesterol: A meta-analysis. Ann Int Med 1993;119(7)599-605.