Header Header








Tell me about...


What is garlic?

One of the most popular herbs in existence, garlic is held in high regard in many parts of the world for its pungent aroma and flavor. It is often used as a flavoring or complement for a variety of foods, particularly Mediterranean cuisine.

Sulfur compounds give garlic its distinctive aroma and help account for some of its flavor. They also appear to be responsible for most of its medicinal properties, although a pair of trace minerals (germanium and selenium) may also play a role.

An inert compound in garlic, alliin, is converted to another compound named allicin once a clove is cut or crushed. In Europe, standardized garlic extracts are supposed to contain at least 0.45 percent allicin.

Why do we need garlic? What is it used for?

The use of garlic as a medicinal is traced back to ancient Greece and Egypt. For instance, the Ebers Papyrus -- an ancient medicinal scroll fating to 1550 BC -- mentions 22 herbal remedies containing garlic. Hippocrates, the "father of medicine," prescribed garlic for conditions ranging from leprosy and toothaches to chest pain.

Modern research has shown garlic to contain a number of antibacterial, antifungal and other healing properties. For instance, garlic has been shown to lower levels of low density lipoprotein (LDL) cholesterol in some individuals, while other research has shown increases in beneficial HDL (high density lipoprotein) with long-term use.

Several garlic-derived chemicals can help slow blood clotting by keeping blood platelets from clumping together. In addition, garlic helps break up or prevent blood clots. Since many heart attacks and strokes are believed to be caused by spontaneous clots in blood vessels, these anticoagulant actions may be very helpful in stroke and heart attack prevention.

Test tube research has established that garlic extracts are active against a range of disease-causing bacteria, including staphylococcus aureus and streptococcus pneumoniae. It is only about one percent as active as penicillin, however. Garlic extract can also fight helicobacter pylori, a bacterium that causes stomach ulcers.

Animal research has demonstrated that garlic has the potential to improve resistance to tumors. Other tests conducted on rats and dogs have also shown that garlic can return irregular heart rhythms back to normal.

One of the most intriguing possibilities for garlic is that regular consumption may help prevent cancer. Studies in China comparing people in one region where garlic is commonly eaten (20 grams a day, on average) with those in another region where daily consumption is less than half a clove found that the people who ate more garlic were much less likely to suffer stomach cancer. Other studies have indicated that people who eat garlic more often seem less susceptible to colon cancer.

How much garlic should I take?

The National Academy of Sciences has yet to specify a recommended daily allowance for garlic. As a result, recommended doses vary depending on type of condition a patient may have and the type of health practitioner providing information.

The Complete German Commission E Monographs Therapeutic Guide to Herbal Medicines recommends consumption of four grams of fresh garlic daily. Other publications and studies have recommended much lower doses (5-10 milligrams/day).

What forms of garlic are available?

Garlic is available in many forms, including fresh bulbs, oil-based extracts, steam-distilled extracts and dried powder. Minced and chopped varieties are also available at most supermarkets.

To maximize the anti-cancer activity of fresh garlic in cooking, health professionals recommend that it be crushed or minced at least ten minutes before heating.

What can happen if I take too much garlic? Are there any interactions I should be aware of? What precautions should I take?

Most people appear to tolerate garlic well, but some individuals may experience gastrointestinal irritation. People who handle garlic products occasionally develop a skin reaction on exposure. Ingestion of fresh garlic and most extracts may also result in a characteristic breath odor.

Although there are no studies of drug interactions, in theory garlic may increase the risk of bleeding in people taking aspirin or blood-thinning medications such as coumadin. There is also a possibility that garlic could interact with drugs such as DiaBeta or Glucotrol that lower blood sugar. Careful monitoring is recommended for anyone combining garlic products with prescription drugs.

Garlic appears to inhibit an enzyme called CYP 2E1. In most cases, this interference is viewed positively, because CYP 2E1 can make carcinogens more dangerous. However, CYP 2E1 is also involved in the metabolism of acetaminophen and a muscle relaxant called chlorzoxazone. These drugs could possibly remain in the body longer in people who are taking or eating garlic.

People with low thyroid function should also be aware that concentrated garlic products may keep the thyroid gland from utilizing iodine properly. This could aggravate an underactive thyroid condition.

Other Resources :

The More You Know About Garlic

The More You Know About Nutrition

Subscribe to "To Your Health" our free e-mail health newsletter.

Ask a DC

Find a Chiropractor Near You


• Graedon J, Graedon T. The People's Pharmacy Guide To Home And Herbal Remedies. New York: St. Martins, LLC, 1999.
• Ahsan M, Islam SN. Garlic: a broad spectrum antibacterial agent effective against common pathogenic bacteria. Fitoterapia 1996;67(4):374-376.
• Blumenthal M, et al. The Complete German Commission E Monographs Therapeutic Guide to Herbal Medicines. Boston: Integrative Medicine Communications, 1998, p. 134.
• Aqel MB, Gharaibah MN, Salhab AS. Direct relaxant effects of garlic juice on smooth and cardiac muscles. Journal of Ethnopharmacology 1991;33:13-19.
• Barrie SA, Wright JV, Pizzorno JE. Effects of garlic oil on platelet aggregation, serum lipids and blood pressure in humans. Journal of Orthomolecular Medicine 1987;2(1):15-21.
• Cellini L, Di Campli E, Masulli M, et al. Inhibition of helicobacter pylori by garlic extract (allium sativum). FEMS Immunology and Medical Microbiology 1996;13:273-277.
• De A Santos OS, Johns RA. Effects of garlic powder and garlic oil preparations on blood lipids, blood pressure and well-being. British Journal of Clinical Research 1995;6:91-100.
• Kiesewetter H, Jung F, Pindur G, et al. Effect of garlic on thrombocyte aggregation, microcirculation, and other risk factors. International Journal of Clinical Pharmacology, Therapy, and Toxicology 1991;29(4):151-155.
• Moriguchi T, Saito H, Nishiyama N. Anti-ageing effect of aged garlic extract in the inbred brain atrophy mouse model. Clinical and Experimental Pharmacology and Physiology 1997;24:235-242.
• Nagourney RA. Garlic: medicinal food or nutritious medicine? Journal of Medicinal Food 1998;1(1):13-28.
• Singh KV, Shukla NP. Activity on multiple resistant bacteria of garlic (allium sativum) extract. Fitoterapia 1984;55(5):313-315.
• You W-C, Blot WJ, Chang Y-S, et al. Allium vegetables and reduced risk of stomach cancer. Journal of the National Cancer Institute 1989; 81(2): 162-164.


Designed by Dynamic Chiropractic

To report inappropriate ads,click here

Advertising Information | About Us | DC Deals & Events Newsletter | ChiroFind | ChiroPoll | Chiropractic Directory
Chiropractic Mailing Lists | Chiropractic Product Showcase | Classified Advertising | DC News Update Newsletter
Discussion Forums | Event Calendar | For Chiropractic Students | Link to Us | Meet the Staff
Other Sources | Previous Issues | Research Review Newsletter | Site Map | Webcasts

[ Home ] [ Contact Us ]

Other MPA Media Sites:
DynamicChiropractic | DynamicChiropractic Canada | ChiroFind | ToYourHealth | AcupunctureToday
MassageToday | ChiropracticResearchReview | SpaTherapy | NutritionalWellness | NaturopathyDigest

Privacy Policy | User Agreement

All Rights Reserved, Dynamic Chiropractic, 2011.