Sandra Justice, P.D., FACA
Garlic may well be the wonder drug of the herbal world. Greek and Roman physicians, such as Hippocrates, Galen, and Dioscorides, recommended garlic for a vast array of conditions including parasites, respiratory problems, weight loss, poor digestion, and low energy. Garlic has also been an important part of traditional Chinese medical history. Garlic was used for digestive difficulties, diarrhea, dysentery, colds, and tuberculosis as early as 510 AD. In 1858, Louis Pasteur engaged in studies to confirm the antibacterial activity of garlic. Albert Schweitzer employed garlic for the treatment of amoebic dysentery, cholera, and typhus while working as a missionary in Africa.
Applications in Cardiovascular Disease
Garlic effectively lowers serum cholesterol and triglycerides, inhibits blood clotting, and has a mild antihypertensive effect.
Garlic interferes with the hepatic metabolism of cholesterol resulting in less release into the serum. Garlic also mildly elevates HDL-cholesterol and prevents oxidation of LDL-cholesterol.
The ability of garlic to provide some protection against coronary thrombosis and stroke is believed to be directly related to its ability to inhibit aggregation of the blood platelets. This property is due to ajoene and is enhanced by other break-down products of allicin. As a clot-preventing agent, ajoene is at least as potent as aspirin.
Garlic exerts a mild antihypertensive effect. Analysis of studies has shown a decrease in systolic pressure of 20 to 30 mm Hg and diastolic pressure of 10 to 20 mm Hg. This is most likely due to its ability to improve the circulatory efficiency.
Antioxidant activity has also been noted for garlic. Regular garlic intake reduces the risk of esophageal, stomach, and colon cancer. This may be partly due to garlic’s ability to reduce the formation of N-nitroso compounds like nitrosamine. Animal studies have also shown garlic and its sulfur compounds inhibit the growth of different cancer cells, notably breast and skin tumors. What should I look for in a garlic supplement?
The majority of the beneficial effects of garlic are attributed to allicin and its other sulfur- containing compounds like diallyl disulfide, diallyl trisulfide, vinyl-dithiins, and ajoene found in fresh crushed garlic. Research suggests that supplements work best when they most closely approximate eating raw garlic. Carefully prepared garlic powder will yield only 4% less allicin than raw garlic.
Allicin is mainly responsible for the pungent odor of garlic. It is formed by the action of the enzyme alliinase on garlic’s “mother ” compound, alliin. Since the enzyme is inactivated by heat, oxygen, or water the cooked or aged garlic preparations are not nearly as potent medicinally as raw garlic. Some manufacturers have developed highly sophisticated methods to provide the full benefits of garlic (concentrated for alliin) in odorless, enteric-coated garlic powder supplements. Consult a healthcare professional involved in nutritional programming to find the most effective product for you.
For therapeutic purposes, chew two to three fresh cloves of garlic daily. Stir-frying the cloves for a few minutes will help eliminate the garlic breath and after taste. For those adverse to the odor, odor-controlled, enteric-coated garlic powder supplements can be used. The supplement should provide at least 4,000 mcg allicin daily. Treatment should be evaluated over a three to six month period.
Side Effects/ Contraindications
Consumption at the doses listed above rarely poses health risks. Heartburn and flatulence(gas) may be experienced by some persons sensitive to garlic. At higher allicin dosages, some persons may experience a garlic taste and even notice a garlic odor when they perspire. This is best avoided by taking garlic supplements in two to three divided dosages daily. There are rare reports of allergic reactions to garlic. Persons taking anticoagulant drugs should use garlic with caution. Garlic reduces blood sugar so it may affect glucose control in diabetics. There are no known contraindications to the use of garlic during pregnancy. Garlic should not be used by women who are breast-feeding because it can pass to the breast milk and cause colic in infants.
Garlic should not be considered a replacement for your prescribed medications. It may serve as a preventative tool or be useful as an addition to your drug therapy. As always, it is wise to consult your physician or pharmacist before adding a nutrient to your present drug therapy.
Honored Past and Exciting Future
Garlic is a valuable medicine, especially for the heart and vascular system. In the past two decades, 2,000 studies conducted by the world’s top researchers have established garlic’s potential impact on the most serious modern diseases. Based on current knowledge, there seems to be more truth than poetry in an old Welsh rhyme:
” Eat leeks in March and wild garlic in May,
And all the year after physicians may play.”