Garlic (Allium Savitum)
Garlic, a member of the lily family, is a perennial plant that is cultivated worldwide. The garlic bulb is composed of individual cloves enclosed in a white skin. It is the bulb, either fresh or dehydrated, that is used as a spice or medicinal herb.
Garlic has been used throughout history for the treatment of a wide variety of conditions. Its usage predates written history. Sanskrit records document the use of garlic remedies approximately 5000 years ago, whereas the Chinese have been using it for at least 3000 years. The Codex Ebers, an Egyptian medical papyrus dating to about 1550 BC, mentions garlic as an effective remedy for various ailments, including hypertension, headache, bites, worms, and tumors. Hippocrates, Aristotle, and Pliny cited numerous therapeutic uses for garlic. In general, garlic has been used throughout the world to treat coughs, toothache, earache, dandruff, hypertension, atherosclerosis, hysteria, diarrhea, dysentery, diphtheria, vaginitis, and many other conditions. Stories, verse, and folklore (such as its alleged ability to ward off vampires) give historical documentation to garlic’s power. Sir John Harrington, in writing The Englishman’s Doctor in 1609, summarized garlic’s virtues and faults: Garlic then have power to save from death Bear with it though it maketh unsavory breath, And scorn not garlic like some that think It only maketh men wink and drink and stink. In 1721, during a widespread plague in Marseilles, France, four condemned criminals were recruited to bury the dead. The gravediggers proved to be immune to the disease. Their secret was a concoction they drank consisting of macerated garlic in wine. This became known as vinaigre des quatre voleurs (“ four thieves” vinegar), and it is still available in France today. Garlic’s antibiotic activity was noted by Pasteur in 1858. Garlic was used by Albert Schweitzer in Africa to treat amebic dysentery and as an antiseptic in the prevention of gangrene during World Wars I and II.
ANTICANCER EFFECTS
The famous Greek physician Hippocrates prescribed eating garlic as a treatment for cancer. Animal research and some human studies suggest this may have been well-founded advice. It must be kept in mind that much of garlic’s anticancer effect is likely an indirect effect via its impact on the immune system. Nonetheless, several garlic components have displayed significant anticancer effects, including enhancing phase II metabolizing enzymes, antioxidant properties, inhibition of the formation of nitrosamines, direct tumor growth inhibition, and the ability to induce apoptosis. Human studies showing garlic’s anticancer effects are largely based on epidemiologic studies. These studies typically show an inverse relationship between cancer rates and garlic consumption. Human studies have also shown that garlic inhibits the formation of nitrosamines (powerful cancer-causing compounds formed during digestion).
ANTIMICROBIAL ACTIVITY
Garlic has broad-spectrum antimicrobial activity against many genera of bacteria, viruses, worms, and fungi. This supports the historical use of garlic in the treatment of various infectious conditions.
IMMUNE-ENHANCING EFFECTS
Extensive research has shown that garlic has many immune-potentiating properties, most of which are thought to be due to volatile factors composed of sulfur-containing compounds: allicin, diallyl disulfide, diallyl trisulfide, and others. For example, in vitro studies with allicin showed that it stimulated enhanced cell-mediated cytotoxicity in human peripheral mononuclear cells. In animal models, multiple administration of allicin elicited marked antitumor effects via immunostimulatory mechanisms. Fresh garlic, commercial products containing allicin, and aged garlic preparations have all shown these immune-enhancing properties. Garlic has been shown to enhance the pathogen-attacking activity of T cells, neutrophils, and macrophages, which increase the secretion of interleukin and natural killer (NK) cell activity. The increase in killer cell activity was a remarkable 140% in those who ate the equivalent of two bulbs a day and 156% in those who consumed 1800 mg of odorless, aged garlic.
CARDIOVASCULAR EFFECTS
Garlic appears to be an important protective factor against heart disease and strokes via its ability to affect the process of atherosclerosis at many steps. Specifically, garlic is recommended primarily for its ability to lower cholesterol and blood pressure in the attempt to reduce the risk of dying prematurely from a heart attack or stroke. In addition to the use of garlic preparations, garlic consumption as a food is encouraged in patients with high cholesterol levels, high blood pressure, and diabetes.
DOSAGE
On the basis of extensive clinical research, a commercial garlic product should provide a daily dose equal to at least 4000 mg of fresh garlic. This dosage translates to at least 10 mg alliin or a total allicin potential of 4000 µg. Alternatively, AGE at a dosage of 2.4 to 7.2 g/ day can be used.
SAFETY
For the vast majority of individuals, garlic is nontoxic at the dosages commonly used. For some, however, it can irritate the digestive tract and cause heartburn. Others are apparently unable to effectively detoxify allicin and other sulfur-containing components. Prolonged feeding of large amounts of raw garlic to rats resulted in anemia, weight loss, and failure to grow. Although the exact toxicity of garlic has yet to be definitively determined, side effects are rare at the recommended dosage. Garlic is thought to be safe during pregnancy and breastfeeding. Two studies showed that babies liked breast milk better from mothers who ate garlic.