Garlic shows activity against many infectious bacterial, viral and fungal diseases, including staphylococcus, streptococcus, and salmonella bacteria. It also helps prevent blood platelet aggregation, which makes it of use in addressing problems of the circulatory system. It is employed in the treatment of arteriosclerosis, asthma, candida, catarrh, diabetes, high cholesterol, hypertension, obesity, tuberculosis, whooping cough, and worms.
Topically, garlic can be prepared as a bolus to treat a yeast infection or an enema to treat dysentery. An uncut clove can be used as a suppository to treat haemorrhoids. Garlic-infused oil can be used as ear drops to treat ear infection or as a wash to treat gangrenous wounds and snakebite.
ail commun (French); Knoblauch (German); knoflook (Dutch); ai, aglio (Italian); alho (Portuguese); ajo commún (Spanish); vitlök (Swedish); tschesnok (Russian; suan, da suan (Chinese); Rasona (Sanskrit); Lasan (Hindi); ninniku (Japanese); toum (Arabic); Ail De Cuisine, Bawang Poetih, Bawang Puteh, Cropleek, Cultivated Garlic, Hsiao Suan, Lai, Lasan, Poor Man’s Treacle, Rosina, Samersaq, Sarimsak, Sir, Suan, Thum; taisan (Japanese); taesan (Korean)
Grown in the Mediterranean and Central Asia for centuries, garlic was widely used as medicine by the ancients. It was found in King Tut’s tomb and was eaten for endurance by the slaves who constructed the great Cheops pyramid. Greek wrestlers would chew a few cloves of garlic before fighting bouts to give themselves strength and courage.
The East Indian herbalist Charaka said in the first century A.D. that garlic would be worth its weight in gold if it weren’t for its smell. Garlic has been used by rich and poor alike through the years to keep away disease, evil spirits, moles and racing competitors. It was the main ingredient in the “Four Thieves Vinegar” used by 4 Marseilles thieves who confessed that “garlek” protected them while they robbed plague victims’ bodies.
In the early 18th century, it was used by French priests to protect themselves from a highly contagious fever in London’s deprived sections. European doctors in World War I and World War II applied sterilised swabs of sphagnum moss and garlic to dressing wounds and prevent gangrene.
Diaphoretic. Expectorant. Spasmolytic. Antiseptic. Bacteriostatic. Antiviral. Promotes Leucocytosis. Hypotensive. Anthelmintic.
Arteriosclerosis, atherosclerosis, impaired peripheral circulation, hypercholesterolaemia, hyperlipidaemia, hypertension, gastrointestinal system infection, respiratory tract infection
Atherosclerosis and high cholesterol.
Garlic can help prevent atherosclerosis by lowering cholesterol and triglyceride levels in the blood, inhibiting platelet stickiness, and increasing fibrinolysis, which results in a slowing of blood coagulation. Garlic preparations have been found to reduce the size of plaque deposits in animals by nearly 50 percent. In a four-year double-blind study of 152 individuals, standardised garlic powder at a dosage of 900 milligrams daily significantly slowed the development of atherosclerosis as measured by ultrasound. Another study, which measured the flexibility of the aorta in 200 individuals, reported that the participants taking garlic had more flexibility, indicating less atherosclerosis. Reviews of double-blind studies in humans have found that garlic lowered cholesterol levels in adults by approximately 6 to 12 percent, low-density lipoprotein (LDL, or “bad”) cholesterol by 4 to 15 percent, and triglycerides by 15 percent. The high-density lipoprotein (HDL, or “good”) cholesterol rose 0 to 22 percent. The corresponding dosages of garlic were 900 to 1,200 milligrams a day with at least 10 milligrams alliin (or total allicin potential of 4,000 micrograms). However, several more recent double-blind studies have found no benefit. At present, it appears that garlic’s effects on cholesterol are modest at best and considered a clinically inefficient way to lower cholesterol. The authors concluded that garlic looked promising for reducing the clumping of platelets, but as for lowering total and LDL cholesterol and blood pressure and reducing oxidative stress, the studies have not been definitive.
Despite the conflicting data, a few studies showed promise for using garlic to improve blood lipids. In one study, patients at high risk for heart disease who used 4 millilitres (1,200 milligrams) of aged garlic extract had significantly less plaque buildup in their arteries compared to a control group. Garlic also appeared to protect blood vessels from toxic homocysteine, which is often elevated in cardiovascular disease. It seems that garlic prevents a decrease in bioavailable nitric oxide. Patients with heart disease risk factors or vascular problems took aged garlic extract for six weeks.
In a ten-year study, healthy subjects received Allicor, an A. sativum preparation, for twelve months and were followed for heart disease risks. The study found that 13 percent of the men and 7 percent of the women experienced a reduced risk compared to people who don’t take garlic for many aspects of heart problems, such as lower high blood cholesterol and higher HDL (“good”) cholesterol.
There have been hundreds of studies on the impact of garlic on cancer. In one study, the use of garlic (the highest intake was 9 to 10 cloves a week compared to 0 to 1) was associated with lower rates of cancer of the colon (40 percent) and stomach (47 percent) in both men and women. Also, garlic intake was inversely associated with cancer of the prostate and endometrium. In another study, patients with precancerous lesions of the large intestine benefited from using a large dose (2.4 millilitres per day) of aged garlic extract (AGE). After one year, there were fewer and smaller adenomas (benign tumours) in the AGE group. In patients with advanced cancer, AGE improved natural killer (NK) cell numbers and activity, but the quality of life of the patients did not change.
Garlic contains compounds that prevent tumours from developing their own blood supplies stop tumour formation after exposure to carcinogenic chemicals, and inhibit the spread of tumours once they have started. Other compounds in garlic reduce the production of toxic free radicals in liver and lung tissue and retard the proliferation of hormone-sensitive breast and prostate cancer cells. Garlic has been found to prevent the growth of the bacterium Helicobacter pylori, one of the risk factors for stomach cancer. However, epidemiological data do not support the use of garlic as an anticancer agent.
Garlic works well with other anticancer treatments. Garlic powder, usually taken in tablet form, increases the effectiveness of selenium supplements in preventing the growth and spread of breast cancer. Animal studies have found that garlic protects tissues from the effects of whole-body radiation. However, garlic is not appropriate for people undergoing treatment with recombinant tumour necrosis factor (rhTNF), since a combination of chemicals in the herb reduces the activity of rhTNF.
Garlic helps strengthen the immune system against infection by activating “germ-eating” macrophages, cells that are produced by the immune system. In one study, participants who consumed 600 milligrams of garlic powder every day for three months showed significant increases in the number of macrophages in their bloodstream. Garlic has antifungal and antibacterial effects, but these have not been demonstrated in human studies. Garlic appears to have only 1 percent of the strength of penicillin against certain types of bacterial infections. Therefore, it should not be considered a substitute for conventional antibiotics, but it can be used as support against some bacterial infections. Check with your doctor before using these medications with garlic.
- The efficacy of Garlic as a carminative has been demonstrated in human studies. A clinical study of 29 patients taking two tablets daily (~1000mg/day) of a dried garlic preparation showed that garlic relieved epigastric and abdominal distress, belching, flatulence, colic, and nausea, as compared with placebo. It was concluded that garlic sedated the stomach and intestines, and relaxed spasms, retarded hyperperistalsis, and dispersed gas.
- A meta-analysis of the effects of Garlic on serum lipids and lipoproteins reviewed 25 randomised, controlled trials (published and unpublished) and selected 16 with data from 952 subjects to include in the analysis. The total daily dose of garlic was 600–900 mg of dried garlic powder, or 10g of raw garlic, or 18mg of garlic oil, or aged garlic extracts (dosage not stated). The median duration of the therapy was 12 weeks. Overall, the subjects receiving garlic supplementation (powder or non-powder) showed a 12% reduction (average) in total cholesterol and a 13% reduction (powder only) in serum triglycerides. Meta-analysis of the clinical studies confirmed the lipid-lowering action of garlic. A systematic review of the lipid-lowering potential of a dried garlic powder preparation in eight studies with 500 subjects had similar findings. In seven of the eight studies reviewed, a daily dose of 600–900mg of garlic powder reduced serum cholesterol and triglyceride levels by 5–20%. The review concluded that garlic powder preparations do have lipid-lowering potential.
- In a 3-year intervention study, 432 patients with myocardial infarction were treated with either an ether-extracted garlic oil (0.1 mg/kg/day, corresponding to 2 g fresh garlic daily) or a placebo. In the group treated with garlic, there were 35% fewer new heart attacks and 45% fewer deaths than in the control group. The serum lipid concentrations of the treated patients were also reduced.
- Oral administration of garlic powder (800mg/day) to 120 patients for 4 weeks in a double-blind, placebo-controlled study decreased the average blood glucose by 11.6%. Another study found no such activity after dosing non-insulin-dependent patients with 700 mg/day of a spray-dried garlic preparation for 1 month.
Dosage (Divided Daily)
• Dried Powder: 500 – 3,000mg
• Ratio Extract: 4 – 12mg Alliin
• Fresh Garlic: 2 – 5 gms
Contraindicated in those with known sensitivity.
Garlic may cause gastric irritation, allergy, contact dermatitis, and other skin reactions, and increased body odour.
Interactions with other drugs
Patients on warfarin therapy should be warned that garlic supplements may increase bleeding times. Blood clotting times have been reported to double in patients taking warfarin and garlic supplements.
Balch, P. A., & Bell, S. J. (2012). Prescription for herbal healing (2nd ed.). New York, N.Y.: Avery.
- British Herbal Medicine Association. Scientific Committee. (1983). British herbal pharmacopoeia (Consolidated ed.). West Yorkshire: British Herbal Medicine Association.
- Herbalpedia (2013)
- Mars, B. (2007). The desktop guide to herbal medicine: the ultimate multidisciplinary reference to the amazing realm of healing plants, in a quick-study, one-stop guide. Laguna Beach, CA: Basic Health Pub.
World Health Organization., & Ebrary. (1999). WHO monographs on selected medicinal plants (pp. electronic text.). Retrieved from https://virtual.anu.edu.au/login/?url=http://site.ebrary.com/lib/anuau/Top?id=10040306
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