Garlic Health İmportance and Effects

Garlic (Allium sativum) is a species in the onion genus, Allium. Garlic is rich in a substance known as alliin. Once garlic is crushed, called allinase, converts alliin into different compound known as allicin. While alliin is relatively odourless, allicin is responsible for garlic’s typical pungent odour and taste. Crushing a garlic clove causes allicin formation within 10 to 60 seconds.

Garlic Health İmportance and Benefits

At the present time, garlic is used to help avoid heart disease, including atherosclerosis or hardening of the arteries, high blood pressure, and to boost the immune system. The combination of anti-inflammatory and anti-oxidative stress compounds in garlic makes it a important food for cardiovascular support, particularly in terms of chronic degenerative cardiovascular problems like atherosclerosis. Garlic has been tried for treating an enlarged prostate, diabetes, osteoarthritis, hayfever, high blood pressure, cold and flu. Garlic contains biologically active components including alliin, allicin, alliinase and unique sulfur compounds. Allicin along with sulfur based compounds act as strong antibiotic, anti-viral, and anti-fungal agents that have immune stimulating effect.

Natural Antibiotic

GarlicGarlic, have natural antibiotic effects. Garlic owes this strong antibiotic effect to allicin. The famous scientist Louis Pasteur performed some of the original work showing that garlic could kill bacteria.

A important problem with chemical antibiotic drugs is that they can promote the development of resistant strains of bacteria. Garlic does not seem to produce such resistant strains, and may be effective against strains that have become resistant to chemical antibiotic drugs. European scientists in the late 1970s analyzed garlic juice against a group of 10 different bacteria and yeasts. They found that garlic was effective against all of them, and also found a “complete absence of development of resistance.” A study, performed on mice, found that garlic extract was able to inhibit a type of staph infection that’s become increasingly resistant to antibiotic drugs and increasingly common in hospitals. 16 hours after the mice were infected with the pathogen, garlic  was fed to them. After 24 hours, garlic extract was found to have been preventive against the pathogen and to have significantly reduced the infection

According to scientists from the “Department of Clinical Pharmacology at the PLA General Hospital”, allicin in garlic has the capability to destroy a wide range of bacteria, particularly if used in conjunction with standard antibiotic drugs. Scientists at “Washington State University” have found that a compound in garlic is 100 times more effective than two known antibiotics at fighting the Campylobacter bacterium, one of the most common causes of intestinal illness.

In a study 2004 edition of the Journal of  Medicinal Food showed that garlic possesses important antibacterial effect against a variety of bacteria including Streptococcus pneumonia and Staphylococcus aureus, which may cause secondary infections in bronchitis patients. Researches published by Lu and WSU colleagues in “Applied and Environmental Microbiology and Analytical Chemistry” found diallyl sulfide and other organosulfur compounds effectively kill food-borne pathogens, such as Escherichia coli O157:H7 and Listeria monocytogenes.

Garlic can kill up to 90% of fungal species that are associated with ringworm, study reported in the April 1995 edition of the International Journal of Dermatology. In a study reported in 1999 found that a cream made from the garlic constituent ajoene was just as strong for fungal skin infections as the medication terbinafine. Garlic can disrupt the metabolism of fungi by inhibiting the activity of some significant metabolic enzymes, including phenoloxidase, protease, cellulase and amylase, according to an article reported in 2000 in the medical journal Mycopathologia.

Blood Pressure

The cardioprotective effects of garlic may partly rest on the production of e H2S (hydrogen sulfid) gas.When produced and released from our red blood cells, this hydrogen sulfide gas gas can help dilate blood vessels and help keep  blood pressure under control. New research published in the Journal of  Hypertension demonstrated that garlic consumption could decrease blood pressure by 5 to 10 pc. The researchers concluded that only this effect alone might lessen heart disease and stroke rates by up to 40 and 35 pc respectively. (Most of the researches on high blood pressure have used a specific formulation called Kwai).


Various researches demonstrate that garlic could benefit your heart health. A recent study shows red blood cells process compounds from digested garlic and turn them into the cell messenger hydrogen sulfide, which relaxes blood vessels and increases blood flow. Thus, eating garlic may enhance our natural supply of this important chemical and play a role in reducing the risk of heart disease.

Garlic has the ability to lessen the tendency for the formation of blood clot. As blood clots can trigger heart attacks and strokes, this tendency to thin the blood is likely to help avoid these problems. Platelet aggregation plays a role in the development of stroke and heart illness. Garlic extract inhibits formation of thromboxane A2, a compound that binds to platelets and activates their clotting actions. Scientists isolated a component of garlic oil that inhibits platelet aggregation and identified it as methylallyl trisulphide. The purified compound inhibits adenosine diphosphate-induced platelet aggregation at a concentration of less than 10 mmol/L in plasma.

This nutrient indirectly effects atherosclerosis by reduction of hyperlipidemia, hypertension, and probably diabetes mellitus and prevents thrombus formation. Also, in animal models, garlic causes direct antiatherogenic and antiatherosclerotic effects at the level of artery wall. In 1999, Atherosclerosis reported a study which found that supplementing using AGE (aged garlic extract) instead of raw garlic produced important results as an anti-atherosclerosis agent. One study that was reported in the journal Atherosclerosis in 1999, investigated the effects of taking 900 milligrams of garlic powder, standardized for 0.6 % allicin content, on atherosclerosis plaque in carotid and femoral arteries. Findings demonstrated that garlic prevented and possibly slowed the progression of arteriosclerosis in individuals between 50 and 80 years of age after 4 years of therapy. In one study, 432 participant who had suffered a heart attack were given either garlic oil extract or no therapy over a period of three years.  The findings demonstrated a important reduction of second heart attacks and a 50% decrease in death rate among those taking garlic.

Immune Booster

Garlic activate phagocytes, B-Cells, and T-cells. For example, diallyl trisulfide, was found to activate natural killer cells and macrophages directly, and indirectly to increase B-cell activity to make antibodies. Also enhances the production of several immune activating chemicals called cytokines, including interleukin-2 and tumor necrosis factor-alpha. A preliminary study, 7 AIDS patients all had normal T-cell activity after 3 months of taking the equivalent of two or four garlic cloves each day. In one study immune parameters of the blood were measured after subjects — elderly patients — took a garlic powder preparation for 3 months. The dose was just 600 milligrams of the powder per day, the equivalent of less than one-third of a garlic clove. Blood analysis demonstrated an increase in phagocytosis of the white blood cells, and also increased numbers of lymphocytes, responsible for cell-mediated immunity.


Some population studies show an association between increased intake of garlic and reduced risk of certain cancers, including cancers of the stomach, esophagus, colon, breast and pancreas. Experts believe the components in garlic called allyl sulfides and bioflavonoids may be key to the research observations of usually lower incidence of  cancer in people who consume large amounts of garlic compared with those who eat less. Garlic might stimulate both humoral and cellular immunity, causing T-cell proliferation, restoring suppressed antibody responses, and stimulating macrophage cytotoxicity on tumor cells. In patients with advanced cancers, AGE (aged garlic extract) improved natural killer cell number and activity. Researches demonstrate that allium derivatives inhibit proliferation of the human prostate cancer cell line (LNCaP) and the human breast cancer cell line (MCF-7). The antineoplastic effect of garlic has been investigated in mice injected with cancer cells pretreated with a garlic extract. No deaths occurred in this therapy group for up to six months, while mice injected with untreated cancer cells died within 16 days.

Scientists who reviewed seven studies found a 30% decreased in risk of colorectal cancer among people who ate a lot of raw or cooked garlic. A study performed at “Case Western Reserve University” indicated that garlic may help decrease the occurrence rate of polyps  (pre-cancerous tumors) in the large intestine. A study performed at the “Fred Hutchinson Cancer Research Center” found that eating a teaspoon of fresh garlic and a half cup of onions per day increases the levels of a important enzyme for removing toxins in the blood cells of healthy women. Various cancers are thought to be caused by damage to DNA, usually induced by environmental toxins. In one study reported in 2006 in Cancer Letters, a compound from garlic named ajoene inhibited growth of melanoma cells in culture and suppressed spread of melanoma to other organs in experimental animals. Also, garlic may preserve against certain cancers by halting cell cycle progression and inducing apoptosis of cancer cells as well as by decreasing angiogenesis and influencing carcinogen metabolism.


Garlic, fresh or carefully dried, consists of the main bulb with several secondary bulbs  of A. sativum and its preparations in effective dosage. Garlic contains alliin and its degradation products, and sulfur-containing essential oils. Recommended daily dose is generally; 900 mg daily of a garlic powder extract standardized to contain 1.3% alliin, providing approximately 12,000 mcg of alliin daily. The World Heath Organization (WHO) recommends a daily dose of 2 to 5 g of fresh garlic. German researchers recommend a dose of 1-4 cloves a day which provides around 4,000mcg of alliin. (each clove is about 1 gram).

Side Effects

Garlic may alter the function of certain prescription drugs. Garlic can thin the blood  in a manner similar to aspirin. Too much garlic can enhance  risk for bleeding during or after surgery. Garlic has been found to interfere with the effectiveness of saquinavir, a medication used to treat HIV.

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