Garlic (Allium sativum) is a strong-smelling, pungent-tasting herb. It is a close relative of onion and is native to Central Asia. It has been used as a food-flavoring agent and as a traditional medicine. Mankind recognized the curative qualities of this magic herb over 3,000 years ago. Sir Louis Pasteur, the scientist who discovered pasteurization, effectively utilized the anti-bacterial qualities of this herb all the way back in 1858.  As little as one clove per day may bring a vast improvement in your overall health, while 2 to 3 cloves could prevent an attack of the common cold. World War I medical surgeons also used the garlic juice as an antiseptic for treating war wounds.
Those are famous words from the ancient Greek physician Hippocrates, often called the father of Western medicine.He actually used to prescribe garlic to treat a variety of medical conditions.Modern science has recently confirmed many of these beneficial health effects.
Garlic contains useful minerals such as phosphorus, potassium, magnesium, zinc, calcium, and iron, as well as trace minerals like iodine, sulfur, and chlorine.  It is a rich source of vitamins like folate, thiamine, niacin, and vitamin C, A, K, and B6. In terms of organic compounds, it is one of the rare sources of allicin, allisatin 1, and allisatin 2. The herb is very low in calories, saturated fats, and sodium.
1.Help Control Blood Pressure
Garlic has profound effects on lowering blood pressure, as was revealed in a study conducted on persons using anti-hypertensive medications and yet having poor control over it. Garlic supplementation in the vicinity of 1g/ day (in the form of standardized garlic capsules) was found to bring about immense reduction in blood pressure levels, as to be comparable to prescription medications in many cases. This action is thought to be due to garlic’s polysulfides which have a vasodilatory action on blood vessels, widening them and lowering vessel wall tension.
In animal and cell-based studies, aged garlic extract stimulates white blood cells (lymphocytes, macrophages, monocytes, and neutrophils) by increasing glutathione. White blood cells are immune cells that provide protection against infections, while glutathione is an antioxidant that protects immune cells from free radicals.
3.Reduces Levels of LDL Cholesterol
The use of garlic for its cholesterol reducing effects is one of its most popular roles across the world, and is something it does fairly well; being able to reduce serum LDL by as much as 10-15%. Many people all over the world consume crushed garlic cloves for this purpose with fair success. It is important to note that garlic consumption has no effect on HDL or triglyceride levels.
In a study (DB-RCT) of 120 individuals, aged garlic extract reduced the severity of colds and the flu by increasing the number of immune cells (T cells and NK cells) and by boosting the immune system. Aged garlic extract increases the activity of immune cells while lowering inflammatory proteins (cytokines).
6.Garlic May Help Treat HIV Infection
In a cell-based study, diallyl disulfide in garlic inhibited cell growth and selectively killed HIV-infected immune cells. Diallyl disulfide also inhibits virus replication by decreasing the production of proteins involved in HIV replication.
Ajoene, a garlic extract, prevents normal blood cells from fusing with HIV-infected cells and inhibits HIV replication in infected cells. Ajoene may prevent cell fusion by inactivating platelet integrins (a protein that causes blood cells to fuse together) in the blood.
7.Help Prevent Neuro-Degenerative Diseases
Neuro-degenerative diseases such as Alzheimer’s, Parkinson’s and dementia have a strong link to chronic inflammation in the brain, resulting in accumulation of certain proteins that damage neurons. The end result is accelerated aging and mental decline. Garlic supplementation has been shown to increase the levels of anti-oxidant enzymes produced by the liver, helping to buffer the action of free radicals and reduce inflammation. This, coupled with reductions to blood pressure and cholesterol offer fair support against these diseases.
Garlic treats parasitic intestinal infections like giardiasis and tapeworm infections in rats.Allicin in garlic disrupts the mobility, food absorption, and reproduction of the parasites by blocking fat synthesis in the parasites. Garlic also promotes immune function and strengthens the body’s defense mechanism against parasitic infections by stimulating white blood cells.
9.Remove Heavy Metal Toxins From The Body
Heavy metals are extremely toxic, and have a way of embedding themselves in deep fat layers and in organ tissue. This is very troublesome, as it can cause a host of untoward effects, ranging from cancer to organ failure and more. Garlic can help to chelate these heavy metals and promote their excretion by the body. If your job entails risk exposure, or you consume a lot of fish and seafood, garlic is the way to go.
S-allylmercaptocysteine (SAMC), a sulfur compound in garlic, decreases the growth of cancer cells and causes the death of cancer cells in cell-based studies. SAMC binds to a protein involved in cell reproduction (tubulin) and disrupts cell growth, activating proteins (JNK1 and caspase-3) that cause tumor cell death [R, R, R].
10.Garlic May Help Treat Brain Cancer
Diallyl trisulfide, a sulfur-containing compound in garlic, decreases the size of brain tumors in mice by inhibiting the enzyme histone deacetylase (HDAC), which causes tumor cell death.
11.Garlic May Prevent Esophagus Cancer
Diallyl sulfide in garlic inhibits esophagus tumor formation in rats by disrupting the energy production of NMBA, which is a chemical found in fungi-contaminated foods that can cause liver and esophagus cancer.12.Garlic May Stop the Progression of Skin Cancer
Allyl sulfides in garlic control the growth of human skin cancer cells by causing DNA damage in cancer cells in human studies. The DNA damage in cancer cells signals the p53 protein to stop cancer cell growth and to kill cancer cells.
While garlic does have decent amounts of the minerals necessary for bone health, this is not its primary mechanism in promoting bone health. Rather, that is due to garlic’s pseudo-estrogen like effect on bone tissue, as was observed on post-menopausal women. Though more studies need to be performed to confirm its efficacy on preserving bone, it can’t hurt your to eat more of it in an effort to support your bone health.
14.Prevention Of Blood Clots
Blood clotting is intimately balanced to ensure that blood neither clots too much, or not enough. While both ends of the spectrum are bad, excessive clotting is particularly troublesome as it can lead to heart attacks and strokes without you ever knowing. You could be sitting fine one second, then a clot dislodges from its place of origin and travels to the brain or lungs and blocks an important small artery. Garlic consumption reduces the risk of experiencing a thromboembolic event, so try and consume or supplement with more garlic.
While eczema can have a broad range of causes, there appears to be one strong underlying similarity; immune dysfunction. This can be in the form of abnormal white blood cell function, suppression leading to increased infection or another disease with genetic lineage such as asthma. Eczema occurs more often in these individuals, and can be a very uncomfortable and annoying condition. Garlic consumption can reduce the frequency of rash eruption, promote healing and minimize the histamine response that causes you to itch. Adding it to your diet is a worthwhile move.