Allicin is a volatile compound that survives for just a few hours. It is a powerful natural antibiotic - about one-fiftieth as powerful as penicillin - and also has anti-fungal and anti-viral properties. Allicin exists only in raw garlic. Cooking kills it and causes it to decay into other compounds which are less effective.

Garlic also contains about ten different kinds of natural sugars, including fructose, glucose and insulin, as well as relatively high levels of the trace minerals copper, iron, zinc, tin, calcium, manganese, aluminium, germanium and selenium. The level of selenium in garlic is higher than in almost any other plant.

Garlic works inside the body by promoting the ability of white blood cells to fight infections, and by stimulating other immune cells which fight viral and bacterial infections as well as cancer.

Cholesterol
A multitude of medical studies confirm that garlic in several forms can reduce cholesterol. In the most recent study, using garlic pills and a placebo, researchers at Oxford University noted a 12 per cent reduction in total cholesterol.

Coronary artery disease is caused by a build-up of plaque within the arterial system. Studies have found that garlic appears to inhibiting new growth of plaque.

Pregnancy
Research from gynaecologists at the Chelsea and Westminster Hospital in London showed that taking garlic during pregnancy can cut the risk of pre- eclampsia, a potentially dangerous condition affecting one in ten pregnant women and causing raised blood pressure and protein in the urine.

Some studies also reveal that garlic may help to boost the birth-weight of babies destined to be too small.

Researchers found that taking standardised garlic tablets throughout pregnancy may decrease the chances of these types of complications at birth.

They found that adding extracts of garlic to the placental cells of women likely to suffer from these conditions stimulated growth.

In addition, the activity of key enzymes that are reduced in abnormal pregnancies where these conditions can occur were significantly increased when garlic was added.

Antiseptic
Garlic is the only antibiotic that can actually kill infecting bacteria and, at the same time, protect the body from the poisons that are causing the infection. In studies, garlic has been found to be almost as effective as penicillin, while recent research shows similar activity to a more modern antibiotic called chloramphenicol, used for typhoid fever as well as conjunctivitis.

Even the blood of people who eat garlic can kill bacteria, and it is also reported that the vapour from freshly-cut garlic can kill bacteria from a distance of 20cm.

In the past, garlic used to be used to treat tuberculosis, as the invading organism, mycobacterium tuberculosis, is sensitive to several of the sulphur components found in garlic.

Impotence
For centuries, garlic has been used by holistic healers as an aphrodisiac as it was thought to increase blood supply to the genitals.

However, more recent studies have found that an enzyme called nitric oxide synthase is primarily responsible for the mechanism of erection. Studies have recently shown that garlic can stimulate the production of nitric oxide synthase.

Cancer
There is a wealth of information published on the role of garlic in preventing cancer. Most research today is centred upon establishing which particular compounds, after allicin, are most active in inhibiting the growth of cancer cells.

Some very recent research from the U.S. proved that by injecting diallyl disulphide - formed when raw garlic is cut or crushed - into the bloodstream, tumours can be reduced by up to a half.

The research also found that another compound in garlic, called S-Allylcysteine, is effective in preventing cancer-causing agents from binding to human breast cells.

Other research found that increased garlic intake reduced nitrite levels in the body and resulted in fewer deaths from stomach cancer. It is also well known that garlic can help to strengthen the immune system, which is vitally important for fighting cancer.

Stomach ulcers
Modern medical studies have found that numerous diseases - gastric ulcers, ulcerative colitis, coronary artery disease, Kaposi's sarcoma and cervical cancer to name but a few - are triggered by infectious processes caused by bacteria or viruses. Garlic may be helpful in treating or preventing some of these conditions.

Recent discoveries by Australian scientists show that stomach ulcers are either caused by the helicobacter pylori bacteria, or contributed to by it, and that garlic can relieve ulcers as it kills this type of bacteria.

Other research has found that conditions such as Crohn's disease and ulcerative colitis may also be inflammatory diseases caused by or contributed to by the mycobacterium paratuberculosis bacteria, which again can be killed by eating raw garlic.

Blood clotting
Garlic is an anticoagulant and could be helpful in protecting against the blood clots which can cause strokes. If you are taking aspirin to keep your blood from forming clots, garlic may be a more pleasant and natural alternative.

Mixing aspirin or other blood-thinning medicines with garlic can be dangerous under some circumstances though. Always consult your GP before taking garlic supplements in conjunction with medications for blood thinning.

Digestion
Allicin promotes the secretion of gastric juices by stimulating the mucous membranes of the stomach. It also combines with the stomach's natural proteins, reducing the excessive activity which can lead to indigestion.