For centuries garlic has been used as a medicinal and culinary substance in India, China, Greece and other countries. It has been used as a salve for everything from headaches to colds to infections and healing wounds.

Garlic does not make significant nutritional contribution to the diet because the quantities added to recipes are small. But even these nano amounts make a big difference to one's health.

The biological benefits and the distinct odour of garlic are attributed to the many sulphur containing compounds; one of which is Alliin. This compound is converted to Allicin when garlic is crushed. Allicin is, perhaps, the principal bioactive compound present even in processed garlic.

Limited evidence supports an association between garlic consumption and a reduced risk of colon, prostate, oesophageal, larynx, oral, ovary and other cancers. This is due to diallylsulde, a potent bioactive component. Besides, the plant can also accumulate selenium, a trace element known to possess anti-cancer properties, from the soil.

Curtailing cardiac diseases

One inexpensive way of curtailing cardiovascular diseases is to use generous amounts of garlic in cooking. Garlic consumption inhibits the progression of cardiovascular diseases. It can bring about small reductions in blood pressure. Some studies have shown it to modestly lower cholesterol levels, which is also a protection against cardiac diseases. Animal experiments have associated garlic ingestion with reduction in triglyceride and LDL cholesterol, both of which contribute to atherosclerosis and heart diseases. Garlic, like aspirin, can reduce the tendency of blood to coagulate and form clots. Many human studies on garlic have shown it has the ability to dissolve blood clots. Pharmaceutical supplements are often used by patients with cardiac and vascular diseases.

Garlic can reduce homocysteine levels in blood. This toxic compound damages the cells that line the blood vessels, induces blood clots, loss of cognition and causes death of nerve cells. People with dementia and Alzheimer's disease have elevated blood homocysteine levels. Damage to nerve cells in Alzheimer's disease is also due to elevated oxidative stress induced by free radicals. By scavenging free radicals, garlic offers protection from neuronal death, dementia and Alzheimer's disease.