Garlic is classified as both a food and medicinal herb. It can and should be eaten as food, but it can also be taken in supplement form to augment a healthy diet when more serious health problems arise. Here's how this alternative medicine works:
Garlic has many healing properties, but the most research has been done on its potential to help reduce heart disease. Garlic has been intensively studied, and numerous large studies have shown that taking supplements that mimic fresh garlic can significantly lower LDL cholesterol levels without hurting beneficial HDL cholesterol levels. Garlic appears to act by blocking the liver from making too much LDL cholesterol.
There is also some evidence that garlic supplements can mildly lower blood pressure by dilating or expanding blood vessels. And garlic helps prevent blood clots -- and therefore reduces the risk of heart attack and stroke -- by decreasing the stickiness of platelets, which are tiny disk-shaped bodies in the blood that are necessary for blood clotting. When platelets are too sticky, they form clumps that can adhere to artery walls and contribute to clogged arteries.
Garlic has also been shown to reduce pain and other symptoms in people with rheumatoid arthritis. And it reduces the size of some cancerous tumors and helps prevent some cancers, particularly those in the intestines. However, the research on this is not nearly as far advanced as that for garlic and heart disease, so do not use garlic supplements without consulting with a natural health care professional.
One of the oldest uses of garlic, however, is as an antibiotic. Garlic kills a range of microbes, including viruses, bacteria, fungi, and parasites, and can be effective against such conditions as athlete's foot, thrush (a fungal infection of the mouth), viral diarrhea, and the ulcer-causing bacteria Helicobacter pylori. Only fresh garlic or supplements that mimic it have these effects.