Why garlic is good for health

23 October, 2007

For centuries, garlic has been believed to be good for health, especially on account of its anti-bacterial and anti-fungal properties as well as the beneficial effects on the cardiovascular system.

Researchers at the University of Alabama at Birmingham in the United States now say that they have found out precisely why garlic makes such a valuable health tonic. Garlic enhances the body’s own production of a compound that relaxes blood vessels, increases blood flow, and prevents blood clots and oxidative damage.

Much of the research into the pharmacological benefits of garlic has focused on the organic polysulphides that the clove is rich in, the best known of which is allicin.

But the new research suggests that allicin and similar biologically active compounds are only a part of the positive effects of garlic and that it is the chemical messenger that is produced when these compounds are metabolised that is important.

Allicin stimulates the release of hydrogen sulfide from red blood cells. Though this compound is lethal in large doses, in minute doses it relaxes the blood vessels and promotes smooth flow of blood, the researchers said.

In a purely laboratory-based experiment, researchers bathed the blood vessels of laboratory mice in a bath containing crushed garlic juice. They found that the tension within these blood vessels was reduced by as much as 72%.

They also found that garlic juice was able to stimulate red blood cells to release hydrogen sulphide. Hydrogen sulphide at low concentrations is also useful in cell-to-cell communication.

Garlic relaxes the blood vessels, promoting easier blood flow within them. This, in turn, brings down the blood pressure and lowers the load on the heart.

David Kraus, senior researcher at the University of Alabama, Birmingham, said that earlier studies had failed to produce uniform results mainly because of the way garlic was prepared. He explained: “If you prepare it in certain ways, you can lose the compounds that cause it to release hydrogen sulfide, so that helps explain why there has been such great variability in studies.”

Garlic, or allium sativum, is one of the most-studies herbs in relation to heart benefits.

According to the United States National Center for Complementary and Alternative Medicine, garlic is also used to prevent certain types of cancer, including stomach and colon cancers, but there is no scientific evidence to support this theory. Garlic might also be used in preventing the development of arteriosclerosis, which hardens arteries and is the first step in the development of heart disease.

However, garlic must be used with caution in people who have a bleeding disorder, because it is a powerful blood thinner. Other side-effects of garlic include bad breath, body odor, heartburn, upset stomach, and allergic reactions.