Garlic is one of the most common cooking ingredients around the world. Many dishes in Europe, Africa, Asia and the Americas use this strong-flavored vegetable. Garlic is similar to other bulb-shaped plants, including onions, chives, leeks and scallions. But garlic is special. For centuries, people have used garlic not only for cooking, but also for medicine.

For example, in ancient Greece and Rome, people considered garlic an aid to strength and endurance. The original Olympic athletes in Greece ate garlic to improve their performance. The ancient Romans fed garlic to the soldiers and sailors. Workers who built the pyramids in Egypt ate garlic. In fact, this is a theme throughout early history -- workers eating garlic to increase their strength.

But why is garlic such a healthy food? The short answer is that garlic creates a gas called hydrogen sulfide. At first, hydrogen sulfide does not seem very healthy. In fact, it is toxic and flammable. It smells like rotten eggs. But it does an important job in our bodies. Hydrogen sulfide relaxes blood vessels. Relaxing blood vessels, in turn, allows more oxygen to travel to the body's organs. It lowers high blood pressure and protects the body against cardiovascular disease.

Also, to get the full effect of garlic's health benefits, do not add it to food or cook with it immediately. Cutting, crushing or mincing garlic releases the healthy compound found in the vegetable. But heating the garlic or adding it to other ingredients prevents the release of this healthy compound. So cut or crush or mince the garlic, and let it rest by itself for a couple minutes.