Garlic contains allicin, a naturally occurring antioxidant that may help improve heart health. Compounds in garlic also act as powerful antioxidants. There is some evidence that garlic may lower blood pressure and LDL-cholesterol levels — as well as decrease levels of homocysteine — a by-product of protein breakdown that causes inflammation and damages blood vessels.
Although most of the studies that support the health benefits of garlic are done with garlic supplements, they certainly encourage the continued use of garlic as a delicious flavor enhancer in everyday food. Because garlic can act as a blood thinner, it’s important for you to check with your doctor before adding large amounts of garlic to your diet if you take any blood-thinning medications (such as Warfarin) or aspirin.
If bad breath (also known as halitosis) is a problem for you, cutting down on garlic and onions may help. These Allium vegetables contain smelly compounds that get absorbed into your bloodstream and exhaled from your lungs for hours after you eat them.
People who suffer from IBS (Irritable bowel syndrome) should be careful about eating onions and garlic, as they are common IBS trigger foods and may lead to discomfort after eating them. Raw garlic, in particular, can be difficult for some people to tolerate, especially if IBS is an issue; so if you have a sensitive stomach it’s probably best to add garlic only during cooking.