Garlic is a great antioxidant and makes good soups etc.
But eating raw garlic and too much of it can cause bad breath, burning sensation in your mouth or tongue, body odor, diarrhea, nausea, heartburn and gas in your stomach.
Eating way too much garlic can also increase your risk of developing stomach ulcers and could cause stomach or other internal bleeding.
Eating garlic in moderation though is pretty healthy for you but just avoid eating too much garlic and you'll be fine.