Is garlic really good for the heart, and if so why?

If you fear a clot in your coronary arteries – a coronary thrombosis – then enzymes in it (thiosulphinate and allicin) help prevent clots forming. Cooking it for more than five minutes destroys them. You have to crush it first (to break down cell walls) to make the enzymes available for digestion. So eat nearly raw crushed garlic to get the best out of it.