When you make tomato sauce, you probably put the garlic in the hot oil right after you have chopped ir. Well, it is wrong!
If you put the chopped garlic in the hot oil right away, you are entering none allicin in your organism. Allicin is the compound that makes this vegetable so healthy.
The enzyme that produces allicin is not activated until you peel garlic, and when it comes into contact with heat it is quickly destroyed, in fact, it is totally destroyed in just a minute in hot oil.
If you want to enter allicin in your body, leave the chopped garlic lying on the cutting board for ten minutes, before you put it in hot oil. It is better to mash the garlic rather than chop it.