Some studies say one thing, some say another. Standardized doses make it easier to track the effectiveness, but there are questions as to the effectiveness of garlic at all after it's been tampered with. The reasoning is that the power as well as the taste and odor of garlic is released when a clove is bruised, cut or chewed. Allicin thus released oxidizes quickly and breaks down into over a hundred different substances, not all of which are proved to be helpful to the human body. It's best to go with what we know to be true.
Raw garlic is an antibiotic, taken internally or externally.
It lowers blood pressure in pill form. It's an anticoagulant in any form. It inhibits the growth of cancers and tumors in raw form. With all the benefits to the average person, it should be included in every other diet every day. Especially in the US, where overweight, high blood pressure and heart problems are common health concerns, a daily dose of garlic is a part of a sensible, healthy diet.