Garlic actually may be effective in slowing the development of atherosclerosis and seems to be able to modestly reduce blood pressure.

http://www.webmd.com/vitamins-supplements/ingredientmono-300-garlic.aspx?activeingredientid=300&activeingredientname=garlic

Garlic is used for many conditions related to the heart and blood system. These conditions include high blood pressure, high cholesterol, coronary heart disease,heart attack, and “hardening of the arteries” (atherosclerosis). Some of these uses are supported by science. Garlic actually may be effective in slowing the development of atherosclerosis and seems to be able to modestly reduce blood pressure.