Garlic is a very popular natural treatment for high blood pressure. It
appears from a 2005 study that using fresh garlic in your diet may be
more effective than using supplemental forms.
Allicin, the active ingredient in garlic . . .is destroyed within
one hour of smashing the garlic. This means that garlic pills are
virtually worthless and should not be used.
Instead, when you use the garlic, compress it with a spoon prior to
swallowing it, or put it through your juicer to add to vegetable
juice. Just be careful not to put too much as raw garlic has a
powerful flavor and can cause some unpleasant surprises.