Garlic supplements definitely lower blood pressure and decrease the risk of dying from a heart attack
To provide an updated perspective, Dr. Ried and her team included more recently published studies in their analysis, identifying 11 studies in which the patients were randomly assigned to garlic or placebo. In most studies, participants given garlic took it in capsule-powdered form. Doses ranged from 600 mg to 900 mg daily, which study participants took for 12 to 23 weeks.
When the researchers pooled the data from the trials, they found that garlic reduced systolic blood pressure (the top number in a blood pressure reading) by 8.4 mm Hg on average in people with high blood pressure, and reduced diastolic blood pressure (the bottom number) by 7.3 mm Hg. The higher a person's blood pressure was at the beginning of the study, the more it was reduced by taking garlic; garlic became increasingly more effective in those with more elevated blood pressure. These results mirror the effects on blood pressure reduction achieved through the use of beta-blocker drugs and also by ACE inhibiting drugs and the amount lowered by garlic can decrease the risk of developing heart disease or dying from a heart attack by a considerable 20%. The study was published online ahead of print in the journal BMC Cardiovascular Disorders.