A recent study published in Maturitas science journal indicates that aged garlic extract lowers blood pressure in patients with treated, but uncontrolled, hypertension.

The study examines 50 adult patients with uncontrolled hypertension currently taking conventional antihypertensive medications.  Individuals were selected from two general practices in metropolitan Adelaide, South Australia.  Those patients with unstable medical conditions or other serious illnesses, such as dementia, terminal illness and pregnancy, were excluded from the study.  Because a majority of the patients suffered from high systolic blood pressure (SBP), the research team stratified the patients according to subgroups.  The patients were separated according to SBP: uncontrolled baseline SBP (>140 mm HG) and controlled baseline SBP (<140 mm HG).

For 12 weeks, 25 patients were assigned four capsules daily of name-brand supplement Kyolic, which contains 960 mg of aged garlic extract and 2.4 mg of Sallylcysteine (SAC).  One capsule is equivalent to approximately 2.5 g of fresh garlic.  The rest of the 25 patients were allocated placebo capsules for 12 weeks as well.  The research results indicate that aged garlic extract is superior to placebo in lowering SBP especially in patients with treated, but uncontrolled, blood pressure.  Initially, the mean SBP for the subgroup with uncontrolled SBP allocated garlic capsules was 151.2 mm HG.  By the final week of the study, the mean SBP for the subgroup had dramatically dropped to 136 mm HG. 

In contrast, for individuals with controlled SBP, no significant decrease in SBP was found.  For individuals with controlled SBP exposed to aged garlic extract, 128 mm HG was the initial mean baseline SBP.  By the end of the study, the mean had increased to 132.4 mm HG. The increase does not indicate the negative effects of aged garlic extract, but rather indicates the threshold level of the supplement.  As a trend, aged garlic extract affects patients with SBP over 140 mm HG.  Patients with SBP below this level cannot expect significant results from the supplement.  


Published in WholeFoods Magazine, November 2010 (ahead of print on September 23, 2010)