PROTECTIVE EFFECT OF CHRONIC GARLIC INTAKE ON ELASTIC PROPERTIES OF AORTA IN THE ELDERLY

Background Epidemiological studies have suggested that garlic may have protective effects against cardiovascular diseases. We undertook this cross-sectional observational study to test the hypothesis that regul ar garlic intake would delay the stiffening of the aorta relating to a ging. Methods and Results We studied healthy adults (n=101; age, 50 to 80 years) who were taking greater than or equal to 300 mg/d of standa rdized garlic powder for greater than or equal to 2 years and 101 age- and sex-matched control subjects. Pulse wave velocity (PWV) and pressu re-standardized elastic vascular resistance (EVR) were used to measure the elastic properties of the aorta. Blood pressures, heart rate, and plasma lipid levels were similar in the two groups. PWV (8.3+/-1.46 v ersus 9.8+/-2.45 m/s; P<.0001) and EVR (0.63+/-0.21 versus 0.9+/-0.44 m(2) . s(-2) . mm Hg-1; P<.0001) were lower in the garlic group than i n the control group. PWV showed significant positive correlation with age (garlic group, r=.44; control group, r=.52) and systolic blood pre ssure (SBP) (garlic group, r=.48; control group, r =.54). With any deg ree of increase in age or SBP, PWV increased less in the garlic group than in the control group (P<.0001). ANCOVA and multiple regression an alyses demonstrated that age and SBP were the most important determina nts of PWV and that the effect of garlic on PWV was independent of con founding factors. Conclusions Chronic garlic powder intake attenuated age-related increases in aortic stiffness. These data strongly support the hypothesis that garlic intake had a protective effect on the elas tic properties of the aorta related to aging in humans.