Garlic reduces TC to a modest extent , an effect driven mostly by the modest reductions in TAG , without appreciable LDL lowering or HDL elevation .
Higher baseline line TC levels and the use of dietary modification may alter the effect of garlic on these parameters .
In order to determine the impact of  garlic on total cholesterol ( TC ) , TAG levels , as well as LDL and HDL  , and establish if any variables have an impact on the magnitude of this effect , a meta- analysis was conducted .
Garlic powder and plasma lipids and lipoproteins: a multicenter, randomized, placebo-controlled trial.
BACKGROUND Garlic powder tablets have been reported to lower  serum cholesterol levels .  There is widespread belief among the general public that garlic powder tablets aid in controlling cholesterol levels . However , much of the prior data demonstrating the cholesterol-lowering effect of garlic tablets involved studies that were inadequately controlled . OBJECTIVE To determine the lipid-lowering effect of garlic powder tablets in patients with hypercholesterolemia .  METHODS This was a r and omized , double-blind , placebo-controlled , 12-week , parallel treatment study carried out in 2 outpatient lipid clinics . Entry into the study after 8 weeks of diet stabilization required a mean low-density lipoprotein cholesterol level on 2 visits of 4.1 mmol/L ( 160 mg/dL ) or lower and a triglyceride level of 4.0 mmol/L ( 350 mg/dL ) or lower . The active treatment arm received tablets containing 300 mg of garlic powder ( Kwai ) 3 times per day , given with meals ( total , 900 mg/d ) . This is equivalent to approximately 2.7 g or approximately 1 clove of fresh garlic per day . The placebo arm received an identical-looking tablet , also given 3 times per day with meals . The main outcome measures included levels of total cholesterol , triglycerides , low-density lipoprotein cholesterol , and high-density lipoprotein cholesterol after 12 weeks of treatment . RESULTS Twenty-eight patients ( 43 % male ; mean + /- SD age , 58 + /- 14 years ) received garlic powder treatment and 22 ( 68 % male ; mean + /- SD age , 57 + /- 13 years ) received placebo treatment . There were no significant lipid or lipoprotein changes in either the placebo- or garlic-treated groups and no significant difference between changes in the placebo-treated group compared with changes in the garlic-treated patients . CONCLUSION Garlic powder ( 900 mg/d ) treatment for 12 weeks was ineffective in lowering cholesterol levels in patients with hypercholesterolemia
Garlic reduces TC to a modest extent , an effect driven mostly by the modest reductions in TAG , without appreciable LDL lowering or HDL elevation .
Higher baseline line TC levels and the use of dietary modification may alter the effect of garlic on these parameters .
In order to determine the impact of  garlic on total cholesterol ( TC ) , TAG levels , as well as LDL and HDL  , and establish if any variables have an impact on the magnitude of this effect , a meta- analysis was conducted .