The notion that food items could slow or even reverse atherosclerosis of heart arteries, one of the most serious health threats in the Western world, was considered unlikely until demonstrated by the LifeStyle Heart Trial decades ago (http://www.ncbi.nlm.nih.gov/pubmed/9863851). The emphasis on plant based nutrition without added oils has been confirmed as effective for reversing heart disease in other centers (http://www.ncbi.nlm.nih.gov/pubmed/25198208) and has been approved by Medicare as a covered therapy. However it is unclear if specific components of a whole food plant based diet accelerate the reversal process. For more than a decade, garlic has been in the spotlight as having the potential to impact coronary atherosclerosis favorably. But is there data?
A dozen years ago the rate of increase in coronary artery calcium scoring, a marker for atherosclerosis, was measured in subjects taking an aged garlic product or placebo (http://www.ncbi.nlm.nih.gov/pubmed/15475033). The mean change of the calcium score was significantly lower in subjects taking the active garlic product along with a trend towards improved high density lipoprotein cholesterol levels and homocysteine levels.
Since then, studies using coronary CT angiography, a more advanced imaging modality, have been completed (http://www.ncbi.nlm.nih.gov/pubmed/26764322). Over the course of a year, subjects consuming aged garlic extract experienced a significantly lower change in plaque compared to subjects taking a placebo. Using a different vascular assessment, the carotid intimal-media thickness (CIMT) test, a group of subjects taking garlic powder tablets or placebo were studied (http://www.ncbi.nlm.nih.gov/pubmed/25573347). After 3 months of treatment, CIMT differences existed with superior prevention of progression in the garlic group.
The mechanism by which garlic may prevent progression of atherosclerosis has been studied. The inflammatory marker C-reactive protein was lower after garlic and CoQ10 therapy than with placebo after 1 year of therapy (http://www.ncbi.nlm.nih.gov/pubmed/22923934). In another investigation, aged garlic extract reduced peripheral and central blood pressure while improving arterial stiffness and inflammation (http://www.ncbi.nlm.nih.gov/pubmed/26869811).
While a complete immersion into a whole food plant based diet is supported by scientific studies for the reversal of atherosclerosis, not all persons with this condition are willing to adopt this dietary pattern. Aged garlic is inexpensive and very well tolerated. The weight of the scientific evidence supports it use in a more widespread manner.