The notion that foods 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. The emphasis on plant based nutrition without added oils has been confirmed as effective for reversing heart disease in other centers and has been approved by Medicare as a covered therapy.
It is unclear if specific components of a whole food plant 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.
The rate of increase in coronary artery calcium scoring, a marker for atherosclerosis measured by CT, was assessed in subjects taking an aged garlic product or placebo. 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, even more hopeful studies of the role of aged garlic have been performed using coronary CT angiography, a more advanced imaging modality. 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. After 3 months of treatment, CIMT differences existed with superior prevention of progression in the garlic group.
Finally, in a recent randomized analysis of the impact of a year of therapy of aged garlic on epicardial adipose tissue measured by CT, a surrogate for coronary artery progression, patients treated with the active compound had less progression than those assigned to placebo tablets.
The mechanism by which garlic may prevent progression of atherosclerosis has been studied. In one study, the inflammatory marker C-reactive protein was lower after garlic and CoQ10 therapy than with placebo after 1 year of therapy. In another investigation, aged garlic extract reduced peripheral and central blood pressure while improving arterial stiffness and inflammation. Recently, a 12 week study of aged garlic in uncontrolled hypertensives proved effective versus placebo in terms of blood pressure reduction, reduced markers of inflammation, and favorable changes in microbiome species.
In a study of aged garlic versus fresh garlic, aged garlic was superior in terms of both antioxidant and antimicrobial activity. In 51 healthy but obese study subjects, 6 weeks of aged garlic extract provided superior levels of LDL cholesterol and inflammatory markers like IL-6 and TNF-alpha versus placebo.
While a complete immersion into a whole food plant diet is supported by scientific studies for the reversal of atherosclerosis, not all persons with this condition are willing to completely adopt this dietary pattern. Aged garlic is inexpensive and very well tolerated. The weight of the scientific evidence supports using aged garlic in a more widespread manner in patients with hypertension, hyperlipidemia, inflammation, and coronary atherosclerosis.