Garlic has been used for thousands of years for medicinal purposes. To our knowledge, the earliest scientific studies exploring the benefits of garlic began in the 1950s. Since then, thousands of research studies have been published based on garlic’s effectiveness and safety through animal and human studies.
This powerful natural antibiotic can be found in the National Library of Medicine with 4,252 studies, showing it can effectively treat more than 150 chronic diseases, including heart disease.
While this research is promising, atherosclerosis-related diseases (ARDs) such as ischemic heart disease (IHD), stroke, and peripheral vascular disease remain the leading global cause of death. To address this, we saw the importance of developing a safe, affordable, and accessible strategy for preventing heart-related diseases. To our knowledge, no studies were investigating the important benefits of garlic supplementation for these serious cardiovascular conditions.
To better understand garlic benefit for ARDs, we reviewed literature reviews investigating the effect on endpoints such as infarction, stroke, percutaneous interventions, or death. Thus, we summarized the evidence for the use of garlic in treating traditional clinical risk factors based on the Framingham risk score, namely, hypertension and total cholesterol (TC).
We reviewed science journals through May of 2013, investigating the effects of garlic supplements on hypertension, hypercholesterolemia, C-reactive protein (CRP), pulse wave velocity (PWV), and coronary artery calcium (CAC), as well as available data on side effects.
Reviewing the scientific journals gave us a better understanding of garlic’s impact on ARDs from a doctor’s perspective.
The methods by which we chose to conduct this study had these qualifications: 1) one or more of these terms in their heading: “garlic,” along with one or more of the words “hypertension,” “hypercholesterolemia,” “C-reactive protein,” and “arterial occlusive diseases”; 2) double-blind, randomized, controlled trials and meta-analyses of double-blind, randomized, controlled trials were included; 3) following criteria was approved by both authors: a) cohort or double-blind, b) specified garlic dose c) relevant data approved by both authors.
Antihypertensive therapy is associated with a 20 – 25% relative risk reduction in ischemic heart disease (IHD) and a 30 – 40% reduction in stroke. This concluded that 50% of hypertensive patients could be using garlic as an adjunct or solely for treatment.
We focused our studies on four meta-analyses and two original reviews published since then. In one study, garlic did lower SBP and DBP in hypertensive patients, but not in normotensive patients. In the second meta-analysis study, they found a significant association between blood pressure at the start of the research and reduced blood pressure. The third study reviewed trials related to the effects of garlic on hypertension and could not be recommended given the “low methodological quality.” The final analysis concluded that treatment with garlic decreases SBP by 10–12 mm Hg and DBP by 6–9 mm Hg.
Kyolic brand garlic powder (KB AGE) was used in all three studies enrolling hypertensive patients. These patients were found to have a significant decrease in systolic blood pressure (SBP) of 16.3 mm Hg (95% CI: 6.2, 26.5) and diastolic blood pressure (DBP) of 9.3 mm Hg (95% CI: 5.3, 13.3) compared with the placebo.
Based on our literature review, we identified a few studies with a methodologic quality that showed a favorable effect on blood pressure from garlic preparations in the range of 7–16 mm Hg for SBP and 5–9 mm Hg for DBP. In comparison, the placebo only saw this in patients with hypertension at their baseline. In addition to this, reduced blood pressure by 40% with IHD events.
According to the 2010 American College of Cardiology Foundation/AHA Guideline for Cardiovascular Disease Risk in Asymptomatic Adults, coronary artery calcium (CAC) can additively help risk-stratify patients into low or high risk, but also, being a validated prognostic marker of IHD and can additively help patients at intermediate risk based on Framingham risk factors. Furthermore, CAC measurements can help predict patients’ risks further, and it is becoming an acceptable surrogate endpoint. Moreover, treatment with statins has been shown to reduce the rate of CAC progression while showing a CAC score progression of >15% per year significantly increases mortality.
Through the study, we monitored 23 patients with known CAD or high-risk patients for over one year, with KB AGE, which reduced CAC progression compared with placebo. Similarly, this showed significant results in 65 intermediate-risk patients with a Framingham risk of 10–20% and baseline CAC >30. Through this study, KB AGE was administered with vitamin B-12, folic acid, vitamin B-6, and L-arginine. Over a one year duration, the CAC progression was significantly lower in the treatment group than in the placebo group (6.8% compared with 26.5%, P = 0.005).
From this discovery, CAC progression is associated with a greater risk of IHD. Based on these three small scale studies, garlic supplementation shows a decrease in CAC progression rate. This can be hypothesized that garlic may decrease rates of IHD. Although all three reviews used KB AGE, it should note that two studies used additional treatments along with KB AGE, which may have influenced the results.
No studies showed effects on death, heart attack, or stroke, but blood pressure reduced and IHD reduced by up to 40%. Other studies showed that 23 patients with known coronary artery disease (CAD) or high-risk patients reduced their CAC risk within one year of garlic supplementation. Since CAC progression is associated with a greater risk of IHD, it can hypothesize that garlic supplementation decreases this rate.
Following this study, we enrolled 80 individuals in a single-center, randomized, placebo-controlled, double-blind trial conducted at the Lundquist Institute for Biomedical Innovation Harbor-UCLA Medical Center. Through this study, we investigated whether Kyolic Aged Garlic Extract (KB AGE) reduces coronary plaque volume measured by cardiac computed tomography angiography (CCTA) in patients with diabetes mellitus (DM). The purpose of this study was to evaluate the effect of Aged Garlic Extract over a year on the coronary atherosclerotic plaque in individuals with T2DM utilizing CCTA.
Wakunaga of America provided daily doseage of 2,400 mg of Kyolic Aged Garlic Extract with a matched placebo pill. All participants were advised to take two capsules twice daily with water for one year. By percentage, there was a 29% reduction in low-attenuation plaque (LAP) in the group on Aged Garlic Extract instead of 57% LAP plaque progression in the placebo group.
Through this study, the Aged Garlic Extract group showed a reduction in fibro fatty plaque compared to the progression of FF in the placebo group. However, it did not reach statistical significance, and there were no differences observed in TP, fibrous, or fibro-fatty plaque volumes between the Aged Garlic Extract and placebo group.
Over the one year duration of Aged Garlic Extract therapy, we discovered it was associated with regression of low attenuation plaque. Low attenuation plaque is one of the high risk plaque features. Our results are in concordance with several previously published reports of low attenuation plaque regression in participants with metabolic syndrome and general population in studies of Aged Garlic Extract and statin studies.
Kyolic Aged Garlic Extract is sourced in California’s central valley, under strictly controlled conditions without chemical fertilizers, herbicides, or pesticides. When fully mature, the garlic is harvested, cleaned and sliced before being placed in specialized stainless steel containers where it is aged, without heat, for up to 20 months.
This proprietary process increases the garlic’s antioxidant potential and converts harsh and unstable organosulfur compounds into the odorless, non-irritating, and bioavailable compounds responsible for Kyolic’s numerous health benefits.
Previous studies demonstrated an increased risk of myocardial infarction and cardiovascular death in patients with a larger volume of non-calcified and low-attenuation plaque. With the study, we discovered a 57% increase in LAP in the placebo group, representing the natural history of the plaque progression. On the contrary, we noticed a 29% reduction of LAP in Aged Garlic Extract users within one year. We concluded the benefits of therapeutic potential of Aged Garlic Extract within the diabetic population.
Garlic is generally safe with mild gastrointestinal discomfort as the most common intolerability, but even GI discomfort can be avoided using Aged Garlic Extract. But our study did have several limitations including a small sample size that did not have conclusive evidence on the significant differences in TPV, NCP, and DC. Also, patients were under different therapies for hyperlipidemia and T2DM, and some patients used varying medications and different doses.
Why is Aged Garlic Extract important to heart health? Garlic is supported by thousands of years of clinical use and multiple small-scale studies showing favorable effects without significant side effects or cost, so it appears, based on current research and results, that it is worthwhile to pursue garlic therapy for heart health further.
Dr. Matthew Jay Budoff, MD, FACC, FAHA, is a professor of medicine at David Geffen School of Medicine at UCLA and the endowed chair of preventive cardiology at the Lundquist Institute at Harbor-UCLA Medical Center and the endowed chair of preventive cardiology at the Lundquist Institute in Torrance CA. Budoff is a graduate of University of California at Riverside (BS) and graduated a member of Alpha Omega Alpha from George Washington University School of Medicine (MD). He completed his training in internal medicine and his cardiology fellowship at Harbor-UCLA Medical Center. Budoff is on the editorial boards of several cardiology journals, including Clinical Cardiology, Journal of Invasive Cardiology, JACC: Cardiovascular Imaging, and Cardiovascular Diabetology. Budoff has authored or coauthored more than 50 books and book chapters and more than 2,000 articles and abstracts. He has received numerous research grants from the National Institutes of Health and has been invited to lecture at cardiology conferences around the world. In addition to his 2015 appointment as the Endowed Chair of Preventive Cardiology at Harbor-UCLA Medical Center, he has been recognized for his work by the Society of Cardiovascular Computed Tomography, from which he received the Gold Medal Award and recently designated as Master of the Society of Cardiovascular Computed Tomography (MSCCT), and has been inducted into the European Academy of Sciences. Budoff has been named to “America’s Top Doctors” for each of the past nine years. In 2011, he was named a U.S. News & World Report Top Doctor for cardiology, was awarded the Albert Nelson Marquis Lifetime Achievement Award in 2018 and named “The world’s most influential scientific researchers” in 2018 and 2019.