Life Extension Magazine®
Since the 1950s, scientists have been researching garlic, with particular focus on heart health.1
Garlic has been shown to help reduce heart disease risk factors, including atherosclerosis, elevated cholesterol, thrombosis, and high blood pressure.1-3
For those seeking these broad-range cardiovascular benefits, aged garlic extract is the best validated form from a clinical study perspective.
What you need to know
- Garlic’s health benefits have been recognized for thousands of years.
- Garlic has numerous cardioprotective effects, including preventing or improving atherosclerosis, high cholesterol, and high blood pressure.
- Aged garlic extract contains unique and potent compounds—including S-allylcysteine—that fight oxidative stress.
- Published studies reveal marked reductions in a range of vascular disease risk factors.
Broad Cardioprotective Effects
Garlic is high in unique sulfur compounds that are responsible for its scent, taste, and beneficial effects—including its broad benefits for heart health.
An exhaustive 2016 review published in the Journal of Nutrition cited heart benefits seen with garlic supplementation, including:1
- A reduction in systolic blood pressure of 7-16 mmHg,
- A reduction in diastolic blood pressure of 5-9 mmHg,
- A decrease in total cholesterol of 7.4-29.8 mg/dL
- Favorable effects on reducing the progression rates of coronary artery calcium (calcium deposits in the coronary arteries, which is indicative of atherosclerotic plaque),
- Improved pulse wave velocity (a measure of arterial stiffness),
- Reduced C-reactive protein (higher levels of which indicate inflammation), and
- Overall general safety.
Aged Garlic Extract, a Potent Form of Garlic
Many different forms of garlic preparations are used for supplementation, but research on aged garlic extract stands out.
The long-term aging of garlic in diluted alcohol, without heat, produces unique and potent compounds—including S-allylcysteine and other S-allyl compounds. These sulfur-based constituents have powerful oxidant-reducing qualities. A number of other beneficial compounds may also be produced by the aging process.4,5
Adding to the collective findings of the 2016 review, newer studies on the cardioprotective effects of aged garlic extract have revealed remarkable results.
One of the most compelling effects of aged garlic extract is its ability to help reverse early heart disease. It accomplishes this by stripping deadly plaque buildup from artery walls.
In a randomized, double-blind study, researchers gave metabolic syndrome patients (aged 40 to 75) either a placebo or 2,400 mg of aged garlic extract daily. Then they assessed their coronary arteries—those that supply blood to the heart—for plaque.6
Follow-up screening a year later showed that those taking the garlic experienced slower accumulation of total plaque compared to the placebo group. More impressively, there was a regression of “low-attenuation” plaque.6
Low-attenuation plaque is soft plaque. Reducing this type of plaque has a significant stabilizing effect on atherosclerosis.
This ability to inhibit—and even reverse—arterial plaque buildup constitutes a critical reduction in the risk of atherosclerosis.
Anti-Inflammatory Benefits
Chronic inflammation plays a role in the formation and progression of atherosclerotic plaques.
Aged garlic extract has been shown to inhibit inflammation.7
A 2017 study gave aged garlic extract to highly atherosclerosis-susceptible mice for 12 weeks.
Mice receiving aged garlic extract experienced the following reduction in heart attack risk factors compared to control mice that did not receive aged garlic extract:7
- C-reactive protein (CRP) by 39%,
- Tumor necrosis factor alpha (TNF-alpha) in the liver by 35%,
- Thromboxane B2 (TXB2) by 33%, and
- Interleukin-1 receptor-associated kinase 4 (IRAK4) by 60%.
The study author described these results as an “anti-atherosclerotic effect.”7
Similar anti-atherosclerotic effects have been demonstrated in humans as well.8
For example, scientists set out to assess the effects of aged garlic extract on adipose (fat) tissue in humans. Increased adipose tissue is seen as a marker for atherosclerosis progression and is associated with the severity of coronary artery calcium.8
In this randomized, placebo-controlled trial, 60 volunteers were given either a placebo or aged garlic extract (combined with arginine, folate, and vitamins B6 and B12). After one year, the group taking the aged garlic extract had reduced their growth rates of several types of adipose tissue.8
Reduced Cholesterol Levels
Elevated cholesterol levels are a factor in plaque buildup. In a 2018 study, aged garlic extract exhibited beneficial effects on cholesterol and inflammation levels.9
The researchers divided 51 obese participants into two groups: One took a divided daily dose of 3,600 mg of aged garlic extract and the other took a placebo.
After six weeks, the aged garlic extract reduced blood LDL (bad) cholesterol. It also modified the secretion of inflammatory proteins, indicating that the extract may help prevent chronic diseases associated with low-grade inflammation—such as cardiovascular disease.9
Lower Blood Pressure
Aged garlic extract has been shown to reduce blood pressure in both lab studies and in humans.10,11
One team of scientists found that aged garlic extract was able to relax aortic tissue in rats by increasing production of nitric oxide,10 a compound known to dilate blood vessels and lower blood pressure.12
Another 2017 study involved a comprehensive review of nutraceuticals that have “clinically detectable,” blood pressure-lowering effects. According to this review, compounds in aged garlic extract known as polysulfides—the compound S-allylcysteine, in particular—enhanced the regulation of nitric oxide, which in turn induces smooth muscle-cell relaxation, vasodilation, and blood pressure reduction.11
The study author concluded that “a relatively large body of evidence” supports the use of aged garlic extract to lower blood pressure.11
Also, a review and meta-analysis published in the Journal of Nutrition assessed numerous randomized, controlled, human trials over a 58-year period to determine garlic’s capacity to lower both cholesterol and blood pressure.13
The researchers found that aged garlic extract reduced systolic blood pressure by an average 4.1 mmHg.
But in the participants who had high blood pressure, garlic extracts provided a larger decrease in blood pressure—an average reduction of 8.7 mmHg in the systolic and 6.1 mmHg in the diastolic reading.13
This indicates that garlic extracts work best in those who need it most.
The author also noted a previous meta-analysis showing that taking garlic extracts for over two months led to a 10% reduction in total and LDL cholesterol in patients with slightly elevated cholesterol levels.13
These results led the author to conclude:
“Garlic supplements are highly tolerated and may be considered as a complementary treatment option for hypertension, slightly elevated cholesterol, and stimulation of immunity.”13
Endothelial Function and Vascular Elasticity
Scientists conducted a double-blind, placebo-controlled, randomized clinical trial to test the effect of aged garlic extract on endothelial function and vascular elasticity—two important factors in the prevention of atherosclerosis.14
Sixty-five firefighters—subject to occupational stress—were randomized to receive either a placebo or aged garlic extract plus coenzyme Q10.
After one year of quarterly visits, the researchers documented a mean decrease in vascular stiffness in the aged garlic/CoQ10 group, as well as a significant improvement in the index of endothelial function.14
The study author concluded that aged garlic extract plays an important role in the prevention of atherosclerosis—even in challenging subjects such as those with chronic occupational stress.14
Collectively, these studies validate the ability of aged garlic extract to help protect against heart disease.
Summary
Garlic has been long recognized for its cardio-protective activity, but scientific validation of its heart benefits didn’t begin until the 1950s.
Aged garlic extract has well-documented mechanisms recognized to protect against heart disease risk factors.
If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.
References
- . Varshney R, Budoff MJ. Garlic and Heart Disease. J Nutr. 2016;146(2):416s-21s.
- . Ried K, Travica N, Sali A. The effect of aged garlic extract on blood pressure and other cardiovascular risk factors in uncontrolled hypertensives: the AGE at Heart trial. Integr Blood Press Control. 2016;9:9-21.
- Banerjee SK, Maulik SK. Effect of garlic on cardiovascular disorders: a review. Nutr J. 2002;1:4.
- Colin-Gonzalez AL, Santana RA, Silva-Islas CA, et al. The antioxidant mechanisms underlying the aged garlic extract- and S-allylcysteine-induced protection. Oxid Med Cell Longev. 2012;2012:907162.
- Available at: https://www.kyolic.ca/wp-content/uploads/2016/03/kyolic-aged-garlic-extract-info.pdf. Accessed July 20, 2018.
- Matsumoto S, Nakanishi R, Li D, et al. Aged Garlic Extract Reduces Low Attenuation Plaque in Coronary Arteries of Patients with Metabolic Syndrome in a Prospective Randomized Double-Blind Study. J Nutr. 2016;146(2):427s-32s.
- Morihara N, Hino A, Miki S, et al. Aged garlic extract suppresses inflammation in apolipoprotein E-knockout mice. Mol Nutr Food Res. 2017;61(10).
- Zeb I, Ahmadi N, Flores F, et al. Randomized trial evaluating the effect of aged garlic extract with supplements versus placebo on adipose tissue surrogates for coronary atherosclerosis progression. Coron Artery Dis. 2018;29(4):325-8.
- Xu C, Mathews AE, Rodrigues C, et al. Aged garlic extract supplementation modifies inflammation and immunity of adults with obesity: A randomized, double-blind, placebo-controlled clinical trial. Clin Nutr ESPEN. 2018;24:148-55.
- Takashima M, Kanamori Y, Kodera Y, et al. Aged garlic extract exerts endothelium-dependent vasorelaxant effect on rat aorta by increasing nitric oxide production. Phytomedicine. 2017;24:56-61.
- Borghi C, Cicero AF. Nutraceuticals with a clinically detectable blood pressure-lowering effect: a review of available randomized clinical trials and their meta-analyses. Br J Clin Pharmacol. 2017;83(1):163-71.
- Hermann M, Flammer A, Luscher TF. Nitric oxide in hypertension. J Clin Hypertens (Greenwich). 2006;8(12 Suppl 4):17-29.
- Ried K. Garlic Lowers Blood Pressure in Hypertensive Individuals, Regulates Serum Cholesterol, and Stimulates Immunity: An Updated Meta-analysis and Review. J Nutr. 2016;146(2):389s-96s.
- Larijani VN, Ahmadi N, Zeb I, et al. Beneficial effects of aged garlic extract and coenzyme Q10 on vascular elasticity and endothelial function: the FAITH randomized clinical trial. Nutrition. 2013;29(1):71-5.