Garlic Improves Arterial Elasticity and Markers of Cardiovascular Disease in Hypertensive Patients

by | Nov 10, 2020 | 2020, Botanicals, Cardiovascular Health, Garlic

Written by Angeline A. De Leon, Staff Writer. This study supports previous evidence for the benefits of aged garlic extract for long‑term preventative measure against cardiovascular disease.

garlicIn 2008, it was estimated that almost 50% of adults aged 25 years and older suffered from hypertension 1. Given that early stages of hypertension are largely asymptomatic, it is likely that this figure may actually be even higher 2, especially so today. Stage 1 hypertension, characterized by a systolic BP (SBP) of 140-159 mmHg and a diastolic BP (DBP) of 90-99 mmHg, represents one of the key risk factors associated with cardiovascular disease (CVD) 3. Though garlic is one of the oldest traditional medicines, it remains clinically relevant today in the form of aged garlic extract (AGE), an odorless garlic formulation containing valuable antioxidant compounds such as S-allylcysteine and S-1-propenylcysteine 4. A large body of research has established the powerful protective effects of AGE against CVD, indicating its efficacy in managing cholesterol levels 5 and hypertension 6 and improving blood circulation and oxidative stress levels 7. The BP-lowering effects of AGE have been partially attributed to its ability to induce vasorelaxation by increasing nitric oxide (NO) 8, and in animal studies, AGE has been linked to improvement of arterial pliability in hypertensive rats 9. Research in human subjects, however, has only found a non-significant tendency towards reduced arterial stiffness in hypertensive patients receiving AGE 10. Thus, in a 2020 study 11 published in Experimental and Therapeutic Medicine, scientists evaluated the impact of AGE on hypertensive patients, using newer technology (EndoPAT™) to assess arterial elasticity.

Using a randomized, double-blind, placebo-controlled study design, researchers enrolled a total of 57 overweight subjects (body mass index = 25-34.9 kg/m2) (mean age = 57.5 years) with high normal blood pressure and/or grade 1 hypertension. Subjects were randomly assigned to receive 2 ml of either aqueous AGE or identical placebo daily for approximately 3 months. At baseline, Week 6, and Week 12, anthropometric and blood pressure measurements were taken and fasting blood samples collected in order to determine lipid profile. In addition, EndoPAT™ testing was carried out at baseline and at Week 12 to calculate augmentation indices (AI, measure of arterial elasticity/stiffness).

Data showed a greater decrease in SBP (mean reduction of 8.9 mmHg vs. 3.8 mmHg, p = 0.056) and DBP (mean reduction of 5.6 mmHg vs. 2.6 mmHg, p = 0.038) for the AGE group, relative to placebo. Based on EndoPAT™ measures, patients receiving AGE also demonstrated significant reduction in AI over the course of the study (from a mean of 12.86 mmHg to 10.08 mmHg, p = 0.028), while subjects in the placebo group showed no such change in arterial elasticity (from 8.10 mmHg to 5.59 mmHg, p = 0.171). In addition, treatment with AGE was associated with a statistically significant decrease in triglyceride (TG) levels for AGE subjects vs. controls (p = 0.022).

Evidence from the present trial demonstrates the cardioprotective benefits of AGE consumption in overweight patients with hypertension. Intake of the specialized garlic extract was seen to improve key components of cardiovascular health, including SBP, DPB, and TG levels, as well as measures of arterial elasticity, based on new EndoPAT™ technology. Results suggest that AGE exerts a dynamic protective effect against the progression of CVD and warrants further study as a prophylactic measure against other forms of CVD. The primary limitation of the present study pertains to its relatively small sample size. Future studies replicating current findings with the additional measurement of oxidative stress biomarkers and NO levels would also be valuable.

Source: Gruenwald J, Bongartz U, Bothe G, et al. Effects of aged garlic extract on arterial elasticity in a placebo-controlled clinical trial using EndoPAT™ technology. Experimental and therapeutic medicine. 2020; 19: 1490-1499.

© Open Access article licensed under a Creative CommonsAttribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0 License.

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Posted November 9, 2020.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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