Aged Black Garlic Intake Lowers Diastolic Blood Pressure in Subjects with Hypercholesterolemia

by | May 18, 2022 | 2022, Blood Pressure, Cardiovascular Health, Garlic

Written by Taylor Woosley, Staff Writer. 6-week consumption of aged black garlic significantly reduced diastolic blood pressure compared to placebo (p=0.007), stratification by sex showed that more significant changes were noted in men and individuals with a DBP > 75 mm Hg (p<0.05). 

cardiovascular health - blood pressureCardiovascular disease (CVD) is prevalent around the world, with less than 1% of the population achieving ideal cardiovascular health 1. CVD is multifactorial and entails complex interactions between genetics and physiology that leads to increased oxidative stress, causing damage to DNA and proteins, which harm the structure and function of the cardiovascular system 2. Risk factors include elevated BMI, along with high blood pressure and glucose levels 3. Healthy lifestyle factors, such as following a nutritious diet, being active, and not smoking, can significantly help contribute to improved cardiovascular health 4.

Garlic may offer cardioprotective benefits and studies have shown the lipid-lowering, plasma anticoagulant, and antioxidant capabilities of this plant 5. Aged black garlic (ABG) is a form of garlic obtained from raw garlic (Allium sativum) using high temperature and humidity for an extended length of time 6. During the heating process, the defense molecules allicin are converted to compounds (S-allylcysteine (SAC), S-allylmercaptocysteine (SAMC), and S-1-propenylcysteine (S1PC)) which not only have higher stability, but also offer more robust antioxidant activity 7. Additionally, the aging process produces other macromolecules named melanoidins, offering anti-inflammatory properties and radical-scavenging activity 8.

Valls et al. conducted a randomized, crossover, double-blind, sustained and controlled study to assess the intake of ABG on subjects with hypercholesterolemia. Participants (n=67) were included in the study if they were age ≥ 18 years, had LDL cholesterol levels ≥ 115 mg/dL, with pre-existing hypercholesterolemia. Subjects were randomly assigned to one of two groups of sequences, half of the participants began the 6-week study by consuming 1 tablet per day containing ABG extract (550 mg, containing 250 mg of ABG extract) or placebo, with 3 weeks of washout. 33 subjects (mean age 53.7 ± 8.12 y; 18 females) were randomized in sequence 1 (ABG-Placebo) and 34 participants (52.7 ± 8.59 y; 17 females) were randomized in sequence 2 (Placebo-ABG). Participants completed a 3-day food record at baseline and after 6 weeks during both treatments to ensure the avoidance of lipid-lowering foods. At baseline, three weeks, and 6 weeks of intervention, blood pressure measurements were taken, along with lipid profiles and glucose levels. After the six-week intervention period, the results were as follows:

  • At 6 weeks, a significant decrease in DBP after consuming ABG was noted after placebo consumption (p=0.007). After ABG intake, DBP increased as well, reaching borderline significant compared to baseline (p=0.083).
  • After stratification by sex, a significant decrease in DBP after ABG consumption compared with placebo was observed in men and in individuals with a DBP > 75 mm Hg (p<0.05).
  • At 6 weeks, total cholesterol levels showed a quadratic decreasing trend after ABG treatment compared to baseline (p=0.047).
  • Regarding dietary adherence, at the end of the intervention periods, compared to baseline, a significant decrease in consumption of monounsaturated fatty acids was observed, without intertreatment differences (p<0.05).
  • Additionally, a significant decrease in polyunsaturated fatty acids was noted (p=0.029), as well as a significant increase in total fat (% of energy) (p=0.030) was observed after placebo treatment.

Study results show that use of daily ABG supplementation improved DBP in moderately hypercholesterolemic subjects, particularly in men and in individuals with a baseline DBP higher than 75 mm Hg. Future studies should further explore the use of ABG supplementation on various cardiometabolic biomarkers as a natural approach to treating cardiovascular conditions.

Source: Valls, Rosa M., Judit Companys, Lorena Calderón-Pérez, Patricia Salamanca, Laura Pla-Pagà, Berner Andrée Sandoval-Ramírez, Antonio Bueno et al. “Effects of an Optimized Aged Garlic Extract on Cardiovascular Disease Risk Factors in Moderate Hypercholesterolemic Subjects: A Randomized, Crossover, Double-Blind, Sustainedand Controlled Study.” Nutrients 14, no. 3 (2022): 405.

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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Posted May 18, 2022.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

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