Fermented Garlic Extract Improves Blood Pressure and Blood Flow in Adult Subject

by | Feb 1, 2023 | 2022, Blood Pressure, Botanicals, Cardiovascular Health, Garlic

Written by Taylor Woosley, Staff Writer. Results of the randomized controlled trial show that administration of one tablet of encapsulated FGE consisting of 180 mg of dried FGE containing 7 mg of inorganic NO2– significantly reduced systolic and diastolic blood pressure (p=0.001) compared to baseline values. 

garlicCardiovascular disease (CVD) continues to be the leading cause of mortality across both sexes and all races and ethnicities in the United States1. CVD includes coronary artery disease, heart disease, arrhythmias, and other types of vascular diseases2. Nitric oxide (NO) is a small free radical with critical signaling roles necessary to regulate the resistance of blood vessels and maintain adequate blood flow3. Low-grade inflammation and the uncoupling of endothelial nitric oxide synthase contributes significantly to oxidative stress and represents a hallmark of most cardiovascular diseases4.

The consumption of fermented black garlic (FBG) has been related to improvements in several cardiovascular disease factors including blood pressure, blood cholesterol levels, and atherosclerosis5. Garlic and its secondary metabolites have excellent health-promoting effects through its antioxidant, anti-inflammatory, and lipid-lowering properties6. Research has shown that FBG can reduce intracellular oxidant stress and stimulate nitric oxide generation in endothelial cells7.

Baik et al. conducted a randomized controlled study to assess whether fermented garlic extract (FGE) contributes to changes in blood flow (BF) in healthy adults, including regional cerebral blood flow (rCBF), carotid artery (CA) BF, peripheral blood flow (PBF), and blood pressure (BP). Subjects (n=58) were divided into one of two studies, a study of CA and BP and a study of rCBF and PBF. For the CA and BP study, participants were randomly divided into FGE (n=15) and placebo groups (n=15). Subjects had carotid Doppler ultrasounds performed to measure changes in the velocity of CA and had their blood pressure measured before ingesting the tablets to get a baseline value. FGE and placebo were administered single-dose 450 mg encapsulated FGE consisting of 180 mg of dried FGE containing 7 mg of inorganic NO2– and 450 mg placebo tablets, respectively.  After ingestion, CA velocity and BP measurements were performed again 30-60 min after.

In the rCBF and PBF group, subjects (n=28) were randomly divided into the FGE (n=15) and placebo groups (n=13). Before ingesting the tablet, subjects were examined using single photon emission computed tomography (SPECT) and digital infrared thermographic imaging (DITI) scanning. After consuming the tablet, SPECT and DITI measurements were again taken around 30-60 min after ingestion. No statistical analyses were performed between the two studies. Wilcoxon signed rank test was used to evaluate efficacy and before-after differences were measured using Mann-Whitney U tests. Quade’s test was used to control for baseline differences in age and covariates and to compare the outcome before and after ingestion.

Significant findings of the study are as follows:

  • In the CA and BP study, the FGE group had an average baseline systolic and diastolic BPs of 124.0 ±7 mm Hg and 79.4 ± 12.3 mm Hg, respectively. After ingestion of the FGE tablet, a marked reduction of systolic (16.93 mm Hg) and diastolic (12.34 mm Hg) BPs were observed 30 minutes after, which was significantly statistically different than the before values (p = 0.001).
  • In the FGE group, treatment with the FGE tablet caused a marked reductions in the peak systolic flow velocity (Psv) and peak diastolic flow velocity (Edv) in right the CCA (Z = −2.413, p = 0.016, Z = −3.114, p = 0.002), right ICA (Z = −2.480, p = 0.013), and left CCA (Z = −2.204, p = 0.028, Z = −2.240, p = 0.025).
  • In the rCBF and PBF study, regarding rCBF, statistically significant trends were found in the right and left frontal cortex and the right parietal cortex.
  • Additionally, statistically significant differences in body surface temperature (BST) between baseline and 30 min after ingestion of FGE tablets were noted in the following extremities: posterior forearm (F = 5.706, p = 0.025), palm (F = 4.864, p = 0.037), and plantar (F = 6.534, p = 0.017) areas.

Results of the study show that FGE consumption significantly decreased both systolic and diastolic BP 30 min after ingestion. Furthermore, FGE consumption resulted in statistically significant increases in the BST in extremities. Study limitations include the small number of participants, the lack of data on longer-term effects of FGE, and not performing NO metabolite serum measures.

Source: Baik, Ji Soo, Ji Hong Min, Sung Min Ju, Jae Hyun Ahn, Sung Hwa Ko, Hyun Soo Chon, Min Sun Kim, and Yong Il Shin. “Effects of Fermented Garlic Extract Containing Nitric Oxide Metabolites on Blood Flow in Healthy Participants: A Randomized Controlled Trial.” Nutrients 14, no. 24 (2022): 5238.

© 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 February 1, 2023.

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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