Researchers observed that among the 88 participants who completed the study, those who ingested the garlic extract supplement had modified endothelial biomarkers—indicators associated with cardiovascular risk—by the end of the intervention period.
“This suggests that [garlic extract] can be used to suppress chronic inflammation in obese individuals,” wrote the authors, affiliated with the University of Medical Sciences in Poznan, Poland, and Rutgers University.
Their report was published online ahead of print in Biomedicine & Pharmacotherapy, due for printing in the upcoming June edition of the journal.
The main outcome the researchers analyzed was the potential effects of garlic on arterial stiffness and endothelial function among participants with a body mass index (BMI) greater than 25.
“The first line of defense against obesity and its comorbidities is lifestyle modification,” they argued. “One of the most recognizable functional foodstuffs [for this] is garlic, one of a few plants that contain allyl-substituted sulfur compounds, which has served as a remedy for various ailments since the antiquity.”
Study design: Participant recruitment and supplement intervention
Individuals were eligible to participate if they were aged 25-60 years and met the BMI criteria set by the researchers. Another consideration was stability of body weight, no drug-treated hypertension, and no history of coronary artery disease, stroke, and congestive heart failure.
For the randomized, double-blind study, researchers divided participants into two groups, assigned to receive garlic or placebo. Participants were asked to continue their habitual exercise and diet regimes unchanged for the duration of the study.
Polish pharmaceutical company Olimp Laboratories provided the capsules. Participants were instructed to consume two capsules with their breakfast each day for three months.
The Garlicin supplement group received odorless extract of garlic with 2% allicin dosed at 400 mg per day. The placebo group’s capsule contained pure microcrystalline cellulose.
Participants visited a clinic for researchers to make measurements on body size and weight, blood pressure, and arterial stiffness. Researchers also conducted biochemical analysis of metabolic parameters such as plasma total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides.
The researchers observed “three months garlic supplementation decreases arterial stiffness index,” they wrote. This builds on previous studies on garlic extract's benefits, the researchers argued, citing results from studies like one published in 2005 on men with coronary artery disease, and another from 2013 on patients with ischemic stroke.
One major limitation of the study is the relatively small number of included individuals. “The main reason for this was the very rigorous inclusion and exclusion criteria,” they wrote.
“However, these criteria enabled us to select a homogenous group of subjects not encumbered by diseases or states that might significantly affect the results of the study.”
“The role of garlic in cardiovascular prevention needs further investigation, but it appears that supplementation with garlic could be a useful therapy for obese patients,” they added.
Source: Biomedicine & Pharmacotherapy
Published online ahead of print, https://doi.org/10.1016/j.biopha.2018.03.131
Garlic extract favorably modifies markers of endothelial function in obese patients –randomized double blind placebo-controlled nutritional intervention
Authors: Monika Szulińska, et al.