Garlic's Effects on Inflammation and Immunity Evaluated by a Study

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By Agata P. | Updated: Aug 03, 2021

Garlic's Effects on Inflammation and Immunity Evaluated by a Study
General Information
  • 03 Jan 2018
  • USA
  • University of Florida
  • Percival, S. et al
  • Randomized clinical trial
  • 51 obese adults
  • 6 weeks

Numerous studies have found links between obesity and chronic low-grade inflammation.1 Such prolonged inflammatory states can increase one's risk of a wide range of health conditions, like cardiovascular disease.

In order to decrease the burden of obesity on people's health, research studies take interest in various herbs with potent anti-inflammatory and antioxidant properties, such as garlic.

The purpose of this particular scientific study was to evaluate the effects aged garlic extract has on chronic inflammation and immune function in obese adults.

The Study

It was a 2018 randomized clinical trial conducted by researchers from the University of Florida in Gainesville, Florida. Their findings were published in the Clinical Nutrition ESPEN journal.

There were 51 obese adults participating in the study. The average body mass index among them was 36.1 kg/m2. They were split into two groups with different treatments for six weeks:

  • The intervention group took capsules with 3.6 g of aged garlic extract per day.
  • The control group took placebo capsules.

Aged garlic extract was prepared by storing raw garlic in aqueous ethanol solution for up to 20 months.

Participants had their blood lipid and inflammatory markers as well as immune system responses (e.g. peripheral blood mononuclear cells) before and after the study.

The Results

After six weeks, the intervention group showed reduced levels of inflammation markers, such as interleukin-6 and tumor necrosis factor alpha. (Both of them are typically elevated in inflammation.)
There were also beneficial changes in immune cell distribution in women taking garlic (namely a higher proportion of gamma delta T cells and a lower proportion of natural killer T cells in lymphocytes).

Moreover, the garlic group had reduced concentrations of blood low-density lipoprotein (LDL) in comparison to the placebo group.

What Does this Mean?

The results of this study suggest garlic's role in managing low-grade inflammation in obese adults, thus preventing the development of chronic diseases associated with them.

Such findings offered adults struggling with obesity a natural and cost-effective way to prevent complications and prolong lifespan.

Other anti-inflammatory herbs include tomatoes, walnuts, strawberries, and spinach.


  • Clinical Nutrition ESPEN, Aged garlic extract supplementation modifies inflammation and immunity of adults with obesity: A randomized, double-blind, placebo-controlled clinical trial, 2018


  1. International Journal of Obesity. (2004). Obesity is the major determinant of elevated C-reactive protein in subjects with the metabolic syndrome. Retrieved February 23, 2021 from
  2. Diabetes Research and Clinical Practice. (2005). Relationship of obesity and visceral adiposity with serum concentrations of CRP, TNG- CRP, TNF-α and IL-6. Retrieved February 23, 2021 from