Garlic Repels More Than Just Vampires

Garlic extract reduces cold and flu symptoms while improving immune cell functions

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(RxWiki News) Despite long traditional use, there is limited data about the influence of garlic on cold and flu treatment. Recent clinical trials are illuminating how this plant keeps us healthy.

New research reveals that aged garlic extract supports immune cell functioning, leading to less severe symptoms from cold and flu germs.

"Ask your pharmacist about garlic supplements to fight off the flu."

Garlic is well-known throughout the world for its medicinal value, but as of 2009 there had only been one clinical study on its effects on cold and flu symptoms.

This dearth of data led University of Florida research coordinator Meri P. Nantz to design a study that would shed some light on the specific actions of garlic on a cellular level.

Nantz, along with a team of researchers from the Food Science and Human Nutrition Department, recruited 120 students to take part in this study, which took place at the height of cold and flu season.

The students who were given aged garlic extract did not contract the cold/flu at a significantly different rate, but a notable difference was seen in the severity of the symptoms. There were 20 percent more symptoms reported in the placebo group. The placebo group also experienced 60 percent more days of decreased activity as a result of their illness; the placebo group also missed school or work 60 percent more than the garlic group.

Blood analysis showed that these symptom reductions were also accompanied by significant changes in the immune responses of the subjects. Students in the garlic group saw a dramatic increase in two types of important white blood cells: Natural Killer (NK) cells and gamma/delta T cells.

NK cells are the big guns for dealing with viruses, and gamma/delta T cells act as a kind of conductor for the orchestra that is your immune system.

The blood analysis also showed high levels of S-allyl-L-cysteine (SAC), a water-soluble compound found in garlic extracts. According to the authors, the high levels of SAC indicated that this compound is easy for the body to absorb.

The authors speculate that this chemical might have a direct relationship to the increase in white blood cells, and they also say that future research needs to be conducted to better understand this possible connection.

There were some limitations to this study, such as their reliance on patient self-reporting for the symptom analysis and the relatively small sample size.

The results of this double blind placebo controlled single center trial are published in the international journal Clinical Nutrition. The University of Florida Agricultural Experiment Station and Wakunaga of America, Inc. funded this study. Wakunaga also manufactured the aged garlic extract capsules used in the study. There were no reported conflicts of interest.

Last Updated:
October 8, 2012