January 2013

Aged Garlic for the Cold and Flu

A recent study reports that aged garlic supplementation may reduce the severity of cold and flu symptoms.

Garlic is a culinary herb that is widely used for the treatment and prevention of cardiovascular disease and cancer. Numerous controlled trials have examined the effects of oral garlic on serum lipids. Multiple cases of bleeding have been associated with garlic use, and caution is warranted in patients at risk of bleeding or prior to some surgical or dental procedures

The new study recruited 120 healthy individuals, who were randomly assigned to take 2.56 grams daily of either aged garlic extract or a placebo pill. Neither the researchers nor the individuals were aware of the group assignments.

Individuals consuming garlic for 45 days showed a significant increase in the production of immune cells, compared to the placebo individuals. Ninety days into the study, the proportion of individuals acquiring the cold or flu was not significantly different between groups. However, the garlic group had a significant reduction in illness symptom severity, illness duration, and missed days of school or work.

More research on this topic is warranted.

For more information about integrative therapies for the common cold and flu, please visit Natural Standard's Comparative Effectiveness database.


  1. Nantz MP, Rowe CA, Muller CE et al. Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition intervention. Clin Nutr. 2012 Jun;31(3):337-44. 
  2. Natural Standard: The Authority on Integrative Medicine. 

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