Insufficient evidence for garlic in prevention or treatment of the common cold

January 01, 0001

Insufficient evidence for garlic in prevention or treatment of the common cold

Clinical Question:How effective is garlic for the prevention or treatment of the common cold?

Bottom line: There is no conclusive evidence to recommend garlic supplements as a preventative or treatment option for the common cold. A single, small trial suggested garlic might reduce the frequency of symptoms of the common cold if taken continuously as a daily prophylactic but the results require validation. On average individuals taking garlic had colds lasting 1.52 days while those taking a placebo had colds lasting 5.01 days. There is currently no evidence to help decide whether treating common colds with garlic will reduce symptom severity or days of illness. Anecdotally, adverse events reported include odour, and minor skin or respiratory irritation. The frequency of adverse effects could not be determined from the evidence available.

Caveat: Only one trial that met the selection criteria was identified, limiting the conclusions that can be drawn. Inclusion and exclusion criteria were not reported, nor were differences in comorbidity or concurrent illnesses. These factors reduce the generalisability of the trial and may have introduced bias into the results. No trial was identified that looked at whether taking garlic for symptoms of the cold reduces its severity or duration. However, in the included study, the number of days to recover from a cold was similar for both groups.

Context: Garlic is alleged to have antimicrobial and antiviral properties that relieve the common cold, among other beneficial effects. There is widespread usage of garlic supplements. The common cold is associated with significant morbidity and economic consequences. On average, children have 6 to 8 colds per year, and adults have 2 to 4.

Cochrane Systematic Review: Lissiman E et al. Garlic for the common cold. Cochrane Reviews 2009, Issue 3. Article No. CD006206. DOI: 10.1002/14651858. CD006206.pub2. This review contains one study involving 146 participants.

Cochrane PEARLS Practical Evidence About Real Life Situations. No. 206, November 2009.
Written by Brian R McAvoy. Published by the Cochrane Primary Care Group

Category: R. Respiratory. Keywords: garlic, common cold, upper respiratory infection
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 23 March 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care

To obtain Pearls directly, sign up here for the english language version

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.