section name header

Evidence summaries

Garlic: Protective Effects Against Cancer

High dietary garlic consumption might possibly be associated with decreased risks of laryngeal, gastric, colorectal, and endometrial cancers and adenomatous colorectal polyps but evidence from controlled studies is lacking. Level of evidence: "D"

A technology assessment report 1 on the protective effects of garlic against cancer was abstracted in the Health Technology Assessment Database 2. Using any garlic supplement for less than 3 to 5 years was not associated with decreased risks of breast, lung, gastric, colon, or rectal cancer. Some case-control studies suggest that high dietary garlic consumption may be associated with decreased risks of laryngeal, gastric, colorectal, and endometrial cancers, and adenomatous colorectal polyps.

Multipleadverse effects, including breath and body odour, dermatitis, bleeding, abdominal symptoms, and flatulence have been reported but the causality of the adverse effects was not clear, except for breath and body odour. Whether adverse effects occur more commonly with certain preparations than others was not established.

References

  • Mulrow C, Lawrence V, Ackermann R, Gilbert Ramirez G, Morbidoni L, Aguilar C, Arterburn J, Block E, Chiquette E, Gardener C, Harris M, Heidenreich P, Mullins D, Richardson M, Russell N, Vickers A, Young V. Garlic: effects on cardiovascular risks and disease, protective effects against cancer, and clinical adverse effects. Evid Rep Technol Assess (Summ) 2000 Oct;(20):1-4. [PubMed]
  • Health Technology Assessment Database: HTA-20010948. The Cochrane Library, Issue 1, 2004. Chichester, UK: John Wiley & Sons, Ltd.

Primary/Secondary Keywords