Garlic and Cancer: A Critical Review of the Epidemiologic Literature
Open Access
- 1 March 2001
- journal article
- review article
- Published by Elsevier in Journal of Nutrition
- Vol. 131 (3), 1032S-1040S
- https://doi.org/10.1093/jn/131.3.1032s
Abstract
Animal and in vitro studies provide evidence of an anticarcinogenic effect of active ingredients in garlic. This review of the epidemiologic literature on garlic consumption addresses cancers of the stomach, colon, head and neck, lung, breast and prostate. Nineteen studies reported relative risk estimates for garlic consumption and cancer incidence. Site-specific case-control studies of stomach and colorectal cancer, in which multiple reports were available, suggest a protective effect of high intake of raw and/or cooked garlic. Cohort studies confirm this inverse association for colorectal cancer. Few cohort and case-control studies for other sites of cancer exist. Garlic supplements, as analyzed in four cohort studies and one case-control report, from two distinct populations, do not appear to be related to risk. Low study power, lack of variability in garlic consumption categorization within studies and poor adjustment for potential cofounders may limit the reliability of any conclusions regarding garlic supplements. However, an indication of publication bias was also found by visual inspection of a funnel plot and in a log-rank test (P = 0.004). Evidence from available studies nevertheless suggests a preventive effect of garlic consumption in stomach and colorectal cancers. The study limitations indicate the need for more definitive research and improved nutritional epidemiologic analyses of dietary data.Keywords
This publication has 29 references indexed in Scilit:
- DIET, NUTRIENTS, AND GASTROINTESTINAL CANCERGastroenterology Clinics of North America, 1998
- A prospective cohort study on the relationship between onion and leek consumption, garlic supplement use and the risk of colorectal carcinoma in The NetherlandsCarcinogenesis: Integrative Cancer Research, 1996
- Consumption of onions and a reduced risk of stomach carcinomaGastroenterology, 1996
- Allium vegetable consumption, garlic supplement intake, and female breast carcinoma incidenceBreast Cancer Research and Treatment, 1995
- Risk factors for esophageal cancer in Shanghai, China. II. Role of diet and nutrientsInternational Journal of Cancer, 1994
- Diet and risk of gastric cancer. A population‐based case‐control study in SwedenInternational Journal of Cancer, 1993
- Garlic and its significance for the prevention of cancer in humans: a critical viewBritish Journal of Cancer, 1993
- A case‐control study of gastric cancer and diet in ItalyInternational Journal of Cancer, 1989
- Publication Bias and Dissemination of Clinical ResearchJNCI Journal of the National Cancer Institute, 1989
- Distribution of quercetin and kaempferol in lettuce, kale, chive, garlic chive, leek, horseradish, red radish, and red cabbage tissuesJournal of Agricultural and Food Chemistry, 1985