See corresponding editorial on page 17.
Garlic intake and cancer risk: an analysis using the Food and Drug
Administration’s evidence-based review system for the scientific
evaluation of health claims1,2
Ji Yeon Kim and Oran Kwon
Background: Numerous animal and in vitro studies provided evi-
dence for a relation between garlic intake and cancer risk reduction.
Several studies also reported an inverse association in humans.
However, no claims have been made about garlic intake and cancer
risk reduction with respect to food labeling.
Objective: The objective of this study was to evaluate the scientific
evidence for garlic intake with respect to the risk of different types
of cancer using the US Food and Drug Administration’s evidence-
based review system for the scientific evaluation of health claims.
Design: Literature searches were conducted by using the Medline
and EMBASE databases for the period 1955–2007 with search
terms Allium sativum, vegetables, diet, and nutrition in combination
with cancer, neoplasm, and individual cancers. The search was
limited to human studies published in English and Korean.
Results: With the use of the US Food and Drug Administration’s
evidence-based review system for the scientific evaluation of health
strength ofthe evidence thatsupports arelationbetween garlic intake
and reduced risk of different cancers with respect to food labeling.
Conclusions: There was no credible evidence to support a relation
between garlic intake and a reduced risk of gastric, breast, lung, or
endometrial cancer. Very limited evidence supported a relation be-
tween garlic consumption and reduced risk of colon, prostate,
esophageal, larynx, oral, ovary, or renal cell cancers.
Am J Clin
Food labels are widely used to convey the health benefits of
conventional foods or a component of food (eg, nutrient) to the
consumer. The increasing amount of health information available
regarding the health benefits of foods has resulted in consumer
interest in health issues and has become a leading factor in
purchasing decisions. Therefore, labeling and advertising should
not be misleading. The requirement to protect consumers and
ensure their right to obtain accurate information on food func-
tionality has led to the introduction of regulations about health
claims worldwide. In the United States, health claims were first
authorized by the US Food and Drug Administration (FDA) after
enactment of the Nutrition Labeling and Education Act of 1990
(1). Health claims are made on the label or in the labeling of
foods, including dietary supplements, that expressly or by im-
plication (including ‘‘third party’’ references, written statements,
symbols, or vignettes) characterize the relation between a sub-
stance and a disease or health-related condition (2). The Euro-
pean Union recently established a new regulation for health
claims (3). This new regulation requires that all health claims be
subjected to prior approval by the European Commission, which
operates through the standing committee of the European Food
Safety Authority. Although there is no worldwide consensus
regarding the scientific substantiation of health claims for food,
the scientific substantiation of health claims is under discussion
in the Codex Committee on Nutrition and Foods for Special
Dietary Uses (4). In Korea, the Health/Functional Food Act was
signed into law in 2002, and a new regulatory framework for
making health claims came into effect in 2004 (5). To protect
consumers from false or misleading claims, the FDA uses an
evidence-based review system to evaluate the relation between
food or a food component and disease (6).
Garlic is widely consumed as a spice in Korea. It is a vegetable
of the Allium genus and is characterized by a high content of
organosulfur compounds and flavonoids. A variety of compo-
nents, including nonsulfur compounds, work synergistically to
provide various health benefits (7). The major compounds that
are known to contribute to the pharmacologic effect are sulfur-
containing compounds, such as diallyl (8). However, variation in
processing yields quite different preparations because of the
complex chemistry of garlic. Although there are abundant sci-
entific articles that suggest that garlic intake may reduce cancer
risk, few systematic reviews or meta-analyses of human studies
have been performed on the consumption of garlic and its role in
limited types of cancer etiology (9, 10). Currently, there is no
claim about garlic intake and cancer risk reduction in food la-
beling. The aim of this study was to evaluate the scientific ev-
idence for garlic intake with respect to the risk of different types
of cancer using the FDA’s evidence-based review system for the
scientific evaluation of health claims (11).
1From the Division of Nutrition and Functional Food Standards, Korea
Food and Drug Administration, Seoul, Korea (JYK), and the Department of
Nutritional Science and Food Management, Ewha Women’s University,
Seoul, Korea (OK).
2Reprints not available. Address correspondence to O Kwon, Human
Ecology Building 301, Ewha Women’s University, 11-1 Daehyun-dong,
Seodaemun-gu, Seoul, 120-750, Korea. E-mail: email@example.com.
Received March 12, 2008. Accepted for publication August 31, 2008.
First published online December 3, 2008; doi: 10.3945/ajcn.2008.26142.
Am J Clin Nutr 2009;89:257–64. Printed in USA. ? 2009 American Society for Nutrition
by guest on June 7, 2013
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KIM AND KWON
by guest on June 7, 2013