Hindawi Publishing Corporation Journal of Biomedicine and Biotechnology Volume 2012, Article ID 503241, 28 pages doi:10.1155/2012/503241 Research Article The Safety of Cruciferous Plants in Humans: A Systematic Review Ori Scott, 1 Elaine Galicia-Connolly, 2 Denise Adams, 2 Soleil Surette, 2 Sunita Vohra, 2, 3 and Jerome Y. Yager 1 1 Pediatric Neurosciences, Department of Pediatrics, Stollery Children’s Hospital, University of Alberta, Room 3-469, Edmonton Clinic Health Academy (ECHA), 11405-87 Avenue, Edmonton, AB, Canada T6G 1C9 2 CARE Program, Department of Pediatrics, University of Alberta, Edmonton Clinic Health Academy (ECHA), 11405-87 Avenue, Edmonton, AB, Canada T6G 1C9 3 School of Public Health, University of Alberta, Edmonton Clinic Health Academy (ECHA), 11405-87 Avenue, Edmonton, AB, Canada T6G 1C9 Correspondence should be addressed to Jerome Y. Yager, jyager@ualberta.ca Received 27 July 2011; Accepted 11 October 2011 Academic Editor: Ikhlas A. Khan Copyright © 2012 Ori Scott et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Some cruciferous plants may serve as preventive treatments for several medical conditions; our objective was to systematically in- vestigate their safety in humans. Four electronic databases were searched, and, of 10,831 references identified, 50 were included. Data were extracted by two independent reviewers, whereafter the association between interventions and adverse events was asses- sed. Adverse events in 53 subjects were identified through clinical trials; of these, altered drug metabolism was rated as certainly/ likely caused by cruciferous plants. Adverse events in 1247 subjects were identified through observational studies, of which none received high causality ratings. Adverse events in 35 subjects were identified through case reports, of which allergies and warfarin resistance were rated as certainly/likely caused by cruciferous plants. We conclude that cruciferous plants are safe in humans, with the exception of allergies. Individuals treated with warfarin should consult their physician. Further investigation of uses of cruci- ferous plants in preventative medicine is warranted. 1. Introduction In the last decade, a rapid rise in the demand for natural health products has become evident. This prominent trend stems from increasing awareness of the potential for signifi- cant adverse effects caused by pharmacologic interventions, along with a growing interest in preventive medicine strate- gies [1]. A group of plants that has been shown to possess strong anti-inflammatory and antioxidative abilities is the crucif- erous plants of the Brassica genus. Brassica is a genus of plants in the Brassicaceae family. Vegetables of the family Brassicaceae (also called Cruciferae) are generally referred to as cruciferous vegetables. These vegetables are widely culti- vated, with many genera, species, and cultivars being raised for food production. The most common Brassica vegetables eaten by people are in a single species (B. oleracea), including kale, collard greens, cabbage, Brussels sprouts, kohlrabi, broccoli, and cauliflower. Numerous other species in the genus are also edible such as mustard (B. nigra), Chinese cab- bage (B. rapa), and oilseed rape (B. napus; sometimes re- ferred to as “rapeseed oil” or “canola”) [2]. Some members of this group have received wide acclaim as potential natural preventers or attenuators of several health conditions such as coronary artery disease, gastritis, and cancer [3–8]. Recent studies reveal that these therapeutic effects may extend to the fetus as well: an international case- control study showed that maternal consumption of cru- ciferous vegetables during pregnancy decreases the risk of childhood anaplastic astrocarcinomas [9]; a study in rats found that offspring of spontaneously hypertensive rats that consumed broccoli sprouts during gestation had lower blood pressure and reduced markers of oxidative stress and inflam- mation, compared to controls [10]. The impetus for this systematic review stems from work done in our laboratory that has shown the potential benefit of supplementing the diet of pregnant dams with broccoli sprouts in preventing perinatal brain injury. In this regard,