Groenten en soja tegen het ontstaan van kanker.*

Uit een studie blijkt dat verschillende groenten zoals broccoli, bloemkool,koolsoorten en soja chemische (bioactieve) stoffen bevatten die schade aan het DNA kunnen herstellen waardoor het ontstaan van kanker wordt voorkomen. In de groenten is de stof I3C (Indole-3-Carbinol) en in de soja het genisteïne hiervoor verantwoordelijk. Beide stoffen doen de aanmaak van de enzymen BRCA1 en BRCA2 en de glutathionsynthese bevorderen. Daardoor wordt DNA schade gerepareerd en het ontstaan van kanker tegengegaan. Door deze studie is het nu duidelijk geworden dat door de voeding die we eten het ontstaan van kanker kan worden voorkomen, volgens professor Eliot Rosen.

Eat Your Vegetables And Lessen Your Chances Of Developing Cancer

Need another reason to eat your vegetables? New research shows that some of them contain chemicals that appear to enhance DNA repair in cells, which could lead to protection against cancer development, say Georgetown University Medical Center researchers.
In a study published in the British Journal of Cancer (published by the research journal Nature) the researchers show that in laboratory tests, a compound called indole-3-carbinol (I3C), found in broccoli, cauliflower and cabbage, and a chemical called genistein, found in soy beans, can increase the levels of BRCA1 and BRCA2 proteins that repair damaged DNA.
Although the health benefits of eating your vegetables--especially cruciferous ones, such as broccoli--aren't particularly new, this study is one of the first to provide a molecular explanation as to how eating vegetables could cut a person's risk of developing cancer, an association that some population studies have found, says the study's senior author, Eliot M. Rosen, MD, PhD, professor of oncology, cell biology, and radiation medicine at Georgetown's Lombardi Comprehensive Cancer Center.
"It is now clear that the function of crucial cancer genes can be influenced by compounds in the things we eat," Rosen says. "Our findings suggest a clear molecular process that would explain the connection between diet and cancer prevention."
In this study, Rosen exposed breast and prostate cancer cells to increasing doses of 13C and genistein, and found that these chemicals boosted production of BRCA1, as well as its sister repair protein, BRCA2. Mutations in either of these genes can lead to development of breast, prostate and ovarian cancers.
Since decreased amounts of the BRCA proteins are seen in cancer cells, higher levels might prevent cancer from developing, Rosen says, adding that the ability of I3C and genistein to increase production of BRCA proteins could explain their protective effects.
Indole-3-carbinol can activate two pathways linked to cancer prevention: (1) aryl hydrocarbon receptor (AhR) signalling (which leads to expression of phase I enzymes (e.g., CYP1A1) via the xenobiotic response element) and (2) antioxidant/electrophilic response element signalling (resulting in expression of phase II detoxifying enzymes: e.g., oxido-reductases and glutathione-S-transferases). Thus, the ability of I3C to induce enzymes that metabolise genotoxic agents may contribute to cancer prevention.
The study was funded by the Susan G. Komen Breast Cancer Foundation and the National Cancer Institute and co-authors include Drs. Saijun Fan, MD, PhD, Qinghui Meng, MS, Karen Auborn, PhD, and Timothy Carter, PhD.
About Lombardi Comprehensive Cancer Center
The Lombardi Comprehensive Cancer Center, part of Georgetown University Medical Center and Georgetown University Hospital, seeks to improve the diagnosis, treatment, and prevention of cancer through innovative basic and clinical research, patient care, community education and outreach, and the training of cancer specialists of the future. Lombardi is one of only 39 comprehensive cancer centers in the nation, as designated by the National Cancer Institute, and the only one in the Washington, DC, area. For more information, go to http://lombardi.georgetown.edu.
Laura Cavender
lsc6@georgetown.edu
Georgetown University Medical Center
http://gumc.georgetown.edu (Februari 2006) (Opm. Meer over glutathion.)