The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 6 No.
2 • April–May 2003
Protection by Quercetin Against Cooking Oil Fume-Induced Lung Cancer in Taiwanese Women
Lung cancer is the leading cause of cancer death for Taiwanese women, even though fewer than 10% of Taiwanese women smoke. A recent study of nonsmoking women who lived with a smoking husband indicated a 30% higher risk for lung cancer than those with a nonsmoking husband, but the relationship was not significant. However, the researchers found that there was a significant relationship for women who prepared meals in a kitchen without a fume vacuum and who heated oil to a high temperature. A recent paper reports that benzo[a]pyrene-7,8-diol-9,10-epoxide N-2 deoxyguanosine (BPDE-N-2-dG) adduct was identified as the major bulky DNA adduct after treatment of human lung adenocarcinoma CL-3 cells with cooking oil fumes (COF) from frying fish and that this adduct has been linked with the p53 (a tumor-suppressor gene) hot-spot mutation in human lung tumors. Thus, the authors propose that BPDE-N-2-dG in cooking oil fumes may play an important role in lung cancer development of nonsmoking Taiwanese women.
The researchers cite a recent epidemiological study that shows a significant inverse relation between lung cancer risk and the flavonoid quercetin found in foods such as onions and apples. Quercetin may reduce DNA damage caused by hydrogen peroxide and benzo[a]pyrene and NFkappaB binding activity. Quercetin was found to effectively suppress COX2 (cyclooxygenase-2) the activation of which has been associated with the development of many cancers) in colon cancer cells. The results of their study demonstrated that quercetin inhibited not only cooking oil fume-induced COX2 expression but also cooking oil fume-induced CYP1A1 (cytochrome P450 1A1) transcription.
Quercetin, like most antioxidants, can become a pro-oxidant and mutagen in excessive quantities.
- Lin et al. Protection by quercetin against cooking oil fumes-induced DNA damage in human lung adenocarcinoma CL-3 cells: role of COX2. Nutr Cancer 44(1):95-101 (2002).