Dietary flavonoid intake and lung cancer—A population‐based case‐control study

Abstract

BACKGROUND Laboratory studies suggest that flavonoids are antimutagenic and anticarcinogenic. To investigate the associations between commonly consumed flavonoid compounds and lung cancer, the authors conducted a population‐based case–control study of 558 lung cancer cases and a group of 837 controls. METHODS Dietary intakes of flavonoids were estimated by combining the intake frequency (collected by a food frequency questionnaire), portion size, and food composition data. Unconditional logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence limits (95% CLs) with an adjustment for potential confounders, including age, sex, race‐ethnicity, years of schooling, smoking status, pack‐years of tobacco smoking, and daily energy intake. RESULTS Lung cancer was associated inversely with the consumption of epicatechin (in 10 mg per day increment: OR, 0.64; 95% CL, 0.46–0.88), catechin (4 mg per day increment: OR, 0.49; 95% CL, 0.35–0.70), quercetin (9 mg per day increment: OR, 0.65; 95% CL, 0.44–0.95), and kaempferol (2 mg per day increment: OR, 0.68; 95% CL, 0.51–0.90) among tobacco smokers. There was little association between lung cancer and the flavonoid compounds mentioned above among nonsmokers. Regardless of smoking status, there was little association with total flavonoids: thearubigins, hesperetin, naringenin, and myricetin. In addition, consumption of vegetables, tea, and wine, all of which are rich sources of flavonoids, was associated inversely with lung cancer among tobacco smokers. CONCLUSIONS Certain flavonoid compounds, including epicatechin, catechin, quercetin, and kaempferol, were associated inversely with lung cancer among tobacco smokers, but not among nonsmokers. Further studies of these associations may be warranted. Cancer 2008. © 2008 American Cancer Society.

An In Vivo Antilymphatic Screen in Zebrafish Identifies Novel Inhibitors of Mammalian Lymphangiogenesis and Lymphatic-Mediated Metastasis

“…Regardless, these results suggest that antilymphatics may be best given in conjunction with other compounds that prevent tumor growth. Previous work has shown that kaempferol consumption has been associated with reduced risk of developing many cancers (38)(39)(40) and has also been shown to reduce VEGF expression in human cancer cell lines (41,42). To our knowledge, this study is the first to report VEGFR inhibition and antilymphatic activity for kaempferol.…”

Cancer Chemoprevention by Dietary Polyphenols

“…Not included in the meta-analyses was a case-control study in Los Angeles, CA with 558 cases and 837 controls. The results showed that high consumption of dietary epicatechin, mainly from black tea, was associated with significantly reduced risk of lung cancer, especially among smokers [95].…”

Green Tea and Its Extracts in Cancer Prevention and Treatment

“…Wang et al [73] pooled the results from six cohort studies with 1675 cases, among them prospective studies in Chinese workers exposed to lung carcinogens [74,75] and retrospective case control studies [76,77] and calculated a decreased risk in the high GT intake group. However, in 12 Chinese studies evaluated by Yuan [72,78], significance was only obtained for one group of tea drinkers in each study, which was not necessarily the group with the highest intake [71,74,79,80], or only in a trend analysis. A significantly increased lung cancer incidence was seen by Tewes et al [77] in Hong Kong Chinese, as was seen for some subgroups in other studies [71,72].…”