Abstract
It has been hypothesized that flavonoids in foods and beverages may reduce cancer risk through antioxidation, inhibition of inflammation, and other antimutagenic and antiproliferative properties. We examined associations between intake of 5 flavonoid subclasses (anthocyanidins, flavan-3-ols, flavones, flavonols, and flavanones) and lung cancer risk in a population-based case-control study in Montreal, Canada (1061 cases and 1425 controls). Flavonoid intake was estimated from a food frequency questionnaire that assessed diet 2 yr prior to diagnosis (cases) or interview (controls). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. Overall, total flavonoid intake was not associated with lung cancer risk, the effect being similar regardless of sex and smoking level. However, low flavonoid intake from food, but not from beverages, was associated with an increased risk. The adjusted ORs (95% CIs) comparing the highest vs. the lowest quartiles of intake were 0.63 (0.47–0.85) for total flavonoids, 0.82 (0.61–1.11) for anthocyanidins, 0.67 (0.50–0.90) for flavan-3-ols, 0.68 (0.50–0.93) for flavones, 0.62 (0.45–0.84) for flavonols, and 0.70 (0.53–0.94) for flavanones. An inverse association with total flavone and flavanone intake was observed for squamous cell carcinoma but not adenocarcinoma. In conclusion, low flavonoid intake from food may increase lung cancer risk.
ACKNOWLEDGMENT
This work was done at the University of Montreal Hospital Research Centre (CRCHUM), Montreal, Canada.
This research was funded by the Canadian Cancer Society (grant #19912), and the Guzzo Chair of the Cancer Research Society and Great West Life. Dr. Parent is supported by a Career Investigator Award from the Fonds de la recherche en santé du Québec (FRSQ). Dr. Abrahamowicz is a James McGill Professor. Dr. Siemiatycki holds a Canada Research Chair in Environmental Epidemiology and Population Health and the Guzzo Chair in Environment and Cancer. Dr. Koushik was supported by a Chercheur-Boursier Award of the FRSQ and currently holds a New Investigator Award of the Canadian Institutes of Health Research.
Krista Yorita Christensen and Adonia Naidu contributed equally to this work.