Christen WG, et al. Dietary carotenoids, vitamins C and E, and risk of cataract in women: a prospective study. Arch Ophthalmol. Jan 2008;126(1):102-109.
To determine the effects of dietary carotenoids on cataract formation in women, this prospective observational study was undertaken with 35,551 female participants for 10 years. Cataract formation and visual acuity were the primary outcome measures. Reduced risk of cataract formation (18%) was associated with increased dietary lutein/zeaxanthin intake. Randomized, clinical trials of lutein/zeaxanthin in both men and women are necessary to determine if lutein supplementation may also reduce cataract risk.
Ros MM, Bueno-de-Mesquita HB, Kampman E, et al. Plasma carotenoids and vitamin C concentrations and risk of urothelial cell carcinoma in the European Prospective Investigation into Cancer and Nutrition. Am J Clin Nutr. 2012 Oct;96(4):902-10.
This study invovled 856 patients with newly diagnosed urothelial cell carcinoma (UCC) who were were matched with 856 cohort members by sex, age at baseline, study center, date and time of blood collection, and fasting status. Plasma carotenoids including alpha and beta carotenes, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin were measured by using reverse-phase HPLC. The plasma vitamin C was measured by a colorimetric assay. Incidence rate ratios (IRRs) were estimated by using conditional logistic regression with adjustment for smoking status, duration, and intensity. Researchers report that the risk of UCC decreased with greater concentrations of plasma carotenoids (IRR for the highest compared with the lowest quartile: 0.64; 95% CI: 0.44, 0.93; P-trend = 0.04). Plasma lutein was inversely associated with risk of nonaggressive UCC (IRR: 0.56; 95% CI: 0.32, 0.98; P-trend = 0.05). Plasma beta-carotene was also inversely associated with aggressive UCC (IRR: 0.51; 95% CI: 0.30, 0.88; P-trend = 0.02), but no association was observed between plasma vitamin C and risk of UCC.
Plasma lutein and beta-carotene may reduce the risk of UCC.