L. Chasan-taber et al., A prospective study of carotenoid and vitamin A intakes and risk of cataract extraction in US women, AM J CLIN N, 70(4), 1999, pp. 509-516
Background: Oxidation of lens proteins plays a central role in the formatio
n of age-related cataracts, suggesting that dietary antioxidants may play a
role in prevention. However, the relation between specific antioxidants an
d risk of cataract remains uncertain.
Objective: Our objective was to examine prospectively the association betwe
en carotenoid and vitamin A intakes and cataract extraction in women.
Methods: A prospective cohere of registered female nurses aged 45-71 y and
free of diagnosed cancer was followed; in 1980, 50461 were included and oth
ers were added as they became 45 y of age for a total of 77466. Information
on nutrient intake was assessed by repeated administration of a food-frequ
ency questionnaire during 12 y of follow-up.
Results: During 761 762 person-years of follow-up, 1471 cataracts were extr
acted. After age, smoking, and other potential cataract risk factors were c
ontrolled for, those with the highest intake of lutein and zeaxanthin had a
22% decreased risk of cataract extraction compared with those in the lowes
t quintile (relative risk: 0.78; 950/0 CI: 0.63, 0.95; P for trend = 0.04).
Other carotenoids (alpha-carotene, X-carotene, lycopene, and beta-cryptoxa
nthin), vitamin A, and retinol were not associated with cataract in multiva
riate analysis. Increasing frequency of intakes of spinach and kale, foods
rich in lutein, was associated with a moderate decrease in risk of cataract
.
Conclusions: Lutein and zeaxanthin and foods rich in these carotenoids may
decrease the risk of cataracts severe enough to require extraction.