Vitamins, Carotenoids Associated With Lower Risk for Cataract
However, strongest evidence comes from cohort studies, not randomized controlled trials
MONDAY, April 1, 2019 (Pharmacist's Briefing) -- Higher consumption of certain vitamins and carotenoids is associated with a significantly decreased risk for age-related cataract (ARC) in cohort studies, according to a meta-analysis published in the January issue of The American Journal of Clinical Nutrition.
Hong Jiang, from Xi'an Jiaotong University Health Science Center in China, and colleagues conducted a meta-analysis of randomized controlled trials (RCTs) and cohort studies published through June 2018 to assess dietary vitamin and carotenoid intake and ARC risk. The authors included eight RCTs and 12 cohort studies in the analysis.
The researchers found that most vitamins and carotenoids were significantly associated with a reduced risk for ARC in the cohort studies, including vitamin A (relative risk [RR], 0.81), vitamin C (RR, 0.8), vitamin E (RR, 0.9), β-carotene (RR, 0.9), and lutein or zeaxanthin (RR, 0.81). In RCTs, compared with placebo, vitamin E or β-carotene did not significantly reduce the risk for ARC. In cohort studies, the risk for ARC significantly decreased by 26 percent for every 10-mg/d increase in lutein or zeaxanthin intake, as well as by 18 percent for each 500-mg/d increase in vitamin C intake, by 8 percent for each 5-mg/d increase in β-carotene intake, and by 6 percent for every 5-mg/d increase in vitamin A intake.
"If we could delay the onset of ARC by 10 years, it could halve the number of people requiring surgery," a coauthor said in a statement.