APR 14, 2008
Cataract/Anterior Segment, Comprehensive Ophthalmology
Diets rich in lutein and zeaxanthin, the predominant carotenoids in the lens, are moderately associated with a decreased prevalence of nuclear cataract in older women, according to this ancillary study of the Women's Health Initiative (WHI). However, multivariate analysis found that other protective aspects of a healthy lifestyle associated with such diets may in part explain these relationships. Additionally, this is the first study to suggest dietary fat intake as a confounder attenuating the association of lutein- and zeaxanthin-rich diets with decreased cataract risk or as a risk factor for nuclear cataract development, a relationship the study's authors say deserves further exploration.
Subjects eligible for the study had enrolled in WHI at three of 40 sites and had baseline intakes of lutein plus zeaxanthin above the 78th or below the 28th percentiles measured from serum samples between 1994 and 1998. A total of 1802 women, who were between ages 50 and 79 upon WHI enrollment, participated in the current study. Between 2001 and 2004, they were measured for macular pigment optical density and underwent lens photography and eye examinations. Nuclear cataract was diagnosed in those given a nuclear sclerosis severity score of four or greater (on a scale from 0 to 7.1) in the worst eye or with a history of cataract extraction.
The association between lutein-and zeaxanthin-rich diets and decreased nuclear cataract risk was strengthened when the subjects were categorized by quintiles of lutein and zeaxanthin in their diet. Those in the highest quintile were 32% less likely to have received a nuclear cataract diagnosis compared with those in the lowest quintile, whereas, when considering the entire subject pool, there was a 23% difference between the high- and low-lutein plus zeaxanthin groups, which was barely statistically significant.
The results of this study add to the somewhat variable body of evidence from other studies and, like those before it, serve to once again encourage the consumption of a diet rich in fruits and vegetables to help ameliorate the aging process.
Dr. Arbisser has received honoraria and research grants from Alcon Laboratories Inc. and Advanced Medical Optics Inc.