The Association Between Dietary Factors And Age-related Cataract

ObjectiveTo explore the relationship of socio-demographic characteristics, dietary factors(total energy, carbohydrate, fat, protein, fruit, vegetables and sodium intake) withage-related cataract (ARC) in middle-aged and elderly men.MethodsA hospital-based case control study was conducted from April2010to August2011. A total of360cases aged45~85years old for cataract extraction and360frequency-matched controls in the same hospital for various acute, non-neoplastic,non-metabolic diseases were included in the study. All subjects were interviewedusing a structured interviewer-administrated questionnaire, coveringsocio-demographic characteristics, lifestyle habits, and detailed medical history.Simultaneously, a valid semi-quantitative food frequency questionnaire (FFQ)provided data on the dietary intakes of nutrients including carbohydrate, fat, protein,fruit and vegetables, sodium. Cases were medically diagnosed and classified fromslitlamp photographs using lens opacities classification system III. Analyses wereconducted using SPSS13.0. Multivariable adjusted odds ratios (ORs) and95%confidence intervals (CIs) were estimated for associations of three types of cataract(nuclear, cortical and posterior subcapsular cataract) or any cataract with dietaryfactors using conditional logistic regression models.Results1. In total,360cases and360frequency-matched controls aged45~85, were included in the study. The mean age of cases and controls was69.20±10.39and69.62±10.93. The most frequent type of cataract was cortical (n=190) followed bynuclear (n=107) and posterior subcapsular cataract (n=63).2. Conditional logistic regression analysis showed that total dietary intake ofcarbohydrate was positively associated with cortical cataract, compared to controlsin the lowest quartile, and the OR for cases in the highest quartile of intake was2.471(95%CI:1.348~6.043, P=0.027). Participants in the highest quartile ofpolyunsaturated fatty acids intake (PUFA) had2.7times the risk of nuclear cataractas did those in the lowest quartile (OR=2.742,95%CI:1.790~4.200, P=0.033).Higher dietary intakes of animal protein were protective for nuclear cataract (OR=0.841,95%CI:0.416~0.963, P=0.016) and posterior subcapsular cataract (OR=0.528,95%CI:0.148~0.869, P=0.023).3. After adjusting for multiple potential confounders, intake of fruit, vegetablesand total fruit and vegetables were inversely associated with ARC. Compared tocontrols in the lowest quartile, the risk of ARC for cases in the highest quartile ofintake decreased for19%(OR=0.814,95%CI:0.677~0.979, P=0.017),19%(OR=0.812,95%CI:0.691~0.945, P=0.004) and29%(OR=0.713,95%CI:0.608~0.937, P=0.001), respectively. The risk of ARC decreased with higher intakeof fruit (P=0.014), vegetables (P <0.001) and total fruit and vegetables (P=0.023).Intakes of fruit and vegetables were significantly inversely in relation to nuclearcataract (OR=0.690,95%CI:0.327~0.897, P=0.021) and cortical cataract (OR=0.721,95%CI:0.413~0.905, P <0.001).4. There was statistical significance between dietary sodium intake (14.18±3.80) g/d in cases and that in controls (13.02±3.28) g/d (t=3.726, P=0.001). Afteradjustment for multiple potential confounders, the dietary sodium intake waspositively associated with posterior subcapsular cataract. Subjects in the highestquartile of sodium intake had approximately twice the risk of posterior subcapsularcataract as did those in the lowest quartile (OR=2.017,95%CI:1.236~3.473, P<0.001). Conclusions1. A high intake of carbohydrate and PUFA may increase the odds of corticaland nuclear cataract, respectively, whereas high intake of protein, especially animalprotein, may protect against posterior subcapsular cataract.2. Increased consumption of fruit and vegetables may have a protective effecton ARC.3. Lower dietary sodium intake was likely to act protectively for thedevelopment of posterior subcapsular cataract.In conclusion, it is possible that dietary changes of target population, whichmeans to follow by the dietary guidelines for Chinese and a healthy well-balanceddiet may be beneficial to ARC.