Dietary Factors May Help Prevent Cataract Development

Dietary factors for patients wishing to ward off cataracts should include eating more legumes, tomatoes, apples, and pears, according to research published in Eye. The study overturns prior thinking that emphasized more cruciferous and leafy greens.

The study included 72,160 participants (aged 40-69 years) who did not present with cataracts at baseline. All participants completed 1 to 5 24-hour questionnaires evaluating their dietary choices.. Follow-up took place for an average of 9.1 years. Statistical analysis adjusted for variables such as sociodemographic factors, lifestyle, and medical history.

Resulting cataracts at follow-up were either declared or noted by medical record codes. Of the sample, 5753 (8.0%) developed cataracts. The researchers stratified participants according to dietary factors and found that those who ate more fruits and vegetables had reduced cataract incidence (P <.0001). Individuals who consumed 6.5 servings or more per day exhibited an 18% decrease in risk (95% CI 24% to 11%), compared with those who ate fewer than 2 servings daily (HR, 0.82; 95% CI, 0.76 to 0.89; P <.0001).

Specifically, participants who ate more legumes had significantly reduced incidence (P =.0016), as well as those who ate 5.2 servings or more per week of tomatoes, compared with fewer than 1.8 servings (HR, 0.94; 95% CI 0.88 to 1.0). More than 7 servings per week of  apple and pear decreased risk, compared with fewer than 3.5 servings per week (HR, 0.89; 95% CI, 0.83 to 0.94; P <.0001). While these dietary factors were significantly associated with reduced incidence, citrus, berries, melons, cruciferous vegetables, and leafy greens all had nonsignificant benefits.

“Higher intake of legumes was significantly associated with a trend of lower cataract risk in our analysis. The Blue Mountains Eye Study showed a similar finding that the highest quintile of legume consumption group had significantly lower incidence of posterior subcapsular cataract compared with the lowest quintile, but no significant trend of this association was observed across quintiles, the researchers report. “These findings underscore the need to educate both doctors and patients to pay more attention to dietary factors, and recommend [fruit and vegetable] consumption for better cataract management.”

Previous studies have suggested vegetarianism may reduce cataract risk. A diet plentiful in vitamins A, C, D, E, and K1 are also reported to decrease risk, as well as green and yellow vegetables, rich in carotene and lutein. The Cataract in the Adult Eye Preferred Practice Pattern^® advises a balanced diet high in F&V, but no particular diet, the investigators noted.

The study also shows dietary factors can influence systemic issues. For instance, higher levels of fruit and vegetable intake is associated with higher high-density lipoprotein cholesterol (HDL-C), lower body mass index (BMI), HbA1c, and triglycerides, and fewer cases of hypertension and depression.

Limitations of this investigation include a population of primarily UK residents that may limit generalization, potential uncaptured cataract cases, an incomplete food set, possible changes in diet not found with the questionnaire, and no data for nondietary factors, such as hormone use or UV exposure.