Heavy Metal Exposure From Multigrain Rice Intake And Cataract Risk In South Korean Adults

Heavy metal exposure is known to contribute to eye diseases, and multigrain rice, which is commonly consumed in South Korea, may retain higher levels of these contaminants. This study aimed to investigate whether frequent multigrain rice intake is associated with increased exposure to cadmium, lead, mercury, and arsenic, as well as a higher risk of cataract.

A nationwide, cross-sectional survey of South Korean adults.

Data from 8,622 adults aged 20 years and older who participated in the 2008–2009 Korea National Health and Nutrition Examination Survey were analyzed. Cataract presence and subtypes were diagnosed by ophthalmologists. Multigrain rice intake was assessed and categorized into quartiles. Associations between multigrain rice intake, blood heavy metal concentrations, and cataract outcomes were evaluated using survey-weighted mean comparisons and survey-weighted multivariate and multinomial logistic regression models.

Participants in the highest quartile of multigrain rice intake showed higher blood concentrations of cadmium and arsenic compared with those in the lowest quartile. They also exhibited a 30% higher likelihood of having cataracts (adjusted odds ratio = 1.30, p < 0.05) and a 1.33-fold higher risk of nuclear cataract (relative risk ratio = 1.33, p < 0.05).

Frequent consumption of multigrain rice may elevate cataract risk among South Korean adults, potentially due to increased exposure to cadmium and arsenic. These findings suggest that heavy metal contamination in multigrain rice should be considered when developing dietary guidelines and cataract prevention strategies.