Serum carotenoid levels are positively associated with DNA methylation of thioredoxin-interacting protein.

Carotenoids have been reported to exert protective effects against age-related diseases via changes in DNA methylation. Although lower DNA methylation is associated with age-related diseases, only a few studies have investigated the factors influencing DNA methylation. Carotenoids may be a factor linking TXNIP to specific pathophysiological functions. The aim of this study was to examine whether serum carotenoid levels are associated with DNA methylation levels. We conducted a cross-sectional study using 376 health examination participants (169 men). DNA methylation levels were determined using a pyrosequencing assay. Serum carotenoid levels were determined by high-performance liquid chromatography. Multivariable regression analyses were performed to examine the associations between DNA methylation levels and serum carotenoid levels with adjustment for age, BMI, HbA1c, CRP, smoking habits, alcohol consumption, exercise habits, and percentage of neutrophils. Multiple linear regression analyses showed that DNA methylation levels were positively associated with serum levels of zeaxanthin/lutein ( [95%CI]: 1.935 [0.184, 3.685]), β-cryptoxanthin (1.447 [0.324, 2.570]), α-carotene (1.061 [0.044, 2.077]), β-carotene (1.272 [0.319, 2.226]), total carotenes (1.255 [0.040, 2.469]), total xanthophylls (2.133 [0.315, 3.951]), provitamin A (1.460 [0.402, 2.519]), and total carotenoids (1.972 [0.261, 3.683]) in men (all <0.05). Of these, provitamin A showed the stronger association (standardized =0.216). No significant association of DNA methylation and serum carotenoid was observed in women. The findings of this study suggest that carotenoid intake may protect against age-related diseases by altering DNA methylation status in men.