Association between the Mediterranean diet and myopia in US adolescents: a cross-sectional study of NHANES 2005–2008

Myopia is a critical public health issue, particularly among adolescents. This study investigates the association between adherence to a Mediterranean-style diet and the odds of myopia in US adolescents. A cross-sectional analysis was conducted using National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2008, involving 2473 participants aged 12-18 years. Adherence to the diet was assessed using the alternate Mediterranean diet (aMED) score. Myopia was defined as a spherical equivalent of ≤-0·50 dioptres (D). Multivariable logistic regression models adjusted for age, sex, race, education level, BMI, poverty income ratio and total energy intake were used to examine the association between aMED and myopia. Additionally, restricted cubic spline regression was used to explore non-linear relationships, and mediation analysis was conducted to identify potential biological pathways. Of the participants (median age: 15 years; 50·5 % male), 41 % were identified as having myopia. Participants with myopia had significantly lower aMED scores compared with non-myopic individuals (<i>P</i> < 0·05). Higher adherence to the aMED was associated with lower odds of myopia (OR: 0·830, 95 % CI 0·712, 0·968). A significant dose-response relationship was observed, with adolescents in the highest aMED quintile having a 41 % lower odds of myopia compared with the lowest quintile (OR: 0·592, 95 % CI 0·368, 0·952). The association was partially mediated by dietary cholesterol and eicosatetraenoic acid. In conclusion, adherence to a Mediterranean-style diet in adolescents is associated with a lower odds of myopia. Addressing diet quality may mitigate health risks related to myopia development.