Association of dietary vitamin K-1 intake with the incidence of cataract surgery in an adult mediterranean population a secondary analysis of a randomized clinical trial
Camacho-Barcia, M. L.; Bullo, M. ; Garcia-Gavilan, J. F. ; Ruiz-Canela, Miguel
; Corella, D. ; Estruch, R. ; Fito, M. ; García Layana, Alfredo
; Aros, F. ; Fiol, M. ; Lapetra, J.; Serra-Majem, L.; Pinto, X.; Garcia-Arellano, A.; Vinyoles, E. ; Sorli, J. V.; Salas-Salvado, J.
IMPORTANCE Cataract, one of the most frequent causes of blindness in developed countries, is strongly associated with aging. The exact mechanisms underlying cataract formation are still unclear, but growing evidence suggests a potential role of inflammatory and oxidative processes. Therefore, antioxidant and anti-inflammatory factors of the diet, such as vitamin K-1, could play a protective role. OBJECTIVE To examine the association between dietary vitamin K-1 intake and the risk of incident cataracts in an elderly Mediterranean population. DESIGN, SETTING, AND PARTICIPANTS A prospective analysis was conducted in 5860 participants from the Prevencion con Dieta Mediterranea Study, a randomized clinical trial executed between 2003 and 2011. Participants were community-dwelling men (44.2%) and women (55.8%), and the mean (SD) age was 66.3 (6.1) years. MAIN OUTCOMES AND MEASURES Dietary vitamin K-1 intake was evaluated using a validated food frequency questionnaire. The time to the cataract event was calculated as the time between recruitment and the date of the occurrence to cataract surgery, the time to the last visit of the follow-up, date of death, or the end of the study. Hazard ratios and 95% CIs for cataract incidence were estimated with a multivariable Cox proportional hazards model. RESULTS Participants were community-dwelling men (44.2%; n = 868) and women (55.8%; n = 1086), and the mean (SD) age was 66.3 (6.1) years. After a median of 5.6 years follow-up, we documented a total of 768 new cataracts. Participants in the highest tertile of dietary vitamin K1 intake had a lower risk of cataracts than those in the lowest tertile (hazard ratio, 0.71; 95% CI, 0.58-0.88; P =.002), after adjusting for potential confounders. CONCLUSIONS AND RELEVANCE High intake of dietary vitamin K-1 was associated with a reduced risk of cataracts in an elderly Mediterranean population even after adjusting by other potential confounders.