To examine the relationship between adherence to a modified Mediterranean diet—distinguishing between non-fermented milk and fermented milk products—and overall mortality in two population-based Swedish cohorts representing central and northern Sweden. We hypothesize that higher adherence to a modified Mediterranean diet that includes fermented milk products will be linked to lower total mortality, while non-fermented milk may weaken the beneficial relationship between Mediterranean diet adherence and longevity. We also expect these associations to be consistent across both the SIMPLER and NSHDS cohorts, though regional differences in milk consumption could influence the effect sizes. In this project we will use questionnaire data from SIMPLER (1997, 2008/2009 and 2019) and mortality data/date and cause of death) from the the Swedish death register.