Write a paragraph about study findings on relationship between veg diet and Alzheimer's. Talk about stuff like study design, important sample characteristics, sample size, effect sizes and confidence intervals, or any other info worth noting in this section. This study was embedded within the Rotterdam Study, a prospective population-based cohort study in the Netherlands, of which details have been described previously [22]. Briefly, the original study (RS-I) started in 1990 with 7,983 participants aged 55 years (birth years: 1897-1938), residing in the district Ommoord, a suburb of Rotterdam. The study was extended in 2000 (RS-II), with 3,011 participants who moved into the study area or reached the age of 55 years (birth years: 1906-1944). In 2006, the study was further enlarged (RS-III), with 3,932 participants aged 45 years (birth years: 1918-1960). Participants are invited for follow-up examination rounds every 3 to 6 years. Participants from all three sub-cohorts contributed to the current analysis. However, out of the 14,926 participants, 5,189 lacked data on dietary habits at study entry due to the implementation of dietary assessment after a pilot round (n = 271), prevalent dementia in combination with the lack of caregiver assistance to recall dietary habits (n = 393) or