Dairy and fish consumption and the risk of mild cognitive impairment and dementia

Background There are inconsistent evidence for the association between fish consumption and dementia risk, and emerging evidence suggesting that dairy consumption is associated with lower dementia risk, based on a limited number of prospective cohort studies. Methods We investigated the association of dairy and fish consumption with the risk of developing mild cognitive impairment (MCI) and dementia. High intake of daily consumption of milk and dairy products and consumption of fish at least three servings per week were determined at baseline for 1,164 community-living and cognitively normal Chinese individuals aged 55 + in the Singapore Longitudinal Ageing Study (SLAS-1), who were followed-up (average 3.5 years) for incident cases of MCI and dementia determined by established criteria. Results The participants’ mean (SD) age was 65.1 (6.9) years, 66.8% were female. Controlling for sex, age, low or no education, APOE-e4 status, physical, social and productive activity, depression (GDS ≥ 5), central obesity, prediabetes/diabetes, hypertension, abnormal lipids, cardiac diseases, and daily fruit/vegetable intake in multivariable analysis, daily intake of milk and dairy products was significantly associated with lower risk of incident MCI (OR = 0.61; 95% CI = 0.39–0.96) or MCI-dementia (OR = 0.62; 95% CI = 0.40–0.95). Fish intake was not significantly associated with lowered risk of incident MCI and MCI-dementia, (OR = 0.74, 95%CI = 0.49–1.13 for MCI; OR = 0.76, 95% CI = 0.51–1.14 for MCI-dementia). Conclusions High dairy intake was associated with approximately 40% reduced risk of MCI or dementia. There is weak support in this study of an association between fish intake and MCI-dementia risk. Trial Registration: ClinicalTrials.gov NCT03405675. Registered 23 January 2018 (retrospectively registered).