Associations of dietary patterns and CSF biomarkers for Alzheimer’s disease in a population-based sample of 70-year-olds

Background: Diet could be a modifiable factor in the prevention of Alzheimer’s disease (AD). Western-style dietary patterns are considered to increase the risk, while Mediterranean-style dietary patterns are considered protective. The aim of this study was to investigate the relation between dietary patterns and CSF biomarkers of relevance for AD. Method: Data was derived from the population based Gothenburg H70 Birth Cohort Studies in Gothenburg, Sweden (n=1203). CSF levels of β-amyloid (Aβ)42, total tau, and phosphorylated tau were measured with ELISA. Dietary intake was determined by the diet history method (n=861). Principal component analysis were performed to reduce 21 food groups into factors representing dietary patterns. Logistic regression analyses, with CSF biomarkers as dependent variables (pathological/not pathological), and linear regression analyses with CSF biomarkers as continuous variables, were performed on the dementia-free participants with both CSF and dietary data (n=269, 49% women). Analyses were adjusted for APOE ε4 status, energy intake, education, BMI, physical activity and sex. Analyses were also performed stratified by sex. Result: Four factors representing dietary patterns were derived from the principal component analysis. A western-style dietary pattern, a Mediterranean-style dietary pattern, a mixed dietary pattern with alcoholic beverages and a dietary pattern of high fat dairy products, eggs and refined cereal products. The odds ratio of having pathological values of total tau was higher among those with a higher compliance to a western-style dietary pattern (OR 1.37; 95%CI 1.02-1.80). The linear regression model indicate the same trend (r2=0.06, B=0.04, p=0.08). When stratified by sex, the odds ratio of having pathological values of phosphorylated tau was higher for those with a higher intake of high fat dairy products, eggs and refined cereal products among men (OR 3.38; 95%CI 1.22-9.36). We could not find an association between the other dietary patterns and CSF biomarkers. Conclusion: Our results indicate an association between western-style dietary patterns and increased levels of total tau and phosphorylated tau. However, there was no relation between a healthier Mediterranean-style dietary pattern and CSF biomarkers for AD.