Red Blood Cell DHA Is Inversely Associated with Risk of Incident Alzheimer's Disease and All-Cause Dementia: Framingham Offspring Study

• Published in: Nutrients 2022-06, Vol.14 (12), p.2408
• Main Authors: Sala-Vila, Aleix, Satizabal, Claudia L, Tintle, Nathan, Melo van Lent, Debora, Vasan, Ramachandran S, Beiser, Alexa S, Seshadri, Sudha, Harris, William S
• Format: Article
• Language: English
• Subjects: Aged; Alzheimer Disease - epidemiology; Alzheimer Disease - prevention & control; Alzheimer's disease; Apolipoprotein E; Apolipoprotein E4 - genetics; Apolipoproteins E; Biomarkers; Blood; brain health; Cardiovascular disease; Cognitive ability; Cohort Studies; Confidence intervals; Dementia; Dementia disorders; Diabetes; Dietary intake; Docosahexaenoic acid; Docosahexaenoic Acids; elders; Erythrocytes; Fatty acids; Health aspects; Humans; lipids; neurodegeneration; Neuropsychology; Offspring; omega-3; Omega-3 fatty acids; Plasma; Risk; Risk factors; Statistical analysis; Statistics
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu14122408

Docosahexaenoic acid (DHA) might help prevent Alzheimer's disease (AD). Red blood cell (RBC) status of DHA is an objective measure of long-term dietary DHA intake. In this prospective observational study conducted within the Framingham Offspring Cohort (1490 dementia-free participants aged ≥65 years old), we examined the association of RBC DHA with incident AD, testing for an interaction with carriership. During the follow-up (median, 7.2 years), 131 cases of AD were documented. In fully adjusted models, risk for incident AD in the highest RBC DHA quintile (Q5) was 49% lower compared with the lowest quintile (Q1) (Hazard ratio [HR]: 0.51, 95% confidence interval [CI]: 0.27, 0.96). An increase in RBC DHA from Q1 to Q5 was predicted to provide an estimated 4.7 additional years of life free of AD. We observed an interaction DHA × carriership for AD. Borderline statistical significance for a lower risk of AD was observed per standard deviation increase in RBC DHA (HR: 0.71, 95% CI: 0.51, 1.00, = 0.053) in carriers, but not in non-carriers (HR: 0.85, 95% CI: 0.65, 1.11, = 0.240). These findings add to the increasing body of literature suggesting a robust association worth exploring dietary DHA as one strategy to prevent or delay AD.