Omega-3 fatty acids, hypertension and risk of cognitive decline among older adults: The Atherosclerosis Risk in Communities (ARIC) study

Cognitive impairment is a major health concern affecting loss of independence in basic daily activities in older age and thus special attention should be devoted to its prevention. Recent research indicates that -3 fatty acids, prominent in foods of marine origin, may also be important in preventing cognitive decline. So far, epidemiological evidence, although inconclusive, leans towards a protective effect of increased -3 fatty acid intake in the diet. Experimental animal studies suggest a plausible pathway by which hypertension and low dietary -3 fatty acid intake may interact in increasing the risk of cognitive decline. The present study assessed the independent effect of low -3 fatty acid status on cognitive decline as well as the interaction of this risk factor with elevated blood pressure, as well as other factors associated with increased oxidative stress. The results of this study may have great public health and biomedical implications, particularly for prevention efforts among middle-aged adults. To this end, we conducted a secondary data analysis of the Atherosclerosis Risk in Communities (ARIC) study. This study initially recruited a probability sample of 15,792 men and women aged between 45 and 64 years from four distinct US communities, namely Jackson county (Mississippi), Forsyth county (NC), suburbs of Minneapolis (MN) and Washington county (MD). Follow-up visits were conducted after baseline period (1987-89, or visit 1) on three occasions, separated by a three-year interval. Our analyses focused on men and women aged 50 years or more at visit 1. We assessed cognitive decline using three screening tools measured at visits 2 and 4. Exposure is assessed at visit 1 both in the diet (using a food frequency questionnaire) and in plasma (phospholipids and cholesteryl ester fractions). However, plasma fatty acids were measured only for the white population of MN at visit 1. Using empirical equations derived from animal feeding studies and several biomarkers, true fatty acid intake was predicted as well as measurement error which was corrected for in multivariate logistic models, using regression calibration and SIMEX methods.Doctor of Philosoph