Does aging change docosahexaenoic acid homeostasis? Implications for the challenge to cognitive health in the elderly

Cognitive health in the elderly is an increasingly important preoccupation for public health institutions globally. This preoccupation is all the more acute given the lack of effective medical treatment for the various types of cognitive decline associated with aging including ‘‘Alzheimer’s disease’’. Because the various forms of cognitive decline in the elderly are increasingly recognised as a heterogeneous conditions (Whitehouse et al., 2011), we prefer the general term aging-related cognitive decline (ARCD). Conditions linked to the metabolic syndrome, particularly insulin resistance and type 2 diabetes, are major risk factors for cognitive decline in the elderly (Hao et al., 2011). Since the metabolic syndrome is preventable at least in adolescents and younger adults, in theory, prevention should be able to play a key role in the reducing the risk of ARCD. Nutrition and physical activity are key elements of prevention in reducing the susceptibility to themetabolic syndrome and type 2 diabetes.Omega-3 fatty acids such as docosahexaenoic acid (DHA) are amongst the nutrients of particular interest relative to optimal glucose metabolism, especially for cognition (Cunnane et al., 2009; Pifferi et al., 2010; Cunnane et al., 2011).