Is the Mediterranean diet a feasible approach to preserving cognitive function and reducing risk of dementia for older adults in Western countries? New insights and future directions

• Adhering to a traditional Mediterranean diet has been shown to reduce the risk of developing MCI, AD and dementia, as well as non-clinical age-related cognitive decline.
• Adhering to the contemporary Western diet has been shown to increase risk for MCI, AD and dementia, as well as non-clinical age-related cognitive decline.
• The feasibility of a traditional Mediterranean diet intervention for older adults in Western countries is currently unknown.
• We review the question of whether it is feasible to encourage older adults with Western habitual dietary habits to adopt a traditional MedDiet pattern in its place, for greater age-related cognitive health.
• We address this question by critically appraising the scientific evidence behind both diets in relation to biological and socio-cultural factors.
• A novel biopsychosocial model is included which aims to synthesize all discussed topics together in a diagrammatic illustration.

The rise in the ageing population has resulted in increased incident rates of cognitive impairment and dementia. The subsequent financial and societal burden placed on an already strained public health care system is of increasing concern. Evidence from recent studies has revealed modification of lifestyle and dietary behaviours is, at present, the best means of prevention. Some of the most important findings, in relation to the Mediterranean diet (MedDiet) and the contemporary Western diet, and potential molecular mechanisms underlying the effects of these two diets on age-related cognitive function, are discussed in this review. A major aim of this review was to discuss whether or not a MedDiet intervention would be a feasible preventative approach against cognitive decline for older adults living in Western countries. Critical appraisal of the literature does somewhat support this idea. Demonstrated evidence highlights the MedDiet as a potential strategy to reduce cognitive decline in older age, and suggests the Western diet may play a role in the aetiology of cognitive decline. However, strong intrinsic Western socio-cultural values, traditions and norms may impede on the feasibility of this notion.