Prevention of Late-life Cognitive Disorders: Diet-Related Factors, Dietary Patterns, and Frailty Models

Abstract

The need for preventing or postponing the onset of Alzheimer’s disease (AD) and delaying or slowing its progression is a direct consequence of the current symptomatic approach of existing drugs for the treatment of AD. Dietary factors may affect the risk of AD and dementia, with a substantial body of evidence suggesting that certain diets have been associated with a lower incidence of AD and late-life cognitive disorders. Among healthy diets, higher adherence to a Mediterranean-type diet and to the Dietary Approaches to Stop Hypertension diet was associated with decreased cognitive decline, although the Mediterranean diet (MeDi) combines several foods, micro-, and macronutrients already separately proposed as potential protective factors against dementia. Higher adherence to the MeDi was associated with a reduced risk of cognitive impairment, MCI, and AD, as well as the transition from MCI to AD, and decreased all-causes mortality in AD patients. Influencing some age-related conditions, such as frailty, may have an impact on the prevention of late-life cognitive decline. Frailty reflects a nonspecific state of vulnerability and a multisystem physiological change and it is a widely recognized risk factor for adverse health outcomes in older persons. At present, no operational definition has been established, although nutritional status, cognition, and mood have been proposed as markers of frailty. Physical frailty may be associated with late-life cognitive impairment/decline, incidence of AD, vascular dementia, non-AD dementias, and AD pathology in older persons with and without dementia, also suggesting the definition of cognitive frailty as a new clinical condition. The reviewed evidence supports the hypothesis that frailty could be important in the prevention of late-life cognitive disorders, and nutritional influences may be of major relevance. Nutritional interventions might be able to address the impaired nutrition and weight loss of frailty. There is a critical need for randomized, controlled trials investigating the role of nutrition on late-life cognitive disorders and frailty that might open new routes for the prevention and management of cognitive decline and AD, supplementing existing symptomatic approaches, also through the nutritional prevention of frailty.