Accumulating evidence shows nutritional factors influence the risk of developing Alzheimer's disease (AD) and its rate of clinical progression. Dietary and lifestyle guidelines to help adults reduce their risk have been developed. However, the clinical dementia picture remains complex, and further evidence is required to demonstrate that modifying nutritional status can protect the brain and prevent, delay, or reduce pathophysiological consequences of AD. Moreover, there is a pressing need for further research because of the global epidemic of overweight and obesity combined with longer life expectancy of the general population and generally observed decreases in body weight with aging and AD. A new research approach is needed, incorporating more sophisticated models to account for complex scenarios influencing the relationship between nutritional status and AD. Systematic research should identify and address evidence gaps. Integrating longitudinal epidemiological data with biomarkers of disease, including brain imaging technology, and randomized controlled interventions may provide greater insights into progressive and subtle neurological changes associated with dietary factors in individuals at risk for or living with AD. In addition, greater understanding of mechanisms involved in nutritional influences on AD risk and progression, such as oxidative stress and loss of neuronal membrane integrity, will better inform possible interventional strategies. There is consensus among the authors that nutritional deficits, and even states of excess, are associated with AD, but more work is needed to determine cause and effect. Appropriately designed diets or nutritional interventions may play a role, but additional research is needed on their clinical-cognitive effectiveness.
