Alzheimer’s disease (AD) is the most prevalent cause of dementia worldwide. Treatments achieving a

marked improvement in symptoms or preventing or delaying the progression of the disease are not

available. Various diet-related risk factors for AD have been identified. Evidence for a protective effect of

the Mediterranean diet on AD risk is inconclusive. Medical foods are designed to meet specific dietary

needs for certain diseases. Improvements in symptomatology and regional brain atrophy in AD have been

claimed for several medical foods, for example, those providing ketone bodies as alternative energy supply

to neurons, those containing precursors believed to improve synaptic function, and those addressing

oxidative stress related to memory loss. Many methodological shortcomings render the interpretation of

the available findings of medical food trials in AD difficult. Optimal results of medical foods in AD may be

expected when administered in presymptomatic or early stages of the disease. This requires the reliable

identification of minimal neuropathological changes related to AD. The outcome measures currently used

may not be able to detect subtle changes in cognition and function in early AD. Large-scale clinical studies

using valid, sensitive, and reliable assessment tools are needed to establish the efficacy of medical foods

in AD.