Can diet modifications play a preventative role in the onset of Alzheimer’s disease?

Abstract

Alzheimer’s disease (AD) is a growing public health concern with potentially devastating effects. At present, there are no methods of prevention or any known cures for the disease. While genetic factors are relevant in early-onset cases, they are less relevant in late-onset sporadic AD, which is the most common form [1]. Research seeking to find drugs to slow its progression may pay off – someday. However, as the disease typically strikes very late in life, delaying its symptoms could be a good cure for many people. For example, it is now widely accepted that delaying the onset of the disease by even 5 years can cut its incidence in half. Indeed, clinical and epidemiological evidence points to lifestyle factors, including nutrition, as being crucial in delaying the onset of AD. Mounting evidence suggests that brain cells are remarkably responsive to what somebody is doing or eating. Among other nongenetic factors influencing AD, recent studies strongly support the hypothesis that certain dietary factors, such as the Mediterranean diet, may play a beneficial role in the relative risk for AD clinical dementia. Indeed, the effect of diet in AD has been an area of research that has produced enlightening results. More importantly, the evidence supporting a direct link between nutrition and AD neuropathology and dementia continues to grow, as the mechanistic pathways are defined and their biochemical functions scrutinized. Most remarkably, there is also evidence that high caloric intake in the form of saturated fat promotes AD-type neuropathology and, conversely, caloric restriction via reduced carbohydrate intake can prevent it. This evidence is very exciting and is consistent, in part, with current epidemiological studies, which suggest that obesity and diabetes are associated with a more than fourfold increased risk for developing AD. Clarifying the mechanisms through which certain dietary lifestyle factors and caloric intake may ultimately influence AD neuropathology will provide new avenues for the design of ‘therapeutic lifestyle strategies’ to treat AD, and possibly other neurodegenerative disorders.