Nutrition: A non-negligible factor in the pathogenesis and treatment of Alzheimer's disease

Abstract

Alzheimer's disease (AD) is a degenerative disease characterized by progressive cognitive dysfunction. The strong link between nutrition and the occurrence and progression of AD pathology has been well documented. Poor nutritional status accelerates AD progress by potentially aggravating amyloid beta (Aβ) and tau deposition, exacerbating oxidative stress response, modulating the microbiota-gut-brain axis, and disrupting blood-brain barrier function. The advanced stage of AD tends to lead to malnutrition due to cognitive impairments, sensory dysfunctions, brain atrophy, and behavioral and psychological symptoms of dementia (BPSD). This, in turn, produces a vicious cycle between malnutrition and AD. This review discusses how nutritional factors and AD deteriorate each other from the early stage of AD to the terminal stages of AD, focusing on the potential of different levels of nutritional factors, ranging from micronutrients to diet patterns. This review provides novel insights into reducing the risk of AD, delaying its progression, and improving prognosis. HIGHLIGHTS: Two-fifths of Alzheimer's disease (AD) cases worldwide have been attributed to potentially modifiable risk factors. Up to ≈26% of community-dwelling patients with AD are malnourished, compared to 7%∼76% of institutionalized patients. Undernutrition effects the onset, progression, and prognosis of AD through multiple mechanisms. Various levels of nutritional supports were confirmed to be protective factors for AD via specific mechanisms.

Keywords: Alzheimer's disease; cognition; diet pattern; nutrition.

FIGURE 1

The vicious circle among Alzheimer's disease (AD) development and undernutrition. Created with BioRender.

FIGURE 2

Features and different emphases of MeDi, DASH and MIND. Created with BioRender. DASH, dietary approaches to stop hypertension; MeDi, Mediterranean diet; MIND, Mediterranean‐DASH intervention for neuro‐degenerative delay.