DIETARY PATTERNS AND THEIR ASSOCIATION WITH ALZHEIMER’S DISEASE RISK AND PREVENTION: A SYSTEMATIC REVIEW

Andrelin Panya S. Fetiza; Jweety Ensalada; Melliz Cecilia R. Ecija; Gecelene C. Estorico

doi:10.5281/zenodo.21358387

Abstract

Alzheimer's disease (AD) is a rapidly escalating global public health concern with limited pharmacological treatments, highlighting the critical importance of identifying modifiable lifestyle risk factors. This systematic review evaluates the association between major dietary patterns and the risk, prevention, and progression of AD, alongside their underlying biological mechanisms. Adhering strictly to PRISMA guidelines, a comprehensive search of literature published between 2016 and 2026 was conducted across PubMed, Web of Science, Scopus, Cochrane Library, and ScienceDirect. Out of 494 records initially identified, 11 studies were selected for qualitative synthesis, with 6 studies ultimately qualifying for quantitative analysis. The findings indicate that traditional dietary patterns emphasizing whole, minimally processed foods demonstrate robust neuroprotective benefits. The Mediterranean diet showed the strongest, most consistent evidence for reducing cognitive decline and lowering AD risk. The MIND and plant-based diets also demonstrated favorable protection, though poorly planned plant-based diets carry risks of essential micronutrient deficiencies. Meanwhile, the DASH diet's benefits appear largely mediated through indirect cardiovascular improvements. In contrast, the ketogenic diet yielded mixed, inconclusive evidence due to small sample sizes and poor long-term adherence, despite its therapeutic potential to counter impaired cerebral glucose metabolism via ketone bodies. Conversely, Western dietary habits and diets rich in ultra-processed foods (UPFs) were strongly and consistently associated with accelerated neurodegeneration and heightened AD risk, driven by systemic inflammation, oxidative stress, and insulin resistance. Ultimately, dietary quality represents a vital modifiable target for dementia prevention. Public health strategies should actively promote anti-inflammatory, nutrient-dense dietary patterns while discouraging Western and ultra-processed options, though future research requires larger, long-term randomized controlled trials to establish direct causality.

Keywords

Alzheimer's disease; Dietary patterns; Mediterranean diet; Ultra-processed foods; Ketogenic diet; Neuroprotection; Systematic review

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