Alzheimer’s disease is recognized as a complex condition influenced by multiple factors, necessitating a similarly multifaceted approach to treatment. Ideally, interventions should prioritize averting the progression to dementia. Given the chronic nature of the disease, long-term management strategies are required. Within this framework, lifestyle modifications and dietary supplements emerge as appealing options due to their minimal toxicity, limited side effects, and cost-effectiveness. This study presents findings from a double-blind, placebo-controlled bicentric pilot clinical trial, demonstrating the significant cognitive preservation associated with genistein, a phytoestrogen found in soy and various other dietary sources, among individuals with prodromal Alzheimer’s disease. Our prior investigation utilizing APP/PS1 mice elucidated the specific mechanisms through which genistein operates, including anti-amyloid-β, antioxidant, anti-inflammatory, and antiapoptotic effects. These findings underscore the potential of identifying bioactive compounds from dietary sources for the management of Alzheimer’s disease.