Alzheimer's disease (AD) is a progressive, irreversible neurodegenerative disorder and a major health alarm worldwide, characterized by cognitive decline, neuronal dysfunction, and memory impairment. The relevance of nutrition toward AD is limited; therefore, this review explores how nutrition may help prevent cognitive decline in the early stages of AD, emphasizing dietary patterns and key nutrients. Early diagnosis is crucial, as numerous complications characterize the later stages. The current therapeutics can only suppress the progression; therefore, nutrition-based therapeutic approaches have emerged as an alternate and pivotal strategy to mitigate cognitive decline in early-stage AD patients. The disease has complex pathology; therefore, early diagnosis and the role of biomarkers are very important and warrant further exploration. Although there is no specific diet that could prevent or cure AD, an increasing number of studies show that nutrition plays an important role in maintaining the function of the brain and slowing neurodegeneration. Consequently, switching to a healthy diet along with a better lifestyle may contribute to the prevention of neurodegeneration and reduce the risk of AD in the future. Therefore, this review highlights the dietary patterns and key nutrients that may help prevent or minimize the impact of AD. Additionally, it examines case studies and explores future research directions, thereby emphasizing the role of a healthy diet as a complementary therapeutic approach.