Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects millions in the aging population worldwide and will affect millions more in the next 20 years. Over 90% of all cases are sporadic, with genetics playing a minor role in the etiology of AD. Therefore, it is crucial to investigate the environment and diet as primary risk factors in AD pathology. This review considers epidemiologic case control studies, and in vitro and in vivo research to investigate the potential of environmental exposure to metals, air pollution and pesticides as well as diet as risk factors for AD. In some cases, the role of genetic mutations and environmental risk is discussed. The evidence examined in this review provides a brief overview of the current literature on selected, significant risk factors in promoting amyloid-beta accumulation and aggregation, thus contributing to neurodegeneration.