The decline in cognitive function is generally the result of the complex interaction of several factors. First of all, age, but also demographic, educational, genetic, socio-economic, and environmental determinants, including nutrition. Cognitive decline and dementia prevalence are increasing, and they are projected to continue increasing in the next decades due to the aging of the world population. Currently, there are no effective pharmacological treatments for these devastating and disabling conditions, which emphasize the key role of preventive strategies. There is compelling evidence of the role of diet and lifestyle on cognitive function. Therefore, dietary/ nutritional approaches that contribute to prevent, or slow cognitive decline may have a remarkable public health impact. Numerous studies have explored the role of dietary components and patterns on age-associated cognitive decline, with accruing evidence that combinations of foods and nutrients can have synergistic effects beyond those attributable to individual foods or nutrients. Dietary patterns show the strongest evidence for slowing the development of cognitive decline, Alzheimer’s disease and other dementias including the Mediterranean diet, the Dietary Approaches to Stop Hypertension diet, and their combination (the MedDiet-DASH Intervention for Neurodegenerative Delay - MIND), among others with few positive results. There are also dietary patterns with no evidence of such effects. This review examines the evidence for the effects of some dietary patterns as neuroprotective with a potential to delay cognitive decline and the onset of dementia.