**5. Neurologic/neuropsychologic aspects**

In a *comprehensive* review of the literature on randomized clinical trials some evidence was found that vegetarian diets prevent or delay cognitive decline in elderly adults.

Some plant foods (citrus fruit, grapes, berries, cocoa, nuts, green tea and coffee) improve specific cognitive domains, most notably frontal executive functions [63].

A different conclusion can be reached by using a different review methodology when examining the literature. In a *systematic* review of the literature on the effects of plant-based diets on body and brain, no evidence was found for the putative effects of a plant-based diet. No causal relation was seen between the use of a plantbased diet and effects on cognitive functions, mental and neurological functioning, nor for any underlying mechanism [64].
