From plate to brain: benefits, deficiencies, and research needs of plant-based diets

In recent years, plant-based diets and their specific components have gained popularity across all age groups and have attracted growing interest in the scientific community due to their potential health benefits. While these benefits have been extensively studied concerning overall health, their impact on cognitive performance and brain structure remains less understood. At the same time, concerns have been raised about the potential risk of nutritional deficiencies associated with plant-based diets. Given these uncertainties and gaps in the literature, it is crucial not only to recognize the potential benefits but also to address the possible drawbacks of plant-based eating. Moreover, little is known about the role of specific plant-derived components in brain function and structure, as well as the most effective strategies to mitigate potential risks. Special attention is given to the modulatory role of the gut microbiota, short-chain fatty acids, and neuroinflammation. Moreover, this review identifies critical gaps in research involving younger individuals and populations from low- and middle-income countries, where dietary transitions and nutritional deficiencies pose unique risks. Therefore, this review provides a novel perspective by critically integrating evidence on the benefits and risks of plant-based diets, encompassing brain structure, cognitive function, and potential bidirectional neurochemical pathways via the gut-brain axis, while highlighting implications across different life stages and underrepresented populations.