A decade-long study has found that whole grains are linked to faster cognitive decline, despite being part of a popular and well-backed healthy diet. The study used repeated MRI scans of 1,647 adults to assess their diets and their adherence to the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. Those who scored higher on the MIND diet showed significantly slower loss of gray matter, the brain tissue responsible for processing sensory information, muscle control and decision-making. While berries and poultry were largely responsible for this positive effect, whole grains like oats and brown rice, as well as cheese, showed somewhat faster declines in grey matter. The findings suggest that these foods could be influenced by other habits of those who eat more cheese or grains.