Sylvia also began incorporating other health foods, including broccoli, kale, spinach, sunflower seeds, green tea, oats, sweet potatoes and even dark chocolate with a high percentage of cacoa. All of these foods are known to be beneficial for brain health. Mark and Sylvia devised to diet together after deciding that the medication on it's own was not enough, they looked into the research showing that rates of dementia are much lower in mediterranean countries and copied a lot of their eating habits.