The Nutrition for Dementia Prevention working group was formed in 2020 by an international group of experts to address the following paradox: observational studies reveal an association between a healthy diet or dietary components and better brain health, but clinical trials investigating healthy diets or supplements have not shown convincing clinical benefit. Over the past two years, the working group examined the limitations of existing trials and provided a roadmap for designing newer studies and trials that can address past limitations and move the field forward. We thank the National Institute on Aging at NIH and the Alzheimer Association for supporting this work. A symposium was held in July of 2021 to debate these findings. The proceedings of this symposium are now published in Lancet Healthy Longevity