![NutritionFacts.org Video Podcast show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/072/375/small/nutritionfacts-org-video-podcast.jpg)
Summary: One week on a plant-based diet can significantly drop blood levels of homocysteine, a toxin associated with cognitive decline and Alzheimer’s disease. Without vitamin B12 supplementation, though, a long-term plant-based diet could make things worse.