15. margarine
Many people mistakenly think that they make a good healthy decision when they opt for the buttered margarine with which to bake or put their toast in the morning. But when it comes to the health of your brain, margarine is as bad for you as butter. This is because of the agglutination of beta-amyloid protein, one of the hallmarks of Alzheimer's disease. Researchers believe that margarine can increase the toxic effects of beta-amyloid on the brain, resulting in memory loss and Alzheimer's disease.