According to a new study in mice, a probable cause of Alzheimer’s disease is the leakage from blood into the brain of fat-carrying particles transporting toxic proteins. Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer’s disease. In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for Alzheimer’s disease...