The APP gene variant protecting against Alzheimer’s disease significantly decreases plasma beta-amyloid levels in a population cohort. This is a very significant discovery, as many on-going drug trials in the field of Alzheimer’s disease focus on decreasing beta-amyloid levels in the brain tissue. According to the study, a 30% life-long decrease in beta-amyloid levels is not associated with detrimental effects on lipid or glucose metabolism, or on any other metabolic factors.