Over the past 50 years, major advances in the diagnosis and treatment of disease have dramatically increased human longevity. In many countries, average life expectancies have gone from less than 60 years to over 80 years.1 One statistic that puts such changes into perspective is that of all the people who have ever reached the age of 65, more than half are estimated to be alive today. But despite the increasing success in reducing the burden of human disease, there are exceptions to that general trend, as we discuss in this article.
In recent years the number of cases of dementia and other neurodegenerative disorders has risen significantly; it is projected to double every 20 years and reach 115 million worldwide by 2050.2 The most prevalent and rapidly increasing of the disorders is Alzheimer’s disease, which accounts for some 80% of dementia cases. Related conditions include Parkinson’s and...
