Official estimates have blamed Alzheimer’s disease (AD) for the deaths of about 85,000 Americans each year, but new research suggests the true number of AD deaths may be closer to 500,000 annually. In a study that tracked about 2,600 initially healthy older adults for eight years, scientists found that more than a third of fatalities among participants over 75 were associated with the neurodegenerative disease. The researchers found that 22 percent of participants eventually developed AD, 72 percent of whom died. In contrast, just 34 percent of dementia-free participants died over the course of the study.
The deaths appear to be linked to impairment over time of the brain’s ability to control heart rate and breathing, the researchers reported. The strikingly higher AD death toll indicated by the study, which was published in the March 5, 2014 online edition of Neurology, boosts AD to a rank among the top killers of older Americans that rivals heart disease and cancer. An estimated 5 million Americans over the age of 65 suffer from AD. Deaths among these individuals are often blamed on an immediate cause, such as pneumonia, which is actually the result of underlying breathing and swallowing problems associated with AD.