Two new NIH-supported studies have shown that a person’s epigenome—the chemical modifications, or marks, on our DNA that turn gene activity on and off—may influence Alzheimer’s disease-related changes in the brain. The two groups of researchers examined brain tissue donated by volunteers with Alzheimer’s and those free of the disease and linked a specific epigenome marker, DNA methylation, with Alzheimer’s pathology in the brain.
Preliminary findings from a study by National Institute on Aging (NIA) scientists and colleagues showed that a blood test for Alzheimer’s-related proteins may accurately predict who might be at risk for the disease years before symptoms develop. The test measured the levels of several tau and amyloid proteins—the hallmarks of Alzheimer’s disease—in exosomes, microscopic organelles shed by brain cells.
Physical activity may help prevent atrophy of the hippocampus, a brain region important for learning and memory that often shrinks in the brains of people with Alzheimer’s disease. A recent study that looked at the rate of atrophy over 18 months in cognitively normal older adults suggests that physical activity may help prevent or delay this Alzheimer’s-related change.
Teams of scientists will use support from the National Institutes of Health to conduct research into the genetic underpinnings of Alzheimer’s disease, analyzing how genome sequences—the order of chemical letters in a cell’s DNA—may contribute to increased risk or protect against the disease.
Scientists have discovered gene variants that affect the function of immune cells in young, healthy people. Interestingly, many of these same gene variants are known risk factors for diseases that occur later in life, including Alzheimer’s and Parkinson’s. This linking of known gene risk factors for age-related neurological disorders to immune system functions, such as inflammation, offers new insights into Alzheimer’s and other disorders and may one day lead to promising therapies.
Official mortality figures may have substantially underreported deaths due to Alzheimer’s disease in 2010 show two recent studies supported in part by NIA. Underreporting of Alzheimer’s as a cause of death on death certificates is a well-known phenomenon. Some people with the disease never receive a diagnosis. Many others have dementia-related conditions, such as aspiration pneumonia, listed as the primary cause of death while the underlying cause, Alzheimer’s, is never reported.