Recent articles have reported a possible decline in dementia. What is causing it? Researchers examined data from more than 1500 brain autopsies to find out. The results could help scientists better understand the link between Alzheimer’s disease and cardiovascular health.
By Alzheimer's Prevention Bulletin
Recent medical publications have reported a decline in the number of new cases of dementia made each year (incidence of the disease). Others question whether a decline in incidence exists. But if there is a decline, what is causing it? You might wonder if it’s because fewer people have the telltale signs of Alzheimer’s disease – amyloid plaques and tau tangles in the brain. Yet a new study published in February 20 JAMA Neurology shows that there has not been a change in the incidence of this Alzheimer’s pathology.
Researchers examined autopsy data from two large longitudinal studies, The Rush Memory and Aging Project and the Religious Orders Study. Participants were divided into four birth groups ranging in year of birth from 1905 to 1930. The scientists found no differences in the prevalence of Alzheimer’s disease pathology (those plaques and tangles) among the groups. However, atherosclerosis (hardening and thickening of the arteries) was dramatically lower over time. The paper cites 54% of people born in 1905-1914 had moderate to severe atherosclerosis as compared to only 22% of those born in 1925-1930.
“While more research needs to be done to understand these findings, it’s important to know that people with dementia may have multiple brain issues,” said Geidy Serrano, PhD, Director of the Neuropathology Laboratory at the Brain and Body Donation Program at Banner Sun Health Research Institute in Arizona. “So even if someone has amyloid plaque and tau tangles in their brain, other issues such as thickening of the arteries could also contribute to their dementia.”
Thus, a decline in the incidence of atherosclerosis could account for a reduction in the prevalence of dementia. The researchers hypothesized that better cardiovascular health could increase resilience to the signature amyloid plaques and tau tangles associated with Alzheimer’s.
“The vascular system has a big impact on dementia,” said Dr. Serrano. “So, maintaining a healthy heart and vascular system through diet and exercise can reduce your chances of developing dementia due to Alzheimer’s.”
For more information on ways to maintain heart health, please see our February 2023 Alzheimer’s Prevention Bulletin “Maintain brain health with a healthy heart”. Additionally, you may be interested in watching videos from two experts at Banner Health as they discuss heart health and how it plays into your memory and thinking abilities.