This is one outlet's own report from Newsweek — the article as it was filed. Other outlets are covering the same event; open the full story to compare every source side by side.
Overlooked Body Function May Predict Faster Alzheimer's, Study Finds
0 Share Newsweek is a Trust Project member See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. An often-overlooked measure of physical health may help predict faster brain shrinkage in people who carry a major genetic risk factor for Alzheimer's disease, according to a new study.
Researchers followed hundreds of older adults for more than a decade and found that those at elevated genetic risk for Alzheimer's showed greater signs of brain volume loss over time when cardiac output, a measure of how much blood the heart pumps, was lower. The effect was particularly evident in brain regions associated with the disease.
The Vanderbilt Health study found that lower cardiac output was linked to accelerated brain atrophy among people who carry the APOE-e4 gene variant, a known genetic risk factor for Alzheimer's disease.
The study, published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association , followed 756 adults aged 50 to 92 for up to 11 years. Researchers wanted to determine whether reduced heart function could affect brain health even in people without diagnosed cardiovascular disease.
They found that among APOE-e4 carriers, lower cardiac output at the start of the study was associated with smaller overall brain volume, as well as smaller temporal and occipital lobe volumes. Over time, lower cardiac output also predicted greater shrinkage of the temporal lobe, a brain region implicated in Alzheimer's disease .
"This study is among the first and largest to examine the impact of subclinical cardiac dysfunction on neurodegeneration over time, and among the first to evaluate how APOE-e4 status modifies these associations," first author Dr. Elizabeth Moore said in a statement.
The findings add to growing evidence that factors beyond genetics may influence the development and progression of Alzheimer's disease.
Dr. Alan Farrell, chief medical officer at Choose Health, who was not involved in the study, told Newsweek the research strengthens a broader trend emerging in Alzheimer's research.
"The significance of this evidence comes from the fact that it provides yet another confirmation of a conclusion that has been slowly building over recent years, namely that Alzheimer's disease cannot be explained solely in terms of genes," Farrell said.
He noted that the study found an association rather than proving that reduced cardiac output directly causes brain shrinkage.
"Although this kind of study demonstrates an association rather than providing evidence that lower cardiac output directly results in brain atrophy, it is an important step toward understanding risk, even if it does not establish causation," Farrell said.
The researchers drew their data from the Vanderbilt Memory and Aging Project, a long-running study designed to examine how vascular health contributes to brain aging. Participants underwent extensive testing, including blood draws, physical examinations, heart imaging and brain MRI scans, with follow-up assessments conducted regularly across the study period.
According to the researchers, the results suggest that even mild declines in heart function may have important implications for brain health among people already at elevated genetic risk of Alzheimer's disease.
"Our findings suggest that even subtle reductions in cardiac function may have important implications for brain health, particularly among individuals at increased genetic risk for Alzheimer's disease," Moore said.
Farrell said the results reinforce the long-recognized connection between the cardiovascular system and the brain.
"Cardiovascular health and brain health have long been recognized as being closely linked through shared mechanisms involving blood flow, vascular integrity, and metabolic homeostasis across both organ systems," he said.
Because the brain has limited energy reserves, Farrell said it is biologically plausible that long-term reductions in heart performance could affect brain structures involved in cognition, especially in those with a genetic predisposition.
At the same time, he cautioned that important questions remain unanswered.
"A major limitation is that observational studies cannot determine causation," Farrell said.
"It is not known whether decreased cardiac output leads to brain atrophy, whether both events are downstream of another mechanism, or whether the relationship varies across different age groups, between men and women, or in individuals with other cardiovascular risk factors."
He added that researchers still need to determine whether the observed pattern is unique to APOE-e4 carriers or might also occur in the wider population.
The study authors said their findings support a precision medicine approach, in which genetic information is used to tailor prevention and screening efforts. In their summary, they suggested periodic cardiac screening could potentially become an important prevention strategy for people carrying the APOE-e4 variant.
Looking ahead, Farrell said future research should focus on whether maintaining cardiovascular health can meaningfully influence brain aging in people with elevated genetic risk.
"The next step is to determine whether preserving cardiovascular health has any clinically relevant impact on brain aging in individuals at higher genetic risk," he said.
"Future studies should systematically address whether changes in cardiac function over time are linked with slower brain atrophy or improved cognitive outcomes through long-term prospective studies and well-designed clinical trials."
He added that combining advanced brain imaging with cardiovascular and metabolic biomarkers could help researchers better understand how heart, vascular and brain health interact throughout life.
Moore et al. Lower cardiac output is a risk factor for faster cerebral atrophy over a 11-year follow-up period in APOE-ε4 carriers. DOI: https://doi.org/10.1002/al...
AIPROPX is an independent multi-source news index — we track, compare, and connect coverage from across the web into one place you won't find anywhere else.
