As people grow older, many worry about memory loss and changes in thinking. These changes often happen slowly and quietly, long before any clear signs of dementia appear.
Scientists have been trying to understand why some older adults stay mentally sharp while others begin to struggle with memory and attention.
A large new study suggests that the answer may lie not only in the brain itself, but also in the health of the blood vessels that supply it.
Researchers involved in a large clinical study called IGNITE looked closely at a condition known as arterial stiffness. Arteries are the large blood vessels that carry blood from the heart to the rest of the body.
When we are young, these vessels are flexible and can easily absorb the pressure of each heartbeat. As we age, arteries often become stiffer and less elastic. This makes it harder for them to cushion blood flow, placing extra stress on the heart and reducing the steady delivery of oxygen and nutrients to organs, especially the brain.
The IGNITE study included 570 older adults who showed no signs of dementia or serious thinking problems. All participants were considered cognitively healthy. The researchers wanted to understand whether changes inside the body could still affect thinking skills, even before noticeable symptoms appeared.
One key focus of the study was a blood marker called neurofilament light chain, often shortened to NfL. This substance enters the blood when nerve fibers in the brain are damaged.
NfL levels naturally increase with age, but unusually high levels may point to faster brain aging or higher risk of future memory problems. By measuring NfL in blood samples, scientists can get clues about what is happening inside the brain without invasive tests.
The researchers also measured arterial stiffness using a standard test that looks at how quickly blood pressure waves move from the heart to the lower body. Faster movement means stiffer arteries. This test has long been used to study heart health, but it is now gaining attention for its possible role in brain aging.
When the researchers compared all of this information, a clear pattern emerged. Older adults with stiffer arteries tended to perform worse on certain thinking tasks. These included remembering past events, holding information in mind, and quickly processing new information.
The effects were even stronger in people who had both stiff arteries and higher levels of NfL. In this group, signs of nerve fiber damage were much more closely linked to memory difficulties.
This suggests that stiff arteries may make the brain more vulnerable to damage. In other words, when blood vessels lose their flexibility, the brain may struggle more to cope with normal age-related wear and tear. Even small injuries to nerve fibers may have bigger effects when blood flow is less steady and supportive.
The researchers stress that this study does not prove that arterial stiffness directly causes memory loss. Because the study looked at people at a single point in time, it can only show links, not cause and effect.
Still, the findings raise important questions. If stiff arteries make brain damage more harmful, then improving blood vessel health could potentially slow or reduce cognitive decline.
Experts involved in the study believe this work highlights the close connection between heart health and brain health.
The brain depends on healthy blood vessels to function properly. Conditions like high blood pressure, high cholesterol, and diabetes are already known to harm arteries. This study suggests that managing these conditions may also help protect memory and thinking skills.
The findings also support the idea that brain aging is influenced by multiple factors working together. Nerve damage alone does not tell the full story. Blood vessel health plays a key role in determining how well the brain can cope with that damage. When both problems exist at the same time, the risk to thinking abilities appears to be higher.
The IGNITE study is part of a larger effort to understand how lifestyle choices, especially physical activity, affect brain health in older adults.
The trial is testing whether different levels of aerobic exercise can improve brain structure, blood markers, and thinking skills. Future research may reveal whether exercise or other treatments can reduce arterial stiffness and protect the brain.
In reviewing these findings, it becomes clear that cognitive decline is not caused by a single issue. Instead, it appears to be the result of several aging processes interacting over time. This study adds strong evidence that vascular health is a critical piece of the puzzle.
While more research is needed, the results suggest that protecting blood vessels may help reduce the impact of brain aging and delay memory decline. Paying attention to both brain markers and heart health could help doctors identify people at higher risk earlier and design better ways to protect cognitive function as we age.
If you care about dementia, please read studies about Vitamin B9 deficiency linked to higher dementia risk, and flavonoid-rich foods could help prevent dementia.
For more information about brain health, please see recent studies that cranberries could help boost memory, and how alcohol, coffee and tea intake influence cognitive decline.
The study is published in Alzheimer’s & Dementia.
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