Your brain has a special defense system called the blood-brain barrier. This network of tiny blood vessels controls what can enter the brain from the bloodstream.
It keeps out harmful substances while allowing in nutrients the brain needs to function properly.
This barrier also helps remove waste from the brain, playing a key role in keeping your mind sharp and healthy.
But as we get older, this barrier starts to weaken.
Scientists at the University of Washington recently reviewed over 150 studies to understand how changes in the blood-brain barrier may affect memory and brain health during aging.
Their findings, published in the journal Nature Aging, show that even small leaks in the barrier can have a noticeable effect on memory. These leaks are a normal part of aging, but they can also contribute to more serious conditions like Alzheimer’s disease.
In healthy older adults, these tiny leaks in the blood-brain barrier are linked to mild forgetfulness that comes with age. This is different from dementia—it’s more about occasionally misplacing your keys or forgetting a name.
But in people with a certain gene called ApoE4, these leaks can be much worse. ApoE4 is known to increase the risk of Alzheimer’s disease, and it also makes it harder for the brain to clear out a sticky protein called amyloid beta. This protein can build up and form plaques in the brain, which are a hallmark of Alzheimer’s.
Normally, the blood-brain barrier helps remove amyloid beta. But as we age—and especially in people with Alzheimer’s—the barrier becomes less effective. This means the brain can’t clear out waste as well, and toxic substances may leak in, making things worse.
The researchers also looked at two types of cells that are key to the health of the blood-brain barrier: pericytes and astrocytes. Pericytes help keep the barrier strong and secure, but they become fewer with age, especially in people with Alzheimer’s.
Astrocytes, another kind of support cell, tend to become overactive as we get older. This overactivity may actually worsen the leaks in the barrier.
The good news is that some simple lifestyle choices may help protect these important cells and keep the blood-brain barrier working better for longer. Regular exercise, eating fewer calories, and possibly even certain medications (like rapamycin, which has shown promise in animals) may help support pericyte health and maintain the barrier’s strength.
These protective effects could help delay memory loss and reduce the risk of brain diseases.
The blood-brain barrier is also involved in other health problems. When it doesn’t work well, it may play a role in conditions like multiple sclerosis and diabetes. So, keeping this barrier healthy is not just about aging—it’s about overall brain health.
This growing body of research shows how closely linked brain health is to the rest of the body. Things like staying physically active, eating a healthy diet, and maintaining a healthy weight don’t just help your heart and muscles—they also support your brain by protecting this vital barrier.
Dr. William Banks, who led the study, believes that understanding how the blood-brain barrier changes over time can help us find new ways to protect our memory and prevent diseases like Alzheimer’s. While more research is still needed, it’s clear that taking care of your body as a whole can help protect your brain too.
In the end, the message is simple: good health habits don’t just help you feel better now—they may also protect your brain as you age.
If you care about Alzheimer’s disease, please read studies about the protective power of dietary antioxidants against Alzheimer’s, and eating habits linked to higher Alzheimer’s risk.
For more health information, please see recent studies that oral cannabis extract may help reduce Alzheimer’s symptoms, and Vitamin E may help prevent Parkinson’s disease.
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