Scientists at the University of Washington have discovered that keeping the brain healthy as we age depends a lot on something called the blood-brain barrier.
This is a special system of tiny blood vessels that acts like a filter. It protects the brain by keeping harmful substances in the blood from getting into the brain, while allowing important nutrients to pass through.
This barrier is not just a wall. It also works actively, letting in good substances like oxygen and vitamins, while removing waste and toxins from the brain. But as we get older, this system can start to break down. The researchers looked at over 150 studies and found that in older adults, even those who seem healthy, the barrier can become a little leaky.
These leaks may not cause big problems right away, but they may explain the small memory slips that many people experience as they age. More importantly, these small leaks could lead to more serious memory issues over time.
One group at higher risk is people who carry a genetic variant called ApoE4. This gene is the biggest known risk factor for Alzheimer’s disease. People with this gene tend to have a weaker blood-brain barrier as they age.
This makes it harder for their brains to get rid of a sticky protein called amyloid beta. When amyloid beta builds up, it forms plaques in the brain, which are a key sign of Alzheimer’s.
The review also looked at two types of brain cells that are part of the blood-brain barrier: pericytes and astrocytes. As people age, pericytes—cells that help keep the barrier strong—start to disappear, especially in people with Alzheimer’s.
When there are fewer pericytes, the barrier gets weaker and more leaky. At the same time, astrocytes, which normally support the brain, can become too active. This may cause more problems in the aging brain.
The good news is that some lifestyle choices may help protect these cells and keep the barrier healthier for longer. Studies show that regular exercise, eating fewer calories, and possibly a drug called rapamycin may help support pericytes and slow down brain aging.
This research reminds us that keeping the brain healthy means taking care of the whole body. Things like staying active, eating well, and avoiding unnecessary medications might not only protect your heart and body but also your brain.
This major study was published in the journal Nature Aging and led by Dr. William Banks. It adds to growing knowledge that the health of the blood-brain barrier plays a big role in memory and thinking. Paying attention to it may help keep our minds sharp as we get older.
If you care about dementia, please read studies about dietary strategies to ward off dementia, and how omega-3 fatty acids fuel your mind.
For more health information, please see recent studies about Choline deficiency linked to Alzheimer’s disease, and what to eat (and avoid) for dementia prevention.
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