Scientists from the University of Washington have found that keeping the brain’s protective barrier healthy is one of the most important factors for maintaining good brain function as we age. This barrier, called the blood-brain barrier, is a network of blood vessels that helps control what enters and exits the brain.
After reviewing over 150 studies, the researchers discovered that leaks in the blood-brain barrier may contribute to memory problems. Normally, this barrier acts as a filter, preventing harmful substances in the blood from reaching the brain while allowing essential nutrients to pass through.
It also removes waste and toxins. When this system doesn’t work properly, it may contribute to conditions such as multiple sclerosis, diabetes, and Alzheimer’s disease.
The study found that small leaks in the blood-brain barrier are common in healthy aging. These minor changes may be linked to mild forgetfulness, which most scientists consider a normal part of aging. However, in people with a genetic risk factor for Alzheimer’s disease, known as the ApoE4 gene, these leaks tend to happen more quickly and more severely.
People with the ApoE4 gene also have a harder time clearing a substance called amyloid beta-peptide from their brains. This leads to a buildup of plaques, which are strongly linked to Alzheimer’s disease. Even in normal aging, the brain’s ability to remove this waste declines, but in Alzheimer’s, the process becomes even less effective.
The researchers also looked at how aging affects two important types of cells in the blood-brain barrier: pericytes and astrocytes. Pericytes help maintain the barrier’s strength, but they tend to decrease with age, especially in Alzheimer’s disease. Astrocytes, on the other hand, become overactive, which may contribute to further brain damage.
Some studies suggest that pericyte health can be preserved through habits that also extend lifespan, such as regular exercise, calorie restriction, and certain medications like rapamycin. This means that lifestyle choices could help keep the blood-brain barrier functioning properly and possibly reduce the risk of memory problems and dementia.
This research, led by Dr. William Banks, was published in Nature Aging. It highlights the importance of protecting the brain’s barrier to support memory and overall brain health as people get older.
If you care about brain health, please read studies about vitamin D deficiency linked to Alzheimer’s and vascular dementia, and higher magnesium intake could help benefit brain health.
For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and coconut oil could help improve cognitive function in Alzheimer’s.
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