Researchers at the University of Missouri have identified a potential new method for protecting the brain against Alzheimer’s disease before symptoms appear. Their study indicates that rapamycin, a medication primarily used to prevent organ transplant rejection, can improve blood flow in the brains of middle-aged adults who carry a specific genetic risk factor.
The findings suggest that targeting circulation changes early could be a viable strategy for reducing the risk of dementia. The research adds to a growing body of work from the university aimed at understanding and preventing the most common form of dementia.
Rapamycin Targets APOE4 Carriers
The study was led by Ai-Ling Lin, a professor in the university’s School of Medicine. Her work focuses on identifying brain changes that occur before Alzheimer’s symptoms develop. A major part of her research involves the APOE4 gene variant, which is linked to a significantly higher risk of developing Alzheimer’s later in life.
People with the APOE4 variant often experience reduced blood flow in certain brain areas years before they notice memory difficulties. These circulation changes serve as an early warning sign. Lin’s previous work with mice carrying the APOE4 gene showed that rapamycin could slow brain aging and increase blood flow. This prompted the question of whether the drug would produce similar benefits in humans.
To test this, Lin and her team studied healthy adults between the ages of 45 and 65. The group included both APOE4 carriers and non-carriers. All participants received a low daily dose of rapamycin for four weeks. The results showed a clear difference between the two groups. Brain blood flow improved significantly among participants carrying the APOE4 gene. This benefit was not observed in those without the variant.
“If we can slow down aging in the brain for those people most at risk, maybe we can reduce the risk of them developing Alzheimer’s disease,” Lin said.
Women Show Greatest Improvement
Another key finding from the trial involves gender differences. Women carrying the APOE4 gene experienced the largest improvements in brain blood flow after treatment. This result is particularly relevant because women account for nearly two-thirds of people living with Alzheimer’s disease.
“We also found that females with APOE4 saw the greatest improvement in brain blood flow, which is significant given that nearly two-thirds of people with Alzheimer’s are women,” Lin noted. She described the results as an example of precision medicine, which tailors treatment to individual characteristics like genetics.
Rather than assuming a medication will work for everyone, researchers hope to identify the specific groups most likely to benefit. The collaborative environment at the Roy Blunt NextGen Precision Health building allowed scientists and medical professionals to move these laboratory findings into human studies more quickly.
While the study did not prove that rapamycin prevents Alzheimer’s or preserves memory over time, the improved circulation offers a promising direction for future research. More studies are needed to determine if these changes lead to lasting brain health improvements. The study was published in the Journal of Cerebral Blood Flow & Metabolism.
Source: ScienceDaily
