Recent research indicates a potential connection between shingles—a virus affecting about a million Americans annually—and an increased risk of developing dementia, specifically Alzheimer’s disease. A study from Stanford University revealed that individuals who received the shingles vaccine were 20 percent less likely to develop dementia later on. This emerging field of research explores how various viruses, including those that cause chickenpox and herpes, may contribute to Alzheimer’s disease, opening new avenues for understanding this complex disorder.
Shingles are caused by the varicella-zoster virus, which remains dormant in the nervous system after an individual has chickenpox. As people age or experience health challenges, the virus can reactivate, leading to shingles. While the exact triggers for reactivation are still unclear, it is believed that a weakened immune system plays a significant role. The Centers for Disease Control and Prevention (CDC) estimates that shingles affect approximately one million Americans each year, while Alzheimer’s disease sees about 500,000 new diagnoses annually in the U.S.
Dr. Pascal Geldsetzer’s study, which is yet to undergo peer review, analyzed health records of around 300,000 individuals born in Wales between 1925 and 1942, comparing those who received the shingles vaccine to those who did not. The researchers noted a 20 percent reduction in the risk of developing dementia among vaccinated individuals within seven years of receiving the shot. To validate their findings, the team extended their analysis to the United Kingdom and Australia, uncovering similar trends in those regions.
In parallel, researchers at Oxford University supported these findings through a 2024 study that examined health records of 200,000 Americans who received a newer shingles vaccine called Shingrix. This research revealed a 17 percent decrease in dementia risk over six years for those vaccinated compared to individuals who had received older vaccines. Experts believe that the long-term benefits of vaccination may extend beyond immediate health outcomes, highlighting a potential avenue for preventing dementia.
Although the mechanism linking shingles to dementia remains unclear, some researchers hypothesize that the dormant virus may disrupt blood flow to the brain when reactivated, especially in older adults. This disruption could lead to stress on brain cells over time, potentially increasing dementia risk. Scientists like Dr. Maria Nagel emphasize the importance of this research, noting that it introduces fresh perspectives into Alzheimer’s studies and could lead to significant advancements in understanding and addressing the disease in the coming years.
