New Research Links Shingles to Mental Decline

The study published on Tuesday is the latest to suggest that the viral disease shingles may be harmful to our long-term brain health. Scientists have shown that people who had shingles were about 20% more likely to experience cognitive decline afterward. The findings seem to bolster the growing idea that the shingles vaccine may protect against dementia.

Shingles is caused by the varicella zoster virus (VSV), the same virus that causes chickenpox in children and adults. After someone recovers from the chicken pox, the virus will usually be able to survive and lie dormant within our nervous system. Years, often decades later, about one-third of chickenpox cases will develop a recurrent infection of the virus, known as shingles. Shingles is no picnic, often causing severe pain, rashes, and other symptoms for up to five weeks. Some people will also have chronic nerve pain that can last for years.

Some research has suggested that VSV and other viruses that lurk in the brain can cause subtle neurological damage, particularly an increased risk of Alzheimer’s disease and dementia. But this remains controversial and other studies have failed to support such a connection. Scientists at Brigham and Women’s Hospital led the new study, hoping to better resolve any possible relationship between shingles and worsening brain health.

The researchers analyzed data from three large previous studies that prospectively followed the long-term health of nurses and health care professionals (these are known as prospective studies). As part of these studies, people were asked regularly about their mental health and whether they had ever had shingles. In total, about 150,000 people were included in their analysis.

Those who reported having shingles were more likely to report some cognitive decline, the researchers found. Even after accounting for other factors, they found that having shingles was associated with a 20% higher risk of cognitive decline in men and women alike. The corresponding risk was higher in men who also carried the gene APOE4a common genetic variation that has been known to raise the risk of Alzheimer’s. Their findings were published Tuesday in the journal Alzheimer’s Research & Therapy.

This study alone cannot prove a causal link between shingles and cognitive decline, but it is the latest piece of supporting evidence. In late July, for example, UK scientists found that people given Shingrix, the newest shingles vaccine, were less likely to develop dementia over a six-year period, even compared to people given an earlier, less potent shingles vaccine. . Shingrix is ​​already very successful in its main function, providing more than 90% protection against shingles for at least seven years. An earlier study by a team at Brigham and Women’s Hospital also showed that shingles may increase the risk of long-term cardiovascular disease. So given that and these recent findings, researchers say preventing shingles may be more important than currently thought.

“Our findings show the long-term effects of shingles and highlight the importance of public health efforts to prevent and promote the uptake of the shingles vaccine,” said researcher Sharon Curhan, an assistant professor of medicine at Brigham and Women’s Hospital, in a statement from the hospital. “Given the growing number of Americans at risk of this painful and often disabling disease and the availability of a highly effective vaccine, shingles vaccination may provide an important opportunity to reduce the burden of shingles and possibly reduce the burden of subsequent cognitive decline.”

Because of how common chickenpox was, about one in three Americans over the age of 50 is expected to get shingles in their lifetime without vaccination. So considering how painful the experience can be, preventing shingles with two simple shots is easy to take—and possibly keeping your brain sharp as you get older is just the cherry on top.