“We were surprised by these results,” Dr. Schmidt said. “The reasons for this decreased risk are unclear, but it could be explained by missed diagnoses of shingles in people with undiagnosed dementia. Shingles vaccination is encouraged for older people because it can prevent complications from the disease, but our study suggests it is unlikely to reduce dementia risk.”
According to News Wise, the study was limited to participants who were treated for the disease. No study was completed for those with untreated shingles. And 0.1% of those with shingles were found to have nearly twice the risk of dementia, as the shingles virus had affected their central nervous systems.