The herpes simplex virus is a common virus, affecting around 67% of the global population under 50 years old. The virus is a lifelong infection and often has either mild or no symptoms. It can be detected via the presence of antibodies in the blood. So far, studies have delivered conflicting results as to whether prior herpes infection affects dementia risk.
In the current study, researchers investigated the potential link between antibodies for herpes and the incidence of dementia and Alzheimer's disease. To do so, they recruited 1002 dementia-free 70-year-olds living in Sweden and followed them for 15 years. 82% of the participants carried herpes antibodies, of whom 6% had previously received anti-herpes virus treatment.
Ultimately, they found that 4% and 7% of the participants developed Alzheimer's disease or dementia. Herpes antibodies were linked to a more than doubled dementia risk. However, no link was found for Alzheimer's disease. They noted that the relatively low incidence of Alzheimer's disease in their cohort may have limited statistical power to detect associations with the condition.
"It is exciting that the results confirm previous studies. More and more evidence is emerging from studies that, like our findings, point to the herpes simplex virus as a risk factor for dementia," said study author Erika Vestin, a medical student at Uppsala University, in a press release.
"The results may drive dementia research further towards treating the illness at an early stage using common anti-herpes virus drugs, or preventing the disease before it occurs," she added.
Sources: Science Daily, Journal of Alzheimer's Disease