The herpes virus can double the risk of developing dementia – research – News

The herpes virus can double the risk of developing dementia

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Scientists have found out that the herpes virus can double the risk of developing dementia.

This is evidenced by the results of a long-term study published in the scientific journal Journal of Alzheimer’s Disease, writes Science Alert.

Scientists have studied the connection between herpes simplex virus type 1 (HSV-1) and the risk of developing dementia. For this, they analyzed the data of 2,000 70-year-old people in Sweden.

In this country, about 80% of adults carry antibodies to HSV-1, meaning their immune systems have been exposed to this infection at some point.

The hypothesis that infections could trigger some variants of Alzheimer’s disease was first proposed as early as 1907, but for many decades the scientific community ignored it and perceived it “with great hostility”.

In the 1990s, fragments of HSV-1 DNA were first detected in the brains of deceased Alzheimer’s patients. And in 2008, scientists found out that HSV-1 is present in 90% of protein plaques in the brains of deceased patients with Alzheimer’s disease.

However, the scientific world was in no hurry to confirm that the herpes virus can somehow reduce the cognitive functions of patients.

Researchers from Uppsala University and Umeå University in Sweden followed younger patients over a longer period.

Of all 1,002 adult participants they followed for 15 years, 82% carried antibodies to HSV-1. These patients were twice as likely to develop dementia during the study as those who did not carry herpes virus antibodies.

“The peculiarity of this study is that the participants are approximately the same age. This makes the results more reliable because age differences, which are otherwise associated with the development of dementia, cannot influence them.” – explained Erika Westin, an epidemiologist from Uppsala University in Sweden.

Interestingly, the results of this study contradict previous ones. Scientists previously suggested that age and a genetic variant called APOE-4 are predictors of Alzheimer’s disease.

They hypothesized that the APOE genetic variant might enhance the likely effects of HSV-1 on the brain’s immune response.

But participants from Sweden who were carriers of the APOE-4 genetic risk factor were not more likely to have HSV-1 antibody-related cognitive decline.