The herpes virus of the lip (HSV1) may increase the risk of developing Alzheimer’s disease. But when people are treated with specific antiviral therapy, the risk of the disease decreases.
3.7 billion people worldwide are affected by type 1 herpes according to a publication by the World Health Organization. The infection can be caused by two types of virus: HSV1 for cold sores, the famous “cold sore” or HSV2 for genital herpes.
Using data from three Taiwanese epidemiological studies, scientists from the University of Manchester and Edinburgh have found that people infected with this virus have a higher risk of developing Alzheimer’s disease.
A risk multiplied by ten
The study was carried out on 8,362 people, over the age of 50, recently diagnosed with severe cold sores and followed over a period of ten years. The results obtained were compared with those of a control group made up of 25,086 people without obvious herpes. People with severe herpes had a 2.5 times higher risk of getting Alzheimer’s disease, but for those who were treated with antiviral treatment, the incidence of the disease was divided by ten!
The researchers have, moreover, observed the presence of the DNA of the herpes virus in the amyloid plaques, the lesions responsible for Alzheimer’s disease. According to them, the process of reactivation of the herpes virus in the brain could be the cause of the disease. Certain psychological factors can explain that herpes reoccurs such as stress for example, but it can also be linked to an infection or inflammation in another part of the body.
Hope for a cure
“This also highlights the possibility in the future of preventing the disease by carrying out vaccines against infection during childhood”, underlines Professor Itzhaki, one of the authors of the study. For the time being, no treatment can truly cure Alzheimer’s. According to France Alzheimer, in France, 850,000 people are affected across France. If the disease continues to progress at the same rate, there could be more than two million people affected by 2040.
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