A 1997 study is renewing concerns about the link between cold sores and Alzheimer’s disease. Researchers found herpes simplex virus 1 (HSV-1), typically contracted in childhood, dormant in the brains of some elderly individuals. They suggested that people with both HSV-1 and the ApoE-e4 gene could have a higher risk of developing Alzheimer’s.
Dr. Ruth Itzhaki, a study co-author, recently highlighted new research that supports this connection, prompting experts to re-examine its significance.
What Is HSV-1?
HSV-1 is a common virus that nearly everyone contracts by adulthood, often causing cold sores. It remains dormant in the nervous system and can be reactivated by stress or a weakened immune system. Though there is no vaccine for HSV-1, antiviral drugs can treat cold sore symptoms.
How Could HSV-1 Contribute to Alzheimer’s?
Researchers believe that reactivated HSV-1 may trigger brain inflammation, a condition known as herpes encephalitis. This could contribute to Alzheimer’s in people with genetic risk factors, like the ApoE-e4 gene, which makes the blood-brain barrier more vulnerable to viral entry.
“Chronic inflammation in the brain is a key factor in Alzheimer’s development,” says Dr. David Hunter, a neurologist.
What Experts Say
Studies have found HSV-1 DNA in the brains of Alzheimer’s patients, and lab studies suggest HSV-1 may trigger amyloid-beta and tau buildup, which are linked to Alzheimer’s. However, experts caution that the virus’s long-term effects are more concerning in people who contract it early in life.
Most cold sores aren’t a concern, but people with frequent outbreaks, weakened immunity, or the ApoE-e4 gene may want to discuss the issue with a healthcare provider.
What’s Next?
More research is needed to understand how antiviral treatments could affect Alzheimer’s risk and how to detect HSV-1 activity in the brain. Early intervention could potentially help prevent Alzheimer’s.
Reducing Dementia Risk
Experts recommend lifestyle changes, such as getting vaccinated, exercising, and avoiding smoking, to reduce dementia risk. A healthy diet and mental stimulation are also beneficial for brain health.
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