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Sign on your lips that could mean you're '80% more likely to get dementia'A study has found that a certain virus that can manifest on the lips could indicate a heightened risk of developing

Alzheimer's disease.CommentsNewsFiona Callingham Lifestyle writer12:14, 03 Jun 2025A new study has identified a link between cold sores and risk of Alzheimer's disease(Image: Getty) A

symptom appearing on the lips could potentially signal an increased risk of developing dementia, according to recent research. This viral symptom has been linked with an 80 per cent

increased risk of Alzheimer's disease.

The study, published in the British Medical Journal, suggests that the herpes simplex virus type 1 (HSV-1), a common virus responsible for herpes and cold sores, may contribute to the onset

of Alzheimer's. While previous studies have hinted at a link between HSV-1 and Alzheimer's, this research aimed to delve deeper into this association.

‌ As part of the study, researchers analysed the medical records of over 300,000 individuals aged 50 and above. As reported by SurreyLive, participants were split into two equal groups,

distinguished by those diagnosed with Alzheimer's disease and those without such a diagnosis.

‌ Alzheimer's Research UK detailed how the study found that 1,507 (0.44 per cent) of participants diagnosed with Alzheimer's disease had a history of HSV-1 infection, compared with 823 (0.22

per cent) without an Alzheimer's diagnosis. The conclusion drawn was that individuals with an HSV-1 infection had an 80 per cent increased risk of Alzheimer's.

Cold sores are a common type of infection by the herpes simplex virus that affects primarily the lip(Image: Getty) This remained true even when other factors, such as carrying two copies of

the APOE4 gene, a known risk factor for Alzheimer's, were taken into account. Furthermore, individuals who had been prescribed medication to treat the virus were found to be 17 per cent less

likely to develop Alzheimer's compared to those not on any medication.

Article continues belowLimits of the study Nevertheless, it's essential to consider some constraints of this study. Dr Sheona Scales, director of Research at Alzheimer's Research UK,

highlighted: "Despite the large sample size, this research is based on information gathered from using health records and administrative claims data, which often are based on people

self-reporting their conditions.

"Most people infected with HSV-1 don't have any symptoms so some infections might not have been recorded. Infections predating the information recorded are also not available. Although cases

were matched with controls, diagnosing Alzheimer's disease, especially in the early stages, remains a challenge."

Around 80 per cent of dementia cases worldwide are caused by Alzheimer's disease(Image: Getty)‌ While HSV-1 is common, contracting the virus does not guarantee that an individual will

develop Alzheimer's disease. The precise relationship between HSV-1 and a heightened risk of Alzheimer's is still under investigation, with current hypotheses suggesting that infections may

trigger brain inflammation, potentially leading to damage.

Dr Scales further stated: "We know there are 14 lifestyle and environmental risk factors for dementia, and there's not enough evidence to include infections in this list.

Article continues below "This study doesn't tell us if infections are causing the risk, it only shows an association. Further research is needed to understand what the underlying biology

around this is."

Alzheimer's disease is the most prevalent form of dementia worldwide, accounting for an estimated 80 per cent of all dementia cases.