PEOPLE who get cold sores could be at increased risk of developing dementia, a study suggests.
Researchers found those who had the herpes simplex virus (HSV) – the main cause of the ailment – were twice as likely to develop the brain-robbing condition than those who have never been infected.
Getty ImagesCold sores could put you at increased risk of developing dementia, research suggests[/caption]
Scientists at Uppsala University in Sweden studied 1,002 people aged 70 who didn’t have dementia over a 15-year period.
Each underwent testing at 70, 75 and 80, then their medical records were tracked at age 85.
Blood samples were taken to detect antibodies, and cognitive impairment exams were administered.
An experienced geriatrician reviewed the diagnoses and classified cases as established or probable dementia or Alzheimer’s disease (not including mild cognitive impairment), according to standard clinical procedures.
When unable to differentiate between Alzheimer’s and other dementia disorders, cases were registered as ‘all-cause dementia‘.
In the cohort, some 71 (seven per cent) of participants developed all-cause dementia, and 36 (four per cent) developed Alzheimer’s.
More people tested positive for HSV in these groups (89 per cent) than those without dementia (82 per cent).
Analysis revealed that the presence of HSV was associated with a more than doubled risk of dementia.
No significant association was found with Alzheimer’s.
The authors noted that it is likely the presence of HSV, not the level of it, that is indicative of risk.
What is herpes simplex virus?
Herpes simplex virus (HSV) causes both cold sores and genital ulcers in adults. It is highly contagious and very common.
According to the World Health Organization (WHO), an estimated 3.7billion people under 50 have it.
Cold sores, which are small fluid-filled blisters common on the lips, spread through close contact, such as kissing, and may be passed through shared objects like cutlery.
The NHS says: “Cold sores are contagious from the moment you first feel tingling or other signs of a cold sore coming on to when the cold sore has completely healed.
“Cold sores take time to heal and they’re very contagious, especially when the blisters burst.”
In adults, the herpes virus is also spread through oral sex.
HSV remains in the body for the rest of your life, and can cause recurring attacks.
While some people experience the same throbbing symptoms, many live without any.
Source: World Health Organization and NHS
Author Erika Vestin said: “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.
“In this prospective epidemiological study, anti-HSV IgG seroprevalence was associated with a doubled risk of dementia in an older population.”
The team, whose work was published in the Journal of Alzheimer’s Disease, hope that further investigation could reveal that drugs that fight against HSV could lower someone’s risk of dementia and even help produce vaccines to prevent it.
“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,” Vestin said.
Previous studies have looked at the viral link between cognitive decline and HSV.
One, by Oxford’s Institute of Population Ageing, Tufts University in the US and the University of Manchester, found that older people had more abnormal tau proteins in their brains than adults who didn’t have the virus.
Tau proteins are microtubules which transport nutrients from one part of the brain to another.
Abnormal or misshapen tau proteins cannot do their job properly, meaning parts of the brain are starved of vital nutrients.
Having too many misshapen tau proteins is thought to be a driver of Alzheimer’s.
The scientists believe that the more cold sore flare-ups a person has throughout their life, the more abnormal proteins are likely to develop – so their risk of Alzheimer’s could be higher.
The difference between Alzheimer’s and dementia
Dementia is a general umbrella term used to describe the deterioration of a person’s mental ability.
It is a group of symptoms, such as memory loss, confusion, problems with language and understanding, and behaviour changes.
There are many different types of the debilitating condition, and Alzheimer’s is the most common.
It accounts for 60 to 80 per cent of dementia cases, which is why the names may sometimes be used interchangeably.
An estimated 944,000 people in the UK have dementia. This is projected to rise to 1.6million by 2040.
Source: Alzheimer’s Society and NHS