Scientists have found a link between herpes and dementia risk.
- Anyone who has received a herpes diagnosis may be twice as likely to
develop dementia than people who have not, according to a new study from
Uppsala University in Sweden.
- HSV-1,
the type of the virus that causes cold sores or oral herpes, is most associated with the risk of dementia.
- Nearly 80% of the adult
population in Sweden and 57% to 80% of adults in the United States carries
that type.
Anyone who has received a herpes diagnosis
may be twice as likely to develop dementia than
people who have not, according to a new study from Uppsala University in
Sweden.
The study, which was published in
the Journal of Alzheimer’s Disease, followed 1,000
70-year-old subjects for 15 years and confirmed previous research about the
associations with the herpes virus and dementia.
Herpes results from infection with
the herpes simplex virus (HSV), of which there are two types. Herpes simplex
virus type 1 (HSV-1) causes oral herpes,
affecting the mouth and surrounding skin but also potentially the genital
region. Herpes simplex virus type 2 (HSV-2)
typically causes genital
herpes and is usually sexually transmitted. Nearly 572,000
people have HSV-2 infectionsTrusted Source each
year, according to the Centers for Disease Control and Prevention (CDC).
Dementia is a wide term for cognitive
decline disorders like Alzheimer’s disease and vascular
dementia. It is associated with aging but is not a usual part of
getting older.
Erika Vestin,
a lead author of the study and a Ph.D. student at Uppsala University,
told Medical News Today that the research confirms prior
knowledge about the connections between dementia and herpes, but causality is
still not concrete.
“We still do not have answers
regarding causal mechanisms of this association, whether the virus causes the
disease or if there is an indirect link,” Vestin said.
“Further, the association remains to
be studied in different social and ethnic groups, and potential effects of
herpes drugs on dementia risk need to be investigated in pharmaceutical drug
studies,” she added.
How
common is herpes and dementia?
According to the World Health
Organization (WHO)Trusted Source,
more than 55 million people worldwide have dementia and nearly 10 million more
will receive a diagnosis of dementia each year. By 2030, it is estimated that
the number of people with dementia will reach 78 million.
HSV, which remains for a person
throughout their life, is quite common. According to the WHOTrusted Source, around 67% of people
under age 50 globally have an HSV-1 infection, and 13% under age 50 have an
HSV-2 infection., and 13% under age 50 have an HSV-2 infection. Most people
with HSV-2 may not know they have it: Approximately 87.4%Trusted Source of
people between the ages of 14 and 49 with genital herpes do not have a clinical
diagnosis.
Up to 80% of the adult population in
Sweden may have contracted HSV-1 at some point. The statistics are similar in
the United States: 57% to 80% of
adultsTrusted Source here have oral
herpes.
The herpes virus causes sores
or blisters in
or around the mouth or genitals, alongside other symptoms. There is no cure for
herpes, but treatment can help manage symptoms and reduce the
likelihood of outbreaks recurring and transmission to partners.
What
is the link between herpes and dementia?
Vestin said that the oral form of
herpes is most likely the main factor in any connection between HSV and
dementia, but that the virus itself can complicate those connections.
“The main culprit seems to be HSV-1,
which commonly infects the oral region,” Vestin said. “However, HSV-1 and HSV-2
can both infect either the oral or the genital region, which is important to
have in mind when these studies are conducted.”
Dr. Monica
Gandhi, MPH, an infectious diseases specialist with the University
of California, San Francisco, told MNT that the study does
not prove causality.
“There could be important differences
between those with or without herpes simplex virus (HSV) IgG status (past
exposure) and those who developed dementia or not. It is difficult to control
all confounders that have been traditionally associated with dementia (like
diabetes, hypertension,
history of stroke or myocardial
infarction), and the authors state that their entire cohort had
relatively low rates of these conditions,” Dr. Gandhi said.
“The authors did not find an association
between treatment for HSV and dementia, which would be an interesting
observation to see in another study if we wanted to be more convinced of a
causal link,” Dr. Gandhi added.
“A good matched study where a group
is matched on almost all possible confounders for dementia (hypertension,
diabetes, smoking, other risk factors) to another group with the same risk
factors but only one difference (HSV IgG status) could be helpful in providing
further evidence,” she added.
Should
I be worried if I have a herpes diagnosis?
Vestin suggested that getting
diagnosed and treated with widely available drugs for the herpes virus would
benefit anyone who does have it and indicated that previous research backs
this.
“There are indications from large
register studies that herpesvirus drug use may be associated with a decreased
risk of dementia among symptomatic herpes simplex carriers. However, there are
no pharmaceutical trials to confirm this. For now, herpes simplex carriers will
have to rely on the same advice as the rest of the population, involving mainly
lifestyle factors and cardiovascular health,” she said.
Dr. Gandhi said that the rates of
herpes and dementia are different enough — and there are wildly divergent
factors for any individual’s susceptibility — to warrant some caution around
the study’s findings.
“The prevalence of HSV-1 and HSV-2 is
very high in the population (up to 80%) and the rate of dementia is fortunately
much lower. Traditional risk factors
for strokes (which can induce dementia) include diabetes,
hypertension and smoking, so keeping those factors controlled can be helpful
for a person’s individual risk of dementia,” Dr. Gandhi said.
“Given how common herpes virus
infection is [in] young people, I would not let this study concern you too
much,” she added.
No comments:
Post a Comment