Scientists have warned that harboring tumors may increase the risk of Alzheimer’s disease.
A study by the University of Oxford found that the infection could trigger a chain reaction in the brain linked to dementia.
It does this by awakening another, usually harmless, herpes virus that has been dormant in our bodies since childhood.
This leads to a “dramatic” buildup of plaque and inflammation in the brain, two hallmarks of Alzheimer’s.
Chickenpox occurs when the body is first exposed to the varicella zoster virus (VZV), usually during childhood. Shingles is the result of subsequent infections.
To see how VZV affects the brain, the researchers used lab-grown brain cells to create three-dimensional brains.
They found that Alzheimer’s disease did not directly cause signature changes.
But it reactivated the herpes simplex virus (HSV-1), which is known to cause cold sores, prompting rapid accumulation of harmful proteins.
Study author Dana Cairns, from Tufts University in Massachusetts, said: “It’s a one-two punch of two very common and usually harmless viruses.
Tumors increase risk of Alzheimer’s disease, scientists warn, triggering chain reaction in brain (file photo)
“But laboratory studies show that new exposure to VZV can cause problems if HSV-1 wakes up from sleep.”
HSV-1 usually sleep in the body and there is strong evidence that it is linked to dementia.
Air pollution causes dementia for the first time, says UK government
Air pollution is contributing to the rise in dementia for the first time, the UK government has said.
Airborne toxic particles from cars and fuels have long been linked to a rapid rise in disease in the UK and the developed world.
Now, a major independent review has confirmed the link after analyzing dozens of human studies.
The researchers concluded that “air pollution contributes to cognitive decline and dementia in the elderly.”
They believe that the main reason for this is that small toxic particles enter the bloodstream after inhalation into the lungs.
The pollutants then irritate blood vessels and impair circulation in the brain. Over time, this can lead to vascular malformations.
Also, in rare cases, very small air pollution particles can cross the blood-brain barrier and directly damage neurons.
But this does not appear to be an important mechanism for air pollution levels in the UK at the moment, the report said.
Previous research has shown that older adults with higher levels of the virus in their brains are at a higher risk of developing Alzheimer’s disease.
Professor Ruth Yitzhaky of the University of Manchester worked with researchers from Oxford’s Institute of Population Aging and Tufts University on the latest study.
The researchers recreated brain-like environments in 6-millimeter donut-shaped sponges made of silk protein and collagen.
The sponges were filled with stem cells that became neurons and could transmit signals to each other, just like in the brain.
The results showed that neurons in the brain can be infected with VZV, but this alone does not lead to plaque formation and cell death.
The infected neurons were still able to function normally.
However, if the cells also contained HSV-1, there was a dramatic increase in tau and beta-amyloid proteins, which are closely related to dementia.
Neuronal signals also began to slow down.
Professor Itzaki said: ‘This surprising finding suggests that in humans, infections such as VZV can lead to increased inflammation in the brain, which reactivates dormant HSV-1.
“Brain damage from repeated infections over a lifetime eventually leads to the development of AD/dementia.
“These vaccines may play a role in more than just protection against the disease, because they may indirectly provide some protection against Alzheimer’s.”
The study was published in the Journal of Alzheimer’s Disease.
Shingles can be very painful and affects people more as they get older.
About one in five people who get chickenpox will develop chickenpox, and most of them are in their seventies.
Researchers also warn that obesity, smoking, alcohol and head trauma can increase the risk of Alzheimer’s disease by weakening the immune system and activating dormant HSV1 in the brain.
Today, more than 900,000 people in the UK are living with dementia, which is expected to rise to 1.6 million by 2040.
Alzheimer’s disease is the most common form of dementia.
Current estimates suggest that about 5.8 million people in the United States have the disease, most of whom are over 65 years of age.
WHAT IS DEMENTIA? A KILLER DISEASE THAT REQUIRES SUFFERERS TO REMEMBER
Dementia is an umbrella term used to describe a range of progressive neurological diseases (those affecting the brain) that affect memory, thinking and behaviour.
There are many types of dementia, of which Alzheimer’s is the most common.
Some people may have a combination of dementia types.
Regardless of the type of diagnosis, each person experiences their mental disability in their own way.
Dementia is a global problem, but it is more common in wealthy countries where people live to a very old age.
HOW MANY PEOPLE ARE MADE?
More than 900,000 people in the UK today have dementia, according to the Alzheimer’s Society. This is 1.6 million by 2040.
Alzheimer’s disease is the most common form of the disorder, affecting 50 to 75 percent of those diagnosed.
In the United States, the number of people with Alzheimer’s disease reaches 6 million. A similar percentage increase is expected in the coming years.
As a person ages, so does the risk of dementia.
Although diagnosis rates are improving, many people with dementia are still thought to be undiagnosed.
IS THERE A CURE?
There is currently no cure for dementia.
But new drugs can slow its progression, and the earlier it’s detected, the more effective the treatment.
Source: Alzheimer Society