Scientists Find a New Compelling Theory Behind Alzheimer’s


Researchers have tried and failed to identify the underlying cause behind Alzheimer’s disease or find an effective treatment for it, but new evidence from a study suggests that the neurological condition could be caused by the interaction of a common type of virus with the brain cells.

Could Virus Cause Alzheimer’s?

The herpes virus, which often causes rashes and cold sores in young children, is also found in the brains of Alzheimer’s patients, according to a new study published in the journal Neuron.

The theory of herpes virus playing a role in the onset of Alzheimer’s has been a controversial one that has been dismissed by researchers for being too dissimilar from the mainstream theory in the past

But it seems like the controversial idea may have some truth to it. An Alzheimer’s researcher who had previously been one of the biggest skeptics of the herpes theory had a sudden change of heart recently after he published a compelling study backed by strong evidence that the onset of Alzheimer’s may have something to do with the presence of viruses inside the brain.

There are two particular strains of herpes that could trigger the neurological condition in old age. These two types of viruses infect most of the children at a young age but lie dormant inside the brain for years during adulthood. As a person grows older, the virus becomes more active, interacting with brain cells that are linked with Alzheimer’s. This has lead scientists to believe that viruses play a key role in how the disease starts and progresses in old age.

Compelling Evidence

In the paper published in Neuron journal, researchers state clearly that they had no clear evidence showing that the virus directly causes Alzheimer’s, but, given the abundance of viral strains in Alzheimer’s patients, it seems like a plausible explanation that could be studied further.

Another study that will appear in the journals soon also suggests that herpes virus triggers an immune response in old age that leads to the accumulation of a protein called amyloid inside the brain and causes Alzheimer’s

Joel Dudley, the senior author of the research paper said that it is highly likely that these viruses play an important role in triggering an immune response that leads to Alzheimer’s. If the speculations made by Dudley and his research team have any truth in them, the new study could be groundbreaking in the treatment of Alzheimer’s and change the way the disease has been studied until now.

The director of Knight Alzheimer’s Disease Research Center, Dr. John Morris, who wasn’t involved in the study, said that it provides the most compelling evidence to date for the role of viral particles in Alzheimer’s. The researchers extracted almost a thousand human brains from brain banks around the country to study their genetic and molecular structure.

Some of the brains belonged to people who had Alzheimer’s whereas the rest belonged to those with normal neural functions. Dudley discovered that the herpes viruses were more abundant in people with the neurological condition. Morris says that Alzheimer’s isn’t an easy disease to decode, and there is a possibility that a number of different factors play a role in its onset, herpes virus could be just one of them.

More Studies to Come

But not all scientists are taking the herpes theory well. Many are raising the age-old ‘chicken or egg’ question: does herpes virus really trigger Alzheimer’s or is it a consequence of the disease itself? Dr. Lennart Mucke from Gladstone Institute of Neurological Disease says that it could also be possible that the virus is simply an innocent bystander that doesn’t play any part in the neurological condition.

Mucke says that the study is quite remarkable and well-written but to speculate that a viral infection can trigger the onset of Alzheimer’s without providing any compelling cause-effect evidence is simply wrong. However, the recent research is just a prelude to another highly-anticipated study by two Harvard and Massachusetts General Hospital neuroscientists, Robert Moir and Rudolph Tanzi, which will be featured in the Neuron magazine in the near future.

Tanzi and Moir test the virus theory on the three-dimensional brain cells of mice to show that herpes can also trigger the growth of same amyloid proteins that cause Alzheimer’s. Tanzi describes the process as seeding of the amyloids, which in turn trap herpes viruses into plaques.