New Scientific Hypothesis Brings Hope of Killing Alzheimer’s
More than five million Americans suffer from Alzheimer’s, a devastating neurological disease that robs patients of their memory and cognitive functioning. Finding a prevention tool has been on the wish list of scientists and treatment providers for decades.
Brain-Infecting Microbes: Old Theory Gets a New Lease of Life
A soon to be published editorial in the Journal of Alzheimer’s Disease will re-open an old conversation as to the cause of Alzheimer’s. According to the editorial, signed by 31 scientists from around the world, the cause of the disease may be microbial infections in the brain, such as Herpes simplex virus 1 (HSV-1), Borrelia burgdorferi, which causes Lyme disease, or Chlamydophila pneumoniae, which causes pneumonia. The experts’ theory is that when the APOE є4 gene variant, which is known to be an Alzheimer’s disease risk factor, is present — a microbial infection can cause debilitating damage to the brain. This theory, dismissed once before, is getting a new look, and if researchers are able to prove it, which will not be easy, then perhaps in the future there will be a way to prevent Alzheimer’s disease.
Microbial Infections Vs. Amyloid Proteins and Tau Tangles
To date, researchers have been focusing on amyloid proteins and tau tangles, which have been proven to be causative agents in the brain cell death experienced by Alzheimer’s patients. While not dismissing the role of these factors, the aforementioned theory that has resurfaced, labeled ‘the pathogen hypothesis’, says that microbial infections are causing the tau tangles and buildup of amyloid proteins, resulting in the ensuing cell death. According to Dr. Brian Balin, Director of the Center for Chronic Disorders of Aging at Philadelphia College of Osteopathic Medicine and co-author of the editorial in the Journal of Alzheimer’s Disease, amyloid proteins play a part in the disease, but only in response to the initial inflammation caused by the microbial infection that is attacking the brain.
Earlier Examinations of the Pathogen Theory Were Not Conclusive
The pathogen theory is not new. In 1979, a study was published in The Lancet, which reported that scientists at the University of Manchester examined patients carrying APOE є4 whose brains were infected with HSV-1. They found that the prevalence of Alzheimer’s was 12 times higher than when only the gene was present or when there was an infection. A 2010 study at Harvard University, headed by Dr. Rudolph Tanzi, Director of Massachusetts Hospital’s Genetics and Aging Research Center, found that amyloid protein seems to accumulate in response to infection. In research conducted since 2010, Dr. Tanzi has found that amyloid protein increases as a defense mechanism to protect the brain from the infection. One of the points of opposition, though, is that HSV-1 can also be found in the brains of healthy older people.
There Are Major Ramifications If the Theory Can Be Proven
If conclusive evidence can be found that microbial infections are a causative agent in the onset of Alzheimer’s disease, it would dramatically alter the way we approach the disease. Instead of dealing with the consequences, patients could be given a vaccine against the infections.
How to Prove the Theory?
The major stumbling block to proving the theory is that it is not possible to determine if infections such as HSV-1 are present in the brain as long as the patient is still living. Only upon death and autopsy can the brain be examined for these microbial infections. It will require many more years of clinical trials to determine if the pathogen theory is valid. Nevertheless, researchers such as Dr. Balin and others believe it is more than worth it to continue with the research. They hope the upcoming editorial will give credence to their approach and also free up much needed funding.