Abnormal proteins that accumulate in the brain, amyloid and tau, are both factors that lead to Alzheimer’s and other forms of dementia, according to researchers at Douglas Mental Health University Institute.

The team, led by Dr. Pedro Rosa-Neto, a clinician scientist at Douglas and assistant professor of neurology, neurosurgery and psychiatry at McGill University, reported that the interaction between amyloid and tau proteins can cause brain damage in otherwise cognitively healthy individuals.

Over a two-year study, 120 individuals with an average age of 75, had their amyloid levels measured using a PET scan while tau proteins were measured through cerebrospinal fluid analysis. “Those individuals with the highest levels of toxic proteins detected by PET amyloid imaging and cerebrospinal fluid, developed abnormalities typical of Alzheimer’s disease,” Dr. Rosa-Neto, told HCB News.
“We specifically found that both proteins mutually enhance their individual toxic effects and cause a brain dysfunction considered to be a signature of Alzheimer’s disease,” said Dr. Rosa-Neto, in a statement, “This finding challenges previous polarized theories that single protein abnormality was the major driving force of disease progression.”

In a healthy brain, amyloid is broken down and eliminated while in patients with Alzheimer’s, there is a buildup of the protein which would then create plaque and interfere with cell-to-cell communication in the brain. Tau collapses into twisted strands called tangles, and nutrients are no longer able to move through the cells, which would eventually die.

Dr. Tharick A. Pascoal, lead author of the study, said in a statement that until now, therapeutic clinical trials targeted a single pathological process, and the research can create new therapeutic strategies for stabilizing or preventing the disease.

Dr. Rosa-Neto told HCB News, “There is an emerging literature suggesting that physical exercise might improve the washout of brain toxins causative of dementia. Furthermore, exposure to cognitive challenging activities, healthy diet and controlling blood pressure, blood sugar and cholesterol may protect people against dementia.”

He continues on to say that one of the biggest challenges for preventive therapies of dementia is measuring the disease progression in patients without symptoms. But the study demonstrates how using brain scans makes it possible to quantify Alzheimer’s before symptoms begin.

Earlier this year, researchers from Switzerland developed a capsule that can potentially deliver antibodies to the brain that clear accumulation of amyloid.

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