Making the case for dementia prevention
Dr. Barry Greenberg, Director of Strategy at the Toronto Dementia Research Alliance
An ounce of prevention is worth a pound of cure is an old truism with special relevance for Alzheimer's disease, according to the director of strategy at the Toronto Dementia Research Alliance.
"This will be distressing to some people, I know. But I don’t think that a cure is a reasonable expectation," says Barry Greenberg. "I think a more achievable goal is prevention. Once someone has dementia there is already an advanced stage of brain degeneration."
At that point, all doctors can do is manage symptoms, points out Greenberg, who is also director of neuroscience drug discovery and development with Toronto's University Health Network.
It takes an estimated 10 to 20 years for dementia to become obvious because the brain's redundant networks compensate for dying neurons. But if we can identify people in this pre-symptomatic phase, he says, we may be able to treat them with drugs and recommend lifestyle changes that delay or even stop the disease's progression.
"The irony if that’s true is that there could already be drugs that have failed in the clinic that could have been preventative if they were administered in these pre-symptomatic stages. But we haven’t been able to identify those individuals," he says.
This is why Greenberg is enthusiastic about research into pre-symptomatic markers of risk. That includes genetic mutations, biomarkers in cerebrospinal fluid and brain scans that reveal the sticky buildup thought to play a role in the development of Alzheimer's disease. It also includes other biomarkers that, if validated, would provide more accessible, inexpensive and non-invasive measures of risk.
Researchers – including those at several research centres in Canada – are testing an experimental drug to see if it can stave off cognitive decline in participants who have yet to show symptoms.
"The ultimate goal is to prevent it before it ever becomes a clinical manifestation," says Greenberg. "And that’s something which I think is far more reasonable in the foreseeable future than curing the disease once it’s established."