Doctors may be able to identify people who are at risk of developing Alzheimer's disease years before symptoms surface, recent research has found.

A study published Wednesday afternoon in Neurology suggests advanced brain imaging technology has been able to spot certain chemical changes in the brains of people who might be in danger of developing the degenerative disease.

"We're pretty certain now that the changes in the brain begin decades before the actual symptoms appear, 20, 30, maybe even 40 years before you get symptoms," Dr. Jack Diamond from the Alzheimer's Society of Canada told CTV News.

Researchers zeroed in on those specific chemical changes after studying the brains of 311 seniors, between the ages of 70 and 80.

The participants underwent a brain scanning procedure called "proton MR spectroscopy" and were then tested on memory, language and other cognitive abilities.

When the test results came back, researchers noticed study participants who had high levels of amyloid-beta deposits and choline/creatine scored lower on the tests than those with lower levels of the chemicals.

"We think these chemical changes are giving us important information about possible early Alzheimer-related changes in the brain,"study author and Minnesota-based doctor Kejal Kantarci from the Mayo Clinic said.

Kantarci, however, stressed that more research is needed "to determine which of these individuals will actually develop the disease" and to study the relationship between the chemicals in the brain.

Currently, the brain imaging technology used in the study cannot be used to diagnose Alzheimer's disease.

But Diamond said the study could be used to further Alzheimer's research and helping those most at risk.

"We haven't got them yet, but they're going to come," Diamond said about Alzheimer's drugs. "The time to apply those treatments is as early as possible."

Half a million Canadians have Alzheimer's disease or a related form of dementia, according to numbers from the Alzheimer's Society Canada. Approximately 71,000 of those people are under age 65.

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip