Healthy brain maintenance protects cognitive skills from early Alzheimer's effects

A healthy brain may help protect thinking and memory skills from the early effects of Alzheimer's disease, a new study has found.

Dementia is currently the leading cause of death in Australia and Alzheimer's disease is its most common form - accounting for more than 70 % of cases.

Alzheimer's is a progressive brain disease in which cognitive abilities gradually decline, leading to impaired memory and thinking skills.

However, some people maintain high levels of cognitive function even though their brains show early signs of the disease. Specifically, some older adults have Alzheimer's‑related brain pathology, but no noticeable cognitive problems.

The study, Cognitive and Brain Reserve as Modifiers of Early Alzheimer Disease–Related Cognitive Vulnerability, was a collaboration between Murdoch University and AdventHealth, and investigated why some people remain cognitively healthy despite early Alzheimer's‑related brain changes.

"Our study looked at why some brains were more resilient than others, and whether factors such as peoples' education, socioeconomic status and health of their brain made a difference," said lead author Dr Kelsey Sewell, from Murdoch University's School of Allied Health.

"Understanding these protective factors could help us develop earlier and more targeted strategies to minimise the effects of the disease on memory and thinking skills," she said.

The research team analysed data from more than 600 older adults in the United States aged 65 to 80, who were living independently and had no signs of dementia or memory impairment.

They used blood tests and MRI scans to assess early Alzheimer's‑related changes and overall brain health, examined life and social factors such as years of education, income, savings and financial security, and conducted cognitive tests measuring memory, attention, processing speed, working memory and executive function.

Our main finding was that maintaining good overall brain health may help reduce the impact of Alzheimer's‑related changes on cognitive function."

Dr. Kelsey Sewell, School of Allied Health, Murdoch University

"We also observed early evidence that people with a higher socioeconomic status may be less affected by Alzheimer's-related changes when it comes to memory, although more research is needed to confirm this relationship."

Dr Sewell said the main takeaway for the public was to do everything you can to maintain a healthy brain.

"Things like exercise, maintaining a healthy diet, sleeping well, and finding new cognitive challenges can help to maintain a healthy brain. It is never too late, or too early to start," she said .

"These results underscore the need for coordinated action across research, policy, and industry to design environments that support healthier choices and promote brain health at a population level."

The data collection for this study was led by researchers at AdventHealth in Orlando, Florida.