New predictors of Alzheimer’s disease

Man with Azheimer's disease and nurse. | Newsreel
New research is linking the likelihood of developing Alzheimer's disease with other conditions. | Photo: Suneknly (IStock)

A new study has linked the likelihood of a person developing Alzheimer’s disease with that person’s other medical conditions.

The Australian Imaging, Biomarker and Lifestyle Study, conducted by The Florey, found that while some medical conditions appeared to increase the likelihood of developing Alzheimer’s disease, others appeared to decrease the odds.

Led by Dr Yijun Pan, the study by the largest brain research centre in the Southern Hemisphere, based in Victoria, found anxiety and other neurological disorders increased the likelihood of Alzheimer’s disease.

“People with anxiety and neurological disorders are 1.5 and 2.5 times more likely to have Alzheimer’s disease. For people with anxiety, males have higher odds than females of developing Alzheimer’s disease,” Dr Pan said.

The study, published in Alzheimer’s and Dementia: Diagnosis, Assessment and Disease Monitoring, found several medical conditions were linked to lower odds of Alzheimer’s disease, such as arthritis, cancer, gastric complaints, and high cholesterol.

“The reasons for the connections were complex,” Dr Pan said.

He said the protein p53, which had been shown to regulate amyloid-beta mediated neuron death seen in Alzheimer’s disease, was also known to lose its function with cancer, providing a possible explanation for the connection between the two conditions.

“We need further research to understand whether these diseases interfere with the evolution of Alzheimer’s or whether there might be other reasons,” he said.

The study reported no significant association observed between depression, falls or stroke and Alzheimer’s disease.

Dr Pan said the research provided a useful insight into the complex interconnections between the many conditions at play for most people with Alzheimer’s disease.

The release of the report coincided with the news from the University of South Australia that work is underway to explore how harmful gut bacteria accesses the brain and leads to dementia.

Nano bio-scientist Dr Ibrahim Javed said tiny metabolites released by bad bacteria in the gut could travel to the brain, causing inflammation and triggering Alzheimer’s disease.

“In younger people this is less likely because the blood-brain barrier is much stronger, but this weakens as people age, allowing harmful substances to damage neurons. When the microbiome in the gut ages, it also loses the ability to fight disease,” Dr Javed said.

He said by identifying how metabolites released by bad bacteria damage neurons and developing new drug therapies to block them, it should be possible to slow down or halt the progression of Alzheimer’s.