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Junk food diet linked to Alzheimer’s disease

Women who eat a diet filled with unhealthy junk food have higher rates of the hallmark Alzheimer’s protein beta-amyloid in their brains - putting them at greater risk of developing dementia.

A new Australian Catholic University study, published in Science Direct, found women who stuck to diet of junk food had more beta-amyloid in their brain when compared those who ate predominately high-fat, Mediterranean, or low-fat diets.

Lead author and PhD candidate Edward Hill said the findings highlighted the important connection between the food on our plates and dementia, including Alzheimer’s disease, which is the leading cause of death for women in Australia.

“This study shows that changing the way we eat can delay ageing in our brain and reduce the risk of dementia,” he said.

“Prior to clinical Alzheimer’s becoming obvious, the protein called beta-amyloid begins to accumulate in the brain and is a valuable biomarker to calculate someone’s future risk.

“With no drug treatment for Alzheimer’s disease currently available, research is shifting towards modifiable lifestyle risk factors such as diet.”

Dementia is a broad term for diseases – including Alzheimer’s – that gradually reduce brain function. These diseases cause thinking, behaviour, and the ability to carry out everyday tasks to become significantly impaired over time, affecting quality of life.

It is estimated that with increasing age and the expanding baby boomer population, there will be up to 130 million people with Alzheimer’s disease worldwide by 2050.

Mr Hill said this is the first study to investigate dietary patterns and beta-amyloid accumulation in women.

“We know that sex, family history and genetics are important risk factors for Alzheimer’s disease, but we wanted to look at whether dietary patterns are related to how much of the hallmark Alzheimer’s protein we have in our brain,” he said.

Mr Hill and a team of researchers at ACU and the University of Melbourne, who are part of the 20-year Women’s Healthy Ageing Project, looked at the dietary patterns of 115 women and found four distinct dietary patterns – high-fat, Mediterranean, junk food and low-fat.

Understanding how to slow the processes that drive ageing in the brain is significant given that prevention is currently the only cure for dementia.

"Even if there is a genetic risk, we can change the course of our genes to a certain extent. It’s not too late to adopt a healthier lifestyle to prevent or delay the disease,” he said.

“While our findings relate to women, we know healthy lifestyles are important for men to maintain their brain health too.”