Chilli, the spicy fruit that can send people running for a glass of milk, could hold dementia-preventing powers, researchers at a Queensland university say.

University of Southern Queensland scientists will later this month study the cognitive impacts the molecule capsaicin, found in chillies, has on preventing dementia and other health conditions in people.

Researcher Edward Bliss said dementia has modifiable risk factors — including fat mass "around the belly" — and his previous published studies of the capsaicin molecule in animals found it helped address some of those risks.

He said capsaicin reduced how much rats on a high fat and high sugar diet would eat, which also reduced their weight.

"But that also had a follow-on effect where it reduced inflammation throughout the body, particularly in the heart and blood vessels," he said.

He said the study also showed improved cognition, memory and reduced Alzheimer's plaques that were formed, or unusual clumps of protein found in the tissue between nerve cells.

First step to more research

Dr Bliss said he would now expand that study to humans. Over 12 weeks, about 40 participants in Toowoomba and Ipswich will be given either a capsaicin supplement or a placebo and their cognitive functions will be tested, among other measures.

"This is the first step we're taking here. It's a pilot study or a feasibility study," he said.

"The only thing that has been studied as far as cognition is concerned is a large study from China, where they looked at chilli consumption and the higher the consumption the higher the self-reported cognition was."

Dementia Australia's medical advisor Associate Professor Michael Woodward, who is not involved with the USQ research, said it was the latest in several pieces of research looking at the potential impact of spices.

He said this included research from Sydney and Perth on turmeric in dementia.

"The idea that these products, these natural products, might actually have an effect on brain function is not new," he said.

"So, you might have the protective effect of chilli, of capsaicin, but then you're losing the protective effect of exercise."

How to reduce dementia risk

Associate Professor Woodward said the risk of developing dementia could be reduced by 40 per cent if, from midlife, an individual exercised for about 40 minutes a day, five times a week and ate a healthy diet, such as the Mediterranean diet.

"It is a better diet for the brain and for the heart," he said.

"We also need to keep our brain active, be socially engaged and avoid loneliness."