Experts have identified twelve ways people can reduce their risk of dementia, potentially cutting the number of cases by 40 percent.

In the prestigious medical journal The Lancet experts published their findings after reviewing all the research and data from around the world.

They identified three new risk factors that are associated with dementia.

These include excessive alcohol use, head injuries in mid-life and exposure to air pollution.

The remaining risk factors are associated with 34 percent of dementia cases.

These include lower childhood education, high blood pressure, hearing loss, smoking, obesity, depression, physical inactivity, diabetes and social isolation.

"I think it's an incredibly important insight into what we can do to reduce our risk of dementia by about 40 percent, now that's massive," Associate Professor Michael Woodward, Honorary Medical Advisor for Dementia Australia and Director of Austin Hospital's Memory Clinic said.

"We can do something right now. We don't have to wait until we turn 60 or 70 or 80 to try and prevent dementia," he said.

Nearly half a million Australians are living with dementia and it's the second leading cause of death.

The new report points to specific measures over the course of someone's life to reduce risk.

"These actions require both public health programs and individually tailored interventions," said the Lancet authors.

The actions include encouraging the use of hearing aids and limiting alcohol use, as drinking more than 21 units weekly increase the risk of dementia.

The focus on prevention is even more important as major drug trials in the past have led to disappointment.

Though, a new therapy for Alzheimer's disease is within reach after pharmaceutical giant Biogen applied to U-S health regulators earlier this month to have the drug approved.

The monthly infusion, called aducanumab, was trialled in Australia and around the world. It uses antibodies to clear plaques in the brain.

"If that review comes through as a positive finding, and that will be known by as early as September we will have the first disease modifying drug for Alzheimer's disease, ever." said Dr Woodward.

People who wish to find out how they can improve their brain health or reduce their risk can contact Dementia Australia at or 1800 100 500.

Source: 9News