EVERY six minutes someone in Australia is diagnosed with dementia, the third leading cause of death nationally.

So Tweed mayor Barry Longland has signed up for the Heart Your Brain Challenge and will train in brain health habits for three weeks as part of Dementia Awareness Week.

"I'm excited about taking up the Brain Challenge and will dust off my guitar in an attempt to learn a new song on my guitar each week, practising every day during the challenge," Cr Longland said.

"We've only got one brain so it's vitally important to do whatever we can to reduce the risk of developing dementia and looking after our brain health."

Cr Longland will start his challenge at the Tweed Memory Walk on September 29.

The Memory Walk, at Jack Evans Boat Harbour, is the major event of Dementia Awareness Week in Tweed Shire, which runs from September 16-22.

More than 320,000 people have dementia in Australia. This number is projected to reach more than half a million by 2030.

Dementia is the term used to describe the symptoms of a large group of illnesses which cause a progressive decline in a person's functioning.

It is a broad term used to describe a loss of memory, intellect, rationality, social skills and physical functioning. It is more common for those aged over 65, but can affect younger people too.

Head to yourbrainmatters.org.au to find out more about the challenge and how to lead a 'brain healthy' lifestyle.

Alzheimer's Australia provides advocacy, support services, education and information for dementia sufferers and their families.