Australian researchers have uncovered a link between smoking and an increased risk of dementia.

Dr Kaarin Anstey from the Centre for Mental Health Research at the Australian National University reviewed the link between smoking and dementia in more than 13,000 people.

She found current smokers have an increased risk of dementia and cognitive decline, ranging from 40 to 80 per cent compared to people who never smoked.

"This paper really shows for the first time very clearly that current smoking is a risk factor for dementia and it really puts a lot of weight behind a public health message that smoking is not only a risk for things like lung cancer, it is also a risk factor for dementia," she said.