A landmark study has revealed that despite some improvements in individual health behaviours, the overall proportion of dementia cases in Australia linked to modifiable risk factors has remained unchanged.
The research, published in The Lancet Healthy Longevity, examined national health survey data from 2007 to 2022 and found that nearly half of dementia cases in mid-life and over half in late-life could still be attributed to preventable factors.
The study assessed 12 modifiable risk factors including smoking, physical inactivity, poor diet, depression, and low education.
While the prevalence of smoking, high alcohol intake, and low education declined, these gains were offset by increases in obesity, poor diet, and particularly depression.
Depression emerged as the leading modifiable risk factor in 2022, especially affecting women and individuals in lower-income households.
UNSW Ageing Futures Institute researchers including Heidi Welberry, Louisa Jorm, Kim Kiely, Ruth Peters, Hamidul Huque and Kaarin Anstey found that men and people in the lowest 40% of household income consistently had a higher number of risk factors.
In mid-life, men had significantly more risk factors than women, while in late-life, the gap narrowed.
Socioeconomic disparities were also stark, with low-income groups showing a much higher burden of modifiable risk factors across both age groups.