News
27 October, 2025
Why time is as critical as diet for brain health
TIME or the lack of it could be a missing link in dementia prevention, according to new research from UNSW Sydney’s Centre for Healthy Brain Ageing (CHeBA).
The research, published in The Lancet Healthy Longevity, identifies time as an under-recognised social determinant of brain health, potentially as important as education and income.
The authors argue that “temporal inequity” – the unequal distribution of time across different groups in society – may significantly undermine people’s ability to reduce their risk of dementia.
Lead author and social determinants of health expert Associate Professor Susanne Röhr said that, while lifestyle factors such as sleep, physical activity, nutrition and social engagement are well known to support brain health, they all require one critical resource: time.
“Up to 45 per cent of dementia cases worldwide could be prevented if modifiable risk factors were eliminated,” she said.
“However, many people simply don’t have the discretionary time to exercise, rest properly, eat healthily or stay socially connected.
“This lack of time – what we call ‘time poverty’ – is a hidden barrier to dementia risk reduction.”
The research highlighted how structural conditions, including long working hours, caregiving responsibilities, digital overload, and socioeconomic disadvantage, create ‘time poverty’ that disproportionately affects already vulnerable groups. This, in turn, compounds existing health inequities and limits opportunities for brain-healthy behaviours.
CHeBA Co-Director and co-author Professor Perminder Sachdev said that recognising time as a social determinant of health requires a fundamental shift in how dementia prevention is approached.
“Unless people are given the temporal resources to act on these recommendations, we risk leaving behind those who need it most,” Prof Sachdev said.
“Just as governments act on income inequality, we need to act on temporal inequity.”
The researchers call for policy and workplace reforms to support measures that protect and redistribute time so that everyone can access the opportunity for brain health. Examples include flexible working arrangements, rights to disconnect, affordable childcare, investment in public transport, and urban planning that reduces commuting times.
Co-author Associate Professor Simone Reppermund said future research must also capture how much time is realistically needed for brain care.
“Our evidence suggests that at least 10 hours per day are required just for essential brain health activities such as sleep, meals, physical activity, and social interaction,” Assoc. Prof Reppermund said.
