Dr David Ward from the Centre for Health Services Research tracked the data of nearly 30,000 participants of 4 longitudinal studies in the United Kingdom and the United States, enabling researchers to detect changes in people’s health and function 20 years before they were diagnosed with dementia.

“The accumulation of age-related conditions is indicative of increasing frailty, which we found accelerates up to 9 years prior to a dementia diagnosis,” Dr Ward said.

“Our findings show with every 4-5 additional health problems there is on average a 40% higher risk of developing dementia, while for people who are fitter the risk is lower.

“This suggests frailty is not merely a consequence of undetected dementia but contributes to its onset.”

Frailty is a health state related to ageing where multiple organ systems lose their resilience, making individuals more likely to experience adverse health outcomes like falls, disability and hospitalisation.

“People age at different rates and the number of health problems that accumulate is captured by their degree of frailty,” Dr Ward said.

“By understanding the connection between ageing, frailty and dementia we can use targeted intervention strategies to reduce risk and improve quality of life.”

“This finding supports integrating frailty screening into routine check-ups and could be used to inform health programs which promote lifestyle interventions such as exercise and nutrition.”

According to the World Health Organization more than 55 million people have dementia worldwide, with 10 million new cases every year.

Study co-author, Professor David Llewellyn from the University of Exeter Medical School, said the research was one of the most comprehensive examinations of the link between frailty and dementia.

“This study is crucial because it identifies frailty as a significant predictor of dementia risk, offering a potential pathway for early intervention to improve health outcomes,” Professor Llewellyn said.

“The success of this research hinged on international collaboration, allowing us to investigate different populations and enhance the validity of our findings, which are likely to shape future clinical trials and prevention strategies.”

The study was a collaborative effort between researchers from The University of Queensland, Princess Alexandra Hospital, QIMR Berghofer Medical Research Institute, The University of Edinburgh, Alzheimer Scotland Dementia Research Centre, University of Oxford, University of Cambridge, University of Exeter, Alan Turing Institute, Nova Scotia Health, University of Colorado Boulder, Sapienza University of Rome, Karolinska Institutet, Stockholm University, Italian National Institute of Health, Dalhousie University, and the Medical University of Graz.

The research was supported by the Deep Dementia Phenotyping (DEMON) Network, and the Australian Frailty Network (AFN).

The research paper has been published in JAMA Neurology.