Study explores biggest risk factor for future dementia cases

Risks posed to heart health may increase future dementia cases, more than smoking, finds a new study on Thursday.

A combination of genetic and environmental factors, including high blood pressure, obesity, diabetes, education, and smoking are major risk factors for dementia.

Researchers from the University College London (UCL) explored how the prevalence of these risk factors changed over time.

The team analysed 27 papers, involving people with dementia globally with data collected between 1947 and 2015, and the latest paper published in 2020.

The results, published in The Lancet Public Health, showed that having less education and smoking had become less common over time and was associated with a decline in rates of dementia.

Rates of obesity and diabetes have increased over time, as has their contribution to dementia risk.

Hypertension emerged as the greatest dementia risk factor in most studies.

"Cardiovascular risk factors may have contributed more to dementia risk over time, so these deserve more targeted action for future dementia prevention efforts," said lead author Naaheed Mukadam from UCL Psychiatry.

Mukadam noted that education levels "have increased over time in many higher-income countries, meaning that this has become a less important dementia risk factor".

Levels of "smoking have also declined in Europe and the US as it has become less socially acceptable and more expensive," the researchers said.