The risk of developing dementia is becoming increasingly associated with poor cardiovascular health, according to a study published in the journal The Lancet Public Health. A team of researchers from UCL in London say that aspects that were important in the past, such as smoking and education, are becoming less relevant now.
There are currently over 900,000 people living with dementia in the UK, and more than half of the population knows a friend or relative who has been diagnosed with some form of the disease. It is one of the biggest killers and has been the leading cause of death in women in the UK since 2011.
Much of the research in this area focuses on understanding and eliminating certain risk factors. In theory, eliminating these could prevent about 40% of dementia cases. In this study, the team analysed 27 papers with data collected from patients with dementia between 1947 and 2020. They considered all the information from each paper about dementia regarding risk factors and calculated what proportion of dementia cases were attributable to each one during that period.
Dementia develops because of a combination of genetic and environmental factors, such as hypertension, obesity, education, and smoking. For a long time, patients who were heavily smoking and had low qualifications were at a high risk of developing the condition, but these have become less important over the years. In contrast, the risk of dementia caused by obesity and diabetes has increased.
“Cardiovascular risk factors may have contributed more to dementia risk over time, so these deserve more targeted action for future dementia prevention efforts,” said Dr Naaheed Mukadam from UCL Psychiatry. “Our results show that levels of education have increased over time in many higher income countries, meaning that this has become a less important dementia risk factor. Meanwhile, smoking levels have also declined in Europe and the USA as it has become less socially acceptable and more expensive. These patterns suggest that population-level interventions could significantly impact the occurrence of dementia risk factors, and governments should consider implementing schemes such as worldwide policies of education and restrictions on smoking.”
Mukadam N, Wolters FJ, Walsh S, Wallace L, Brayne C, Matthews FE, Sacuiu S, Skoog I, Seshadri S, Beiser A, Ghosh S, Livingston G. Changes in prevalence and incidence of dementia and risk factors for dementia: an analysis from cohort studies. Lancet Public Health. 2024 Jul;9(7):e443-e460.