Around 50% of dementia cases worldwide may be preventable

PHILADELPHIA – Nearly half of dementia cases worldwide could theoretically be prevented or delayed by eliminating 14 modifiable risk factors over an individual's lifetime, according to a report from the Lancet Commission on Dementia Prevention, Intervention and Care.

The report added two new modifiable risk factors for dementia: high cholesterol and poor vision. 12 Risk Factors Identified in 2020 Lancet The committee's report said it is linked to about 40 percent of all dementia cases.

original Lancet Committee Report, Published In 2017, we identified nine modifiable risk factors estimated to account for one-third of dementia cases.

“Our new report makes clear that there is much more that can and should be done to reduce the risk of dementia. It is never too early or too late to act – there are opportunities to make an impact at every stage of life,” lead author Jill Livingstone, MD, of University College London, UK, said in a statement.

The 57-page report Publish online July 31 of The Lancet Neurology In line with the announcement at Alzheimer's Association International Conference 2024.

'Compelling' new evidence

The 12 risk factors listed in the 2020 report include low educational attainment; Hearing loss, High blood pressure,smoking, obesity, depressionlack of exercise, diabetes, excessive alcohol consumption, Traumatic brain injury (TBI), air pollution, and social isolation.

The authors of the current report say there is “new and compelling evidence” that untreated vision loss and elevated low-density lipoprotein (LDL) cholesterol are also risk factors for dementia.

These two additional risk factors are associated with 9% of dementia cases, of which 7% are thought to be due to high blood pressure. LDL cholesterol According to the authors, vision loss begins from about age 40, and 2% of cases are due to untreated vision loss later in life.

Of the 14 risk factors, those associated with the greatest proportion of dementia in the world's population are: Hearing impairment The report estimates that high LDL cholesterol levels (7% each), lower educational attainment in childhood, and social isolation in later life (5% each) are associated with this risk.

The new report also outlines 13 recommendations for individuals and governments to help prevent dementia, including preventing and treating hearing loss, vision loss and depression, staying cognitively active throughout life, using head protection in contact sports, reducing vascular risk factors (high cholesterol, diabetes, obesity and high blood pressure), improving air quality and providing supportive community environments to increase social contact.

Dr Tara Spires-Jones, President of the British Neuroscience Society, highlighted that while the study does not directly link dementia to any particular factor, it adds to the evidence that a healthy lifestyle that includes education, social activity, exercise, cognitive engagement and avoiding head trauma and factors that are harmful to heart and lung health can make the brain more resilient and prevent dementia.

In an interview Medscape Medical News“Our brains are complex, and events that happen throughout our lives can increase or decrease our risk of developing dementia as we age,” said Heather M. Snyder, PhD, senior vice president of medical and scientific affairs at the Alzheimer's Association. “Protecting brain health as we age requires a comprehensive approach that includes discussions about diet, exercise, heart health, hearing and vision.”

And commenting on the new report, Shaheen Rakan, MD, a Miami, Florida-based neurologist and researcher, said the addition of high cholesterol is particularly noteworthy because it “confirms the complex relationship between vascular health and brain health — a relationship that has long been suspected but can now be more effectively targeted.”

Regarding vision loss, Laquin said, “It's not just a matter of being able to see clearly, but of being able to think clearly. Untreated vision loss can lead to social isolation, reduced physical activity and impaired cognitive function.”

Dementia is not inevitable

“The possibility that we could prevent or delay around half of dementia by addressing these risk factors is truly revolutionary – changing the way we view dementia from being an inevitable part of ageing to seeing it as a disease that can be actively prevented,” Laquin added.

He said it was also important that the report emphasized health equity.

“Dementia risk factors disproportionately affect socio-economically disadvantaged groups and low- and middle-income countries. Addressing these disparities is not just a question of equity in the fight against dementia – equity in prevention is as important as equity in treatment,” commented Laquin.

He said the report offers hope but also presents challenges.

Implementing the recommended preventive measures requires “a concerted effort by individuals, health systems and policymakers.” “Given the potential benefits in terms of both quality of life and economic savings, this effort is not only worthwhile but essential. Preventing dementia is not only a medical imperative, it is also an economic and humanitarian imperative,” Laquin said.

Dr Masood Hussain of the University of Oxford in the UK agreed.

The report's conclusions are “hugely important for all of us, but particularly for health policy makers and governments,” he told the Science Media Centre.

“Simple things like screening for some of the factors identified in this report, if done well with enough resources, could prevent dementia on a national scale. This would be much more cost-effective than developing high-tech treatments that have so far been disappointing in their impact on people with advanced dementia,” Hussain said.

of Lancet The commission is funded by University College London, UK, the Alzheimer's Society, the UK Association for Alzheimer's Research and the Economic and Social Research Council. A full list of author disclosures can be found in the original article. Snyder, Lakhan, Husain and Spires-Jones have no relevant disclosures.