Lifestyle, Policy Changes Could Make Big Dent in Dementia Burden

About 40% of dementia cases may be prevented or delayed by modifying 12 risk factors, researchers reported at the 2020 virtual Alzheimer's Association International Conference (AAIC).

These 12 factors include three new items -- excessive alcohol intake and head injury in mid-life, and exposure to air pollution in later life -- that have been added to the Lancet Commission's list of key modifiable risk factors for dementia, said Gill Livingston, MD, of University College London in England, and co-authors, during an online AAIC presentation.

The list, part of the commission's report on dementia prevention, intervention, and care published simultaneously in The Lancet, expanded the number of potentially preventable causes of dementia in the commission's 2017 report, laying out lifestyle changes and public health policies that may help reduce dementia cases.

"We're very excited to be able to put together and generate evidence about prevention and care which are relevant to all health care professionals in primary and secondary care and public health," Livingston told MedPage Today.

"We all have a part to play in reducing the number of people who develop dementia by tackling risks and in maximizing the health of people with dementia and their families," she said. "We can make a huge difference to individuals, families, and nations."

The report separated modifiable factors into early, mid-, and late-life prevention, with varying attributable risk:

• Early life: poor education (7.1%)
• Midlife: hearing loss (8.2%), traumatic brain injury (3.4%), hypertension (1.9%), excessive alcohol (0.8%), and obesity (0.7%)
• Later life: smoking (5.2%), depression (3.9%), social isolation (3.5%), physical inactivity (1.6%), air pollution (2.3%), and diabetes (1.1%)

"Dementia and Alzheimer's disease are multi-determined," said co-author Lon Schneider, MD, of the University of Southern California in Los Angeles, who spoke about the challenges of dementia care during the presentation.

"We know a single new drug or antibody or even a combination, if successful, will have only limited impact, and is unlikely to exert therapeutic effects as great as our being able to prevent, delay, lower risk, and alter clinical course through multimodal interventions and care," he said.

The authors also listed nine recommendations for policymakers and individuals to reduce dementia risk:

• Aim for systolic blood pressure of 130 mm Hg or less from around age 40
• Encourage hearing aids for hearing loss and reduce hearing loss by protecting ears from high noise levels
• Reduce air pollution and second-hand tobacco smoke exposure
• Prevent head injury, especially in high-risk occupations and transportation
• Prevent alcohol misuse and excessive drinking
• Stop smoking and support individuals to stop smoking
• Provide all children with primary and secondary education
• Lead an active life into midlife and possibly later life
• Reduce obesity and diabetes

"This report suggests that many people have the potential to reduce their risk of cognitive decline, and perhaps dementia, through simple, healthful behavior changes," noted Maria Carrillo, PhD, chief science officer of the Alzheimer's Association in Chicago, who was not involved with the Lancet Commission.

"At a public health level, interventions based on this evidence could be extremely useful in managing the global human and economic costs of Alzheimer's and other dementias," she told MedPage Today. "More research is needed to confirm this hope, and to develop a specific, recommendable 'recipe' to prevent cognitive decline and dementia, including Alzheimer's dementia."

To help identify more precise risk reduction, the Alzheimer's Association is running the U.S. POINTER study, "a 2-year clinical trial to evaluate whether lifestyle interventions that simultaneously target multiple risk factors can protect cognitive function in older adults who are at increased risk for cognitive decline," Carrillo said.

The last Lancet Commission report "made a difference: it changed policy, it changed what individuals did," Livingston pointed out. "We hope this will continue, that it will reduce the number of people with dementia, and give people hope."

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