Two separate studies looking at dementia rates found a drop in diagnoses over time due to higher education and decreased smoking levels but an increase in potential early-onset dementia in Native populations.
Falling dementia rates amid rising risk factors
In a recent study published in The Lancet, a research team led by University of College London analyzed the results of 27 previous studies examining changes in dementia prevalence or incidence between 1947 and 2015. The investigators said that theirs was the first review and analysis of evidence on the prevalence and incidence of dementia with contributing risk factors.
Their findings pointed to increased education and reduced smoking rates — likely due to reduced social acceptance, higher costs, less advertising and smoking bans in public places — as likely contributors to a decrease over time in the proportion of people in whom dementia had been diagnosed.
But the researchers raised concerns about the prevalence of other risk factors that contribute to dementia diagnoses, including hypertension, diabetes and obesity — the rates of all of those risk factors increased over time.
The authors said that their findings suggest that lifestyle interventions, including compulsory education and national policy change to reduce smoking rates, as well as targeted interventions to reduce other risk factors, could further reduce the incidence of dementia.
Future studies, they said, could use population-level modeling to forecast the effects of public health interventions and changes in risk factors on projected future dementia diagnosis. They also called for additional studies in low-income and middle-income countries, where the burden of dementia is highest and continues to increase.
The study was funded by the National Institute for Health and the Care Research Three Schools’ Dementia Research Programme.
Reducing dementia risk in Native populations
In another study published last month in the Journal of the American Geriatrics Society, researchers from the Indian Health Service and the Centers for Disease Control and Prevention raised the alarm about high rates of early-onset dementia diagnoses in American Indian/Alaska Native populations.
Using healthcare data from 2016 to 2020 from the Indian Health Service National Data Warehouse, the investigators identified 12,877 American Indian/Alaska Native adults aged 45 or more years who had an Alzheimer’s disease or related dementia diagnosis code in their medical files — an overall rate of 514 diagnoses per 100,000 people. The fact that 14% of those individuals fell in the 45-to-64 age range suggested high rates of early-onset dementia, they said.
An estimated 38,000 American Indian/Alaska Native older adults were living with ADRD in 2020 — a number expected to double by 2030 and quadruple by 2050, according to the Indian Health Service.
The study is the first to provide estimates of Alzheimer’s disease and related dementias in those populations, the researchers said, noting that those individuals receive medical care at through the Indian Health Service, tribal and urban programs, which highlights the need for risk reduction interventions for common comorbidities of diabetes and cardiovascular disease.
“This study provides baseline data to assist Indian Health Service, CDC, and other public health and tribal partners in addressing ADRD in American Indian and Alaska Native communities,” the authors concluded. “The findings emphasize the need for implementation of ADRD risk reduction strategies and the need to screen and diagnose ADRD in younger populations, and enhance clinical and community-based services to support American Indians/Alaska Natives living with dementia and their caregivers.”
Designing care and services to meet the needs of the American Indian/Alaska Native people living with ADRD should come from the history, culture and values of the sovereign tribes, nations and urban communities in which they live, the researchers stated. Culturally relevant and appropriate clinical and community-based services are necessary to support such people and their caregivers, they added.
