By Megan Brooks

Nearly half of all US adults aged 45 and older have modifiable risk factors for Alzheimer's disease and related dementias (ADRD), including hypertension, low levels of physical activity, and obesity, new research shows.

Data from the Centers for Disease Control and Prevention (CDC) reveals that among nearly 162,000 adults aged 45 and older who were surveyed in 2019 as part of the Behavioral Risk Factor Surveillance System (BRFSS), nearly half had high blood pressure and did not achieve aerobic physical activity recommendations. These were the two most common modifiable risk factors for ADRD.

In addition, more than one third (35%) of adults were obese, 19% had diabetes, 18% had depression, 15% were smokers, 11% had hearing loss, and 10% were binge drinkers.

The findings were published online May 19 in the CDC's Morbidity and Mortality Weekly Report.

A Missed Prevention Opportunity

More than 1 in 10 (11.3%) adults surveyed reported subjective cognitive decline (SCD), an early indicator of possible future ADRD.

The prevalence of SCD increased from about 4% among adults with no modifiable risk factors for ADRD to 25% for those with four or more risk factors.

Adults with SCD were more apt to report having almost all modifiable risk factors and were more likely to report four or more risk factors (34%) than peers without SCD (13%).

The prevalence of SCD ranged from a high of about 29% in those with depression and 25% in those with hearing loss to 11% in those who reported binge drinking.

In line with previous research, the findings indicate that American Indian or Alaska Native, Black or African American, and Hispanic populations were more likely to have modifiable risk factors for ADRD than other racial groups, the researchers report.

The CDC's National Healthy Brain Initiative supports culturally tailored interventions that address ADRD risk factors specifically in these populations.

In 2021, the federal government's National Plan to Address Alzheimer's Disease was updated to include a new goal to reduce risk factors for ADRD.

"Given the prevalence of modifiable risk factors for ADRD and anticipated growth of the older adult population and those with ADRD, this new goal has the potential to benefit a large proportion of US adults," the investigators write.

"In addition to helping patients discuss concerns about memory loss, health care professionals should also screen patients for modifiable risk factors, counsel patients with risk factors, and refer them to effective programs and interventions where recommended," they advise.

As previously reported, it was found that modifying 12 risk factors over the life course could delay or prevent 40% of dementia cases.