Better heart health slows brain aging and lowers dementia risk, study finds
New research reveals that older adults who maintain strong cardiovascular health show fewer signs of brain degeneration—offering hope for preventing dementia and Alzheimer’s through heart-smart living.
Study: Cardiovascular Health and Biomarkers of Neurodegenerative Disease in Older Adults. Image Credit: crystal light / Shutterstock.com
A recent JAMA Network Open study investigates the association between cardiovascular health (CVH) and biomarkers of neurodegenerative disease.
The role of CVH in neurodegenerative disease risk
The American Heart Association developed Life’s Simple 7, a seven-item tool to support CVH in the general population by improving physical fitness and diet quality, maintaining a normal body mass index (BMI), and managing diabetes, dyslipidemia, and hypertension. Individuals with a higher Life’s Simple 7 score exhibit optimal CVH and are at a reduced risk of stroke and cardiovascular disease (CVD).
CVDs and neurodegenerative diseases like dementia and Alzheimer’s disease share several common risk factors, some of which include hypertension, hyperlipidemia, metabolic syndrome, and cigarette smoking. Comparatively, optimal CVH may reduce the risk of developing neurodegenerative diseases by slowing the rate of cognitive decline and reducing white matter hyperintensity volumes.
About the study
The current study investigates whether CVH influences several biomarkers of neurodegenerative processes, including serum levels of neurofilament light chain (NfL) and total tau (t-tau). It also measured longitudinal changes in these biomarker levels over a 10-year period to determine whether these alterations vary between Black and White individuals.
Data were acquired from the Chicago Health and Aging Project (CHAP) study, a population-based study that identifies risk factors for Alzheimer’s disease, cognitive impairment, and other types of dementia. The CHAP cohort comprised 10,802 Black and White American individuals who were 65 years or older from the South Side of Chicago. Demographic data, medical history, and serum samples were collected every three years between 1993 and 2012.
A total of 5,470 participants from the CHAP cohort were selected based on their willingness to provide serum samples. Among these individuals, 1,327 samples were randomly selected to measure NfL and t-tau levels.
The CVH score was developed using the Life’s Simple 7 tool, which included different parameters, including BMI, diet, physical activity, diabetes, smoking status, dyslipidemia, and hypertension. Each study participant was assigned a score of zero, one, or two based on their adherence to the seven cardiovascular health factors.
CVH scores ranged from zero and 14 points, with higher scores reflecting superior CVH.
Study findings
A total of 1,018 CHAP study participants were selected for the final analysis. The mean age of this cohort was 73.1 years, 61.4% of whom were female, 59.9% were Black, and 40.1% were White.
Most study participants with a high CVH score between 10 and 14 points were White or reported higher education. Approximately 34.6% of study participants were carriers of at least one apolipoprotein e4 (APOE e4) allele, which reflects a genetic predisposition to developing Alzheimer’s disease.
A higher CVH score was associated with lower serum concentrations of NfL, with a single point increase in CVH scores associated with significantly lower serum levels of NfL. Compared to study participants with CVH scores between zero and 6, individuals with high CVH scores were likelier to have considerably lower levels of NfL. No association between CVH and serum t-tau concentrations was observed for each one-point increase in CVH score.
Higher CVH scores were statistically associated with a reduction in NfL levels among APOE e4 carriers only. These observed associations between CVH and NfL were not dependent on race.
Baseline CVD did not influence the association between CVH scores and NfL levels. Notably, higher CVH scores were associated with a slower annual increase in NfL levels as participants aged. However, the CVH score did not influence annual changes in t-tau concentrations.
Serum NfL and t-tau levels across CVH score ranges were also measured during the 10-year follow-up period. To this end, individuals with the lowest CVH scores experienced an annual increase in NfL levels by 7.1%, whereas those with the highest CVH scores exhibited an annual increase in NfL rates by 5.2%.
Conclusions
Older individuals with better CVH had lower serum concentrations of NfL, irrespective of age, sex, and race. For individuals carrying the APOE e4 allele, a greater CVH score was significantly associated with lower levels of NfL.
These findings emphasize the importance of maintaining optimal CVH to reduce the risk of developing neurodegenerative diseases. This is particularly important in Black adults, who are often at a greater risk of developing CVDs.
Promoting CVH in older adults may help reduce the burden of neurodegenerative diseases.”
