Physical activity and healthy blood sugar levels during midlife may be linked to a significantly slower decline in thinking abilities later in life, according to new research from UT Health San Antonio, the academic health center of The University of Texas at San Antonio. The findings suggest that exercise may be especially important for Hispanic adults.
Scientists already know that cardiovascular problems in midlife can raise the risk of cognitive decline and dementia. This study is among the first to investigate how specific cardiovascular health factors may relate to cognitive aging across different ethnic groups.
Researchers analyzed 402 people from San Antonio. Of the participants, 52% were Hispanic, and the rest were non-Hispanic white. Their mean age was 57.9, and 58.5% were women.
The findings varied by ethnicity. Physical activity was particularly associated with slower cognitive decline among Hispanic participants, while lower fasting blood glucose levels were linked to slower cognitive decline among non-Hispanic white participants.
“By improving cardiovascular health through modifiable lifestyle changes, there is a potential to meaningfully alleviate the public health burden of Alzheimer’s disease and other dementias, particularly in high-risk populations,” said Claudia Satizabal, PhD, associate professor in the Department of Population Health Sciences at UT Health San Antonio and its Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, where she leads the Population Neuroscience Core.
Satizabal is co-senior author of the study with Chen-Pin Wang, PhD, associate professor-research in the Department of Population Health Sciences. The research, titled “Longitudinal association between midlife cardiovascular health and cognitive change in a bi-ethnic cohort,” was published July 23 by Alzheimer’s & Dementia: Behavior & Socioeconomics of Aging.
All of the study authors are affiliated with either the Glenn Biggs Institute or The University of Texas Rio Grande Valley.
Cardiovascular Health and Dementia Risk
As people around the world live longer and the proportion of older adults grows, age-related conditions such as dementia are becoming increasingly common. The study notes that 6.7 million people in the United States currently have Alzheimer’s disease.
At the same time, research increasingly suggests that many risk factors for cognitive decline and dementia can be modified. Recent estimates indicate that nearly 40% of Alzheimer’s cases may be connected to such factors. Cardiovascular health, in particular, has emerged as an important influence on how the brain ages.
One widely used approach for measuring cardiovascular health is the American Heart Association’s Life’s Simple 7 (LS7) framework. It includes three behavioral factors (healthy diet, non-smoking, and physical activity) and four health factors (blood pressure, body mass index, total cholesterol and fasting blood glucose). According to the study, LS7 provides an overall measure of cardiovascular health and has also been proposed as a way to support better brain health.
Previous research has found that stronger adherence to LS7 is associated with better cognitive performance, healthier brains, and a lower risk of dementia. However, these relationships do not appear to be identical across different populations.
Hispanic older adults face a disproportionate burden of Alzheimer’s disease and related dementias. About 14% of Hispanic adults aged 65 or older have Alzheimer’s, compared with 10% of non-Hispanic white older adults. Mexican Americans, who make up the largest Hispanic population in the United States, also have particularly high rates of diabetes, obesity and dyslipidemia, conditions that can increase dementia risk.
Why South Texas Offers Important Insights
Despite these disparities, Hispanic populations remain underrepresented in Alzheimer’s research. The researchers note that this lack of representation makes it more difficult to understand how dementia risk develops over time and to identify prevention strategies that may work effectively for everyone.
To help address that gap, the UT Health San Antonio team investigated the relationship between cardiovascular health in midlife, measured through LS7 scores, and later cognitive decline among Mexican American and non-Hispanic white older adults. The participants had previously taken part in the San Antonio Heart Study (SAHS) and the San Antonio Longitudinal Study of Aging (SALSA).
The SAHS was a landmark, long-term project led by UT Health San Antonio to investigate the causes of Type 2 diabetes and heart disease. Conducted from 1979 through the 2000s, the project followed more than 5,000 people to better understand why certain ethnic populations experience higher health risks.
SALSA later grew out of that work. Also conducted by UT Health San Antonio, it became a major, long-term observational study focused on chronic diseases, healthy aging and the process through which older adults develop disabilities. Its participants had previously been enrolled in the SAHS.
“Importantly, the inclusion of both ethnic groups from the same source population and geographic setting allows for direct comparison within a shared contextual framework and strengthens our ability to identify disparities in cognitive aging and their cardiovascular correlates,” the new study notes.
Tracking Cognitive Changes Over Time
For the new analysis, researchers evaluated cardiovascular health among SAHS participants who were later enrolled in SALSA, using their LS7 scores.
Cognitive ability was measured as many as four times with the Mini-Mental State Examination, an established 11-question screening test that evaluates memory, attention and thinking skills.
The team also used generalized estimating equation models to examine how cardiovascular factors were related to changes in cognition. The statistical models accounted for age, sex, income, and education.
Researchers additionally performed sensitivity analyses to assess attrition bias. These extra statistical checks were designed to determine whether people dropping out of the study could have distorted the final results.
Exercise and Blood Sugar Show Different Links
The analysis found that engaging in any physical activity, rather than living a sedentary lifestyle, was particularly associated with slower cognitive decline among Mexican Americans.
Fasting glucose also emerged as an important factor. This measurement reflects the amount of sugar in the blood after an eight- to 12-hour fast. Among non-Hispanic white participants, fasting glucose readings of 126 milligrams per deciliter or lower were associated with a slower rate of cognitive decline.
“Our findings suggest that engaging in any level of physical activity and potentially maintaining optimal fasting blood glucose levels in midlife are associated with a significantly slower rate of cognitive decline in late life,” said Janette Vazquez, PhD, first author of the study and currently a senior postdoctoral fellow at the Glenn Biggs Institute. But since the results differed by ethnicity, further research is needed in larger samples to replicate the differences, she said.
The findings suggest that cardiovascular health during midlife could influence cognitive aging many years later, but they also indicate that the most important factors may not be the same for every population.
“The longitudinal exploration of cardiovascular health throughout life, rather than assessing it at a single time point, could also provide further insight into the trajectory phenotypes contributing to cognitive decline by ethnicity,” Vazquez said.
Participants from the study are now being invited to join the San Antonio Heart and Mind Study (SAHMS) at the Glenn Biggs Institute. Researchers hope the ongoing project will generate additional discoveries by collecting state-of-the-art brain imaging and other neurological data.
