Physical Activity and Blood Sugar Linked to Cognitive Health in Midlife

Researchers at UT Health San Antonio have found that engaging in regular physical activity and maintaining healthy blood sugar levels during midlife may significantly slow the decline in cognitive abilities later in life, particularly among Hispanic adults. This study is notable for being one of the first to explore how various cardiovascular health factors influence cognitive aging across different ethnic groups.

The study analyzed 402 participants from San Antonio, comprising 52% Hispanic individuals and 48% non-Hispanic white individuals, with a mean age of 57.9 years. Notably, 58.5% of the participants were women. Findings revealed that physical activity was significantly linked to slower cognitive decline in Hispanic participants, while among non-Hispanic white participants, lower fasting blood glucose levels were correlated with reduced cognitive decline.

“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 Dr. Claudia Satizabal, associate professor in the Department of Population Health Sciences and co-author of the study. The research was published on July 23 in the journal Alzheimer’s & Dementia: Behavior & Socioeconomics of Aging.

As life expectancy increases, age-related conditions such as dementia are becoming more prevalent. The study highlights that approximately 6.7 million Americans are currently diagnosed with Alzheimer’s disease. It emphasizes that a substantial portion of Alzheimer’s cases—estimated at nearly 40%—could be associated with modifiable risk factors, particularly cardiovascular health, which plays a significant role in brain aging.

To measure cardiovascular health, the study utilized the American Heart Association’s Life’s Simple 7 (LS7) framework, which assesses both behavioral and health-related factors, including physical activity, diet, blood pressure, body mass index, total cholesterol, and fasting blood glucose. Stronger adherence to LS7 components has been previously linked with better cognitive function and a reduced risk of dementia; however, these relationships are not uniform across all populations.

Hispanic older adults represent a demographic disproportionately affected by Alzheimer’s disease, with about 14% of Hispanic adults aged 65 or older diagnosed, compared to 10% of their non-Hispanic white counterparts. Mexican Americans, who constitute the largest Hispanic group in the U.S., also have higher rates of diabetes, obesity, and dyslipidemia, which are conditions known to elevate dementia risk.

The underrepresentation of Hispanic populations in Alzheimer’s research poses challenges in understanding the evolving risk factors for dementia and developing effective preventive strategies. Addressing this gap, the UT Health San Antonio study examined cardiovascular health in midlife—quantified through LS7 scores—and its impact on cognitive decline among both Mexican American and non-Hispanic white older adults, many of whom participated in earlier studies such as the San Antonio Heart Study (SAHS) and the San Antonio Longitudinal Study of Aging (SALSA).

Data collection in SAHS, a pioneering long-term study conducted from 1979 through the 2000s, provided insights into the causes of Type 2 diabetes and heart disease. SALSA subsequently focused on chronic disease and healthy aging, building upon SAHS findings. The research notes the significance of including diverse ethnic groups within the same geographic area to strengthen comparative analyses regarding cognitive aging and cardiovascular health disparities.

The researchers measured cognitive ability up to four times using the Mini-Mental State Examination, a respected tool for assessing memory and cognitive function. They employed generalized estimating equation models to explore how changes in cardiovascular health correlated with cognitive performance while controlling for various factors, including age, sex, income, and education.

The study found that for Mexican Americans, any level of physical activity was associated with a slower cognitive decline. For non-Hispanic whites, maintaining fasting glucose levels at 126 milligrams per deciliter or lower positively correlated with cognitive stability. “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 Dr. Janette Vazquez, the study’s first author.

The study indicates that factors influencing cognitive aging may differ across populations, highlighting the need for further research with larger samples to confirm these ethnic-specific findings. Participants from this study are now invited to be part of the San Antonio Heart and Mind Study at the Glenn Biggs Institute, where researchers aim to gather comprehensive neurological data to foster additional discoveries in the field.