Physical activity and healthy blood glucose levels during middle age may be linked to significantly slower decline of cognitive abilities years later, according to research from UT Health San Antonio, the academic health centre 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 middle age can increase the risk of cognitive decline and dementia. This study is among the first to investigate how specific cardiovascular factors may relate to cognitive ageing across different ethnic groups.
The researchers analysed 402 people from San Antonio. Of the participants, 52% were Hispanic and the remainder non-Hispanic white. Their average age was 57.9 years, and 58.5% were women. The findings varied by ethnicity: physical activity was particularly associated with slower cognitive decline among Hispanic participants, whilst lower fasting glucose levels were linked to slower cognitive decline among non-Hispanic white participants.
"By improving cardiovascular health through modifiable lifestyle changes, there is the possibility of significantly alleviating the public health burden of Alzheimer's 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 at the Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, where she leads the Population Neuroscience Core.
Satizabal is co-lead author of the study alongside Chen-Pin Wang, PhD, associate research professor in the Department of Population Health Sciences. The study, entitled "Longitudinal association between midlife cardiovascular health and cognitive change in a biethnic cohort," was published on 23 July by Alzheimer's & Dementia: Behavior & Socioeconomics of Aging.
As people worldwide live longer and the proportion of older adults grows, age-related conditions such as dementia become increasingly common. The study notes that 6.7 million people in the United States currently have Alzheimer's. At the same time, research increasingly suggests that many risk factors for cognitive decline and dementia may be modifiable. Recent estimates indicate that nearly 40% of Alzheimer's cases may be connected to these factors. Cardiovascular health, in particular, has emerged as an important influence on how the brain ages.
A widely used approach to measuring cardiovascular health is the American Heart Association's Life's Simple 7 (LS7) framework, which includes three behavioural factors (healthy diet, not smoking and physical activity) and four health factors (blood pressure, body mass index, total cholesterol and fasting 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 found that greater adherence to LS7 is associated with better cognitive performance, healthier brains and lower risk of dementia. However, these relationships do not appear to be identical across different populations. Older Hispanic adults face a disproportionate burden of Alzheimer's and related dementias: approximately 14% of Hispanic adults aged 65 or older have Alzheimer's, compared with 10% of older non-Hispanic white adults.
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 work effectively for everyone. To help close that gap, the UT Health San Antonio team investigated the relationship between cardiovascular health in middle age, measured through LS7 scores, and later cognitive decline among older Mexican American and non-Hispanic white 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 to the 2000s, the project followed more than 5,000 people to better understand why certain ethnic populations experience greater health risks. SALSA subsequently emerged from that work. Also conducted by UT Health San Antonio, it became an important long-term observational study focused on chronic diseases, healthy ageing and the process by which older adults develop disabilities. Its participants had previously been enrolled in the SAHS.
Cognitive capacity was measured up to four times using the Mini-Cog, an established 11-question screening test that evaluates memory, attention and thinking skills. The team also used generalised estimating equation models to examine how cardiovascular factors were related to changes in cognition.