Researchers at the University of California San Diego School of Medicine have received a $24.5 million grant from the National Institutes of Health (NIH)/National Institute on Aging (NIA) to advance the study of Latinos research on neurocognitive aging. (SOL-INCA), a 12-year assessment of cognitive and brain aging and impairment in aging Latinos.

The new SOL-INCA-AD grant continues a nationwide longitudinal study seeking telltale biomarkers of risk and resilience associated with cognitive aging in Latinos of diverse backgrounds.

In the first study, published earlier this year, researchers reported that a higher burden of cardiovascular disease in middle age was significantly associated with increased rates of cognitive decline and prevalent mild cognitive impairment (MCI) among Latinos. The cardiovascular burden varied by Latino ancestry.

Latinos are exposed to early excessive and chronic cardiovascular disease -; especially diabetes -; that may contribute to cognitive decline and the onset of dementia.

SOL-INCA-AD expands the initial study to investigate 10-year cognitive aging and blood-based biomarker pathways in dementia, including variations in cognitive decline, MCI, and Alzheimer’s disease and related dementias (ADRD) in diverse Latinos.

Hector González, PhD, professor of neuroscience at the UC San Diego School of Medicine and co-director of the Latino Core of the UC San Diego Shiley-Marcos Alzheimer’s Disease Research Center, is co-principal investigator of the study.

Charles DeCarli, MD, professor of neurology at UC Davis Health and director of the UC Davis Alzheimer’s Disease Research Center, is co-principal investigator.

Gonzalez said the funding is crucial to better understand the aging brains of diverse Latinos, who make up nearly one-fifth of the US population.

In 2020, Latinos represented 18.7 percent of the U.S. population and nearly 40 percent of the country’s two most populous states, California and Texas. By 2060, the US Census projects a 391 percent increase in Latinos age 65 and older. The Centers for Disease Control and Prevention estimate that the largest increase in ADRD will affect older Latinos, mainly due to an overburden of cardiovascular disease. The new grant makes it possible to upgrade data from now outdated studies.

Studying diverse Latino populations is a neglected field in neuroscience and cognitive brain aging. We really don’t know the neurobiology of various Latinos as we should. This new study allows us to explore genetic, cardio-metabolic and socio-cultural contributions to the aging brain.”

Hector González, PhD, professor of neuroscience, UC San Diego School of Medicine

The researchers said SOL-INCA-AD will collect data that can be translated into real-world therapies, potentially reducing the burden of dementia that affects Latinos.

“We can’t achieve health equity if we don’t have studies to develop the knowledge we need,” says DeCarli of UC Davis Health.

Notably, SOL-INCA-AD will also explore how COVID-19 affects the aging brain and cognitive health of Latinos. DeCarli said COVID-19 could negatively impact normal cognitive aging and increase the risk of dementia.

“COVID-19 is disproportionately impacting Latinos in the US and especially here in California,” González said. “Since SOL-INCA-AD is a longitudinal study, we are in a unique position to understand the effects of COVID-19 on cognitive aging in a large and underexposed population. One possible outcome is the use of disease-modifying therapies, such as novel drugs that are just now coming to market for people experiencing long-term symptoms of COVID-19. I hope we can change the trajectory for stability and improvement.”

SOL-INCA AD is also a partnership with Wayne State University in Detroit, MI. Wayne State University houses the core study in analysis and biostatistics, with Wassim Tarraf, PhD, associate professor of gerontology health sciences, as the principal investigator of the study site.

Tarraf said the study offers an unprecedented opportunity to understand the complex pathways underlying cognitive aging and ADRD in diverse Hispanics and Latinos, from middle age.

“This new funding allows us to delve into both the psychosocial and biological risk and protective factors for cognitive disease in a largely understudied population. It is a great opportunity to expand science and build the next generation of scientists.” lead and involve them in working towards fair, healthy aging.”