Hispanic Brain Aging: NIH Invests Approximately $16 Million in Research

For decades, most of what we know about brain aging has been learned from the white population. But estimates indicate that approximately 13% of Latinos aged 65 and older in the U.S. live with Alzheimer's or another dementia, a rate higher than that among non-Hispanic whites (about 10%), and their lifetime risk is about 50% higher. The reasons are unclear. The NIH believes it is time to investigate them in depth. Consequently, a grant of approximately $15.85 million was awarded to UC Davis Health and UC San Diego to follow about 1,800 Latino adults for about 12 years. This is one of the most comprehensive studies in the world on brain aging in this population and is expected to become a model for future aging research. It is important to note: this is a study that is just beginning, not a result.

The Problem: Most Aging Research is Done on White Populations

For decades, most major studies on Alzheimer's, Parkinson's, and cognitive decline were conducted on white American or European populations. The reasons:

• Access to research clinics: Latinos in the U.S. are less likely to participate in trials, due to issues of trust, language, insurance, and location
• Recruiter biases: Researchers prefer well-documented populations
• Communication barriers: Survey questionnaires in English only
• History of mistrust: Minority communities remember past abuses (Tuskegee, etc.)

The result: Drugs and diagnostic approaches were developed on one population and applied to everyone, even when the biology is different.

Why Do Latinos Develop Dementia More?

The higher rates among Latinos stem from complex reasons:

1. Higher diabetes rates: About 17% among Hispanics vs. about 8% among non-Hispanic whites (CDC data). Diabetes is a proven risk factor for dementia
2. Obesity: About 44.8% among Hispanics vs. about 42.2% among whites, a relatively small but consistent gap
3. Limited healthcare access: The uninsured rate among Hispanics is two to three times higher than among whites
4. Lower average education: Each additional year of education adds brain resilience
5. Mixed genetics: Latinos carry diverse genetic combinations that may affect aging pathways
6. Chronic socioeconomic stress: Many live in polluted environments with constant financial strain

The Trial: About 12 Years, About 1,800 Participants

The study, led by Prof. Charles DeCarli from UC Davis and Prof. Hector Gonzalez from UC San Diego, will include:

• About 1,800 Latino participants (the research announcement does not specify a particular age threshold)
• About 12 years of follow-up
• Repeated MRI scans
• Blood tests for dementia biomarkers
• Cognitive assessments
• Collection of information on lifestyle, diet, physical activity, and stress

The team will build the most comprehensive database in the world on brain aging in Latinos, open to other researchers who can use it. The study relies on the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), one of the largest health databases among Latinos in the U.S., and will be conducted in various regions such as Miami, San Diego, Chicago, and New York.

Interesting Aspects to be Examined

The researchers hope to answer questions that are unclear:

1. Do Alzheimer's drugs work in Latinos? New drugs like lecanemab were developed primarily on white patients. We do not know if they are equally effective in other populations
2. What unique genetic variants exist? There may be variants that are protective or increase risk
3. How do cultural factors influence? The close-knit family tradition among Latinos can be a protective factor (social support) or a burden (caregiving stress)
4. Which interventions are most effective? Diet, physical activity, education – what interventions work in this community?

A Model for Future Studies

This is not the first of its kind, but it is among the most comprehensive. If successful, it will serve as a model for studying other underrepresented populations:

• African Americans (also at increased risk)
• Asians (with unique characteristics)
• Native Americans (massive underrepresentation)
• Impoverished populations in Europe and Australia

The expectation: In years to come, medicine will move from "one-size-fits-all" towards population- and patient-tailored medicine.

Why This is Relevant to Everyone, Even Non-Latinos

Even if you are not Hispanic, the findings will be relevant:

• Shared genetics: Genes that protect Latinos may also work in others
• Cross-cutting risk factors: Diabetes, obesity, and stress exist in everyone
• Broader understanding: Understanding aging in one community helps understand aging in general

How to Participate?

Those interested in participating and meeting the criteria can register through the university websites. The team is seeking a diverse range of regions, ages, and health statuses (both healthy individuals and those with cognitive decline). Participation includes free tests throughout the study. Many hope the study itself will contribute to their health.

Implications for Treatments

If the study reveals that certain drugs work less effectively in Latinos, pharmaceutical companies will need to develop adapted versions. This may increase costs but improve outcomes. The expectation: Some drugs will go back to the drawing board with adjustments.

The Bottom Line

This study is a vital step in the evolution of medicine. We are approaching an era where "one drug for Alzheimer's" will not be the only answer. Instead, there may be different approaches for different populations, based on genetics and lifestyle. In the future, a doctor saying "this drug works differently in this group" will sound normal. But to get there, someone needs to do the work. The NIH and UC are doing it now.