American Indian and Alaska Native adults in California struggle with chronic disease and substance use, study finds

Although American Indian and Alaska Native (AIAN) adults make up 5% of California's adult population, they shoulder a disproportionate weight of chronic disease and substance use, according to a new study from the UCLA Center for Health Policy Research (CHPR).

Yet these rates vary widely within the AIAN population when examined by education level, household income, sexual identity and gender identity, according to data from the 2020-2024 California Health Interview Surveys (CHIS). Researchers say the results demonstrate how state population averages can mask important disparities and may interfere with the effectiveness of public health programming.

"Historical trauma, systemic racism and unequal access to education and quality healthcare have contributed to significant health inequities among American Indian and Alaska Native communities," said Alex Bates, CHIS senior data analyst and lead author of the study.

The new research is the first in a series of projects funded by the California Rural Indian Health Board, Inc. (CRIHB) California Tribal Epidemiology Center (CTEC) that examines the health of American Indian and Alaska Native populations in the state. The UCLA CHPR publications, co-authored by CRIHB's Nicamer Tolentino and Antoinette Medina, include a policy brief and two fact sheets that examine chronic conditions and substance use among AIAN groups.

"Our research reveals how social and demographic factors shape health outcomes within the American Indian and Alaska Native community," said Susan Babey, director of research at the UCLA CHPR and one of the study's co-authors. "Identifying those groups carrying the greatest health burden can help practitioners and policymakers design and direct resources to public health programs that better meet their needs."

Disaggregating data about American Indians and Alaska Natives sheds light on health disparities

The study provided insights into how many AIAN adults in California reported hypertension (25%), uncontrolled blood pressure (19%), diabetes (12%), heart disease (6%), binge drinking (21%), marijuana use (19%) and cigarette smoking (8%). But when researchers disaggregated the data (examined it by specific demographic characteristics), they saw substantial disparities across groups within the AIAN population.

Among these disparities were:

• Education: More than 1 in 4 AIAN adults with a high school diploma or less (28%) reported living with hypertension, compared with 19% of those holding a college degree. They were also nearly twice as likely to report diabetes (14% versus 8%).
• Income: Lower-income adults reported higher rates of uncontrolled blood pressure and diabetes and were more likely to smoke cigarettes. In contrast, binge drinking was more common among high-income adults, with 25% reporting drinking four or more drinks on one occasion (five or more for men) during the past month.
• Sexual identity and gender identity: Lesbian, gay, bisexual, pansexual, or another nonheterosexual identity (LGBP+) adults experienced uncontrolled blood pressure at more than twice the rate of heterosexual adults (37% versus 16%). Nearly one-third reported using marijuana in the past month compared with 19% of AIAN adults overall and 18% of heterosexual AIAN adults. Also, while 45% of transgender and gender-expansive adults reported recent marijuana use, only 15% of cisgender AIAN women did and 22% of cisgender AIAN men did. Gender-expansive refers to individuals whose gender identities do not conform to the man/woman gender binary.

What challenges do American Indian and Alaska Native adults face in managing chronic disease?

Nearly one-third of AIAN adults reported living with hypertension, heart disease or diabetes, and 1 in 10 reported living with at least two of these conditions. Although more than two-thirds of adults living with hypertension reported taking prescribed medication, nearly 1 in 5 had uncontrolled blood pressure.

Researchers also found a decline in diabetes medication use, from 85% in 2020 to 62% in 2024, raising concerns about obstacles to ongoing treatment.

Reducing health inequities among AIAN adults in California will require coordinated strategies that address both chronic disease and substance use while recognizing the effects of historical and ongoing trauma, the study emphasized.

"This research reinforces what Tribal communities have long experienced: American Indian and Alaska Native people continue to face disproportionate burdens of chronic disease and substance use," said Virginia Q. Hedrick, CEO of CRIHB. "It underscores the urgent need to invest in Tribal health systems and culturally rooted, community-responsive programs that are designed by and for Native communities."

What should policymakers do to help minimize disparities in chronic disease and substance use faced by American Indian and Alaska Native adults in California?

The authors advise prioritizing research and resources for AIAN adults with lower incomes and less education, and for LGBTQ+ populations, who face some of the greatest burdens identified in the study.

State and federal funding should expand access to culturally responsive preventive care, behavioral health services, and chronic disease treatment, while supporting AIAN-focused recovery and wellness programs designed and led by Tribal nations and Tribal Elders, they added.

"Strategic investments, informed by community-level data and developed in partnership with AIAN communities, offer the greatest opportunity to reduce health inequities and improve health outcomes across California," Babey said.

Because hypertension, heart disease and diabetes often occur together, the authors also recommend integrating prevention and management strategies that combine screening, treatment, education and care coordination to improve health outcomes and reduce barriers to care.