Alzheimer’s disease remains a major health concern in the San Joaquin Valley, ranking as the fifth leading cause of death in the region between 2019 and 2023. According to data from the U.S. Centers for Disease Control, only heart disease, cancer, COVID-19, and accidents claim more lives.
Five counties in the San Joaquin Valley—Tulare, Fresno, Kern, Madera, and Stanislaus—are among California’s top ten counties with the highest Alzheimer’s mortality rates. Tulare County leads with an annual rate of 61.6 deaths per 100,000 people, followed by Fresno (57.5), Kern (56.0), Madera (51.9), and Stanislaus (46.1).
Despite these high numbers overall, Hispanic or Latino residents in the Valley experience significantly lower Alzheimer’s mortality rates compared to non-Hispanic whites. Data from the National Institute on Minority Health and Health Disparities shows that from 2019 through 2023, white residents had an average annual Alzheimer’s mortality rate that was 17.5 deaths per 100,000 higher than their Hispanic or Latino counterparts.
The reasons behind this disparity are not fully understood. However, researchers have suggested several possible factors.
Gender also plays a role in Alzheimer’s mortality rates. Research published in Cellular and Molecular Life Sciences in 2021 found that almost two-thirds of Alzheimer’s patients are women. The study identified several contributing factors for women’s higher risk: differences in brain structure and stress responses; pregnancy; menopause; sex hormones; vascular disorders; as well as socioeconomic conditions such as lower income and education levels compared to men.
“Women live longer than men on average of 4.5 years, and there are more women aged 85 years or older than men in most global subpopulations, while older age is the greatest risk factor” for Alzheimer’s disease,” wrote Donghui Zhu of Stony Brook University, Axel Montagne of the University of Edinburgh, and Zhen Zhao of USC Keck School of Medicine.
“Women usually have a lower income and lower education than men in most cultures, and they are the primary informal caregivers in their families,” Zhu, Montagne and Zhao added. “The caregiving burden is associated with higher rates of unemployment and an increased psychological risk factors in (Alzheimer’s) including depression and sleep disorders.”
Researchers at Mayo Clinic have noted another possible explanation: “One explanation is that men may die of competing causes of death earlier in life, so that only the most resilient men survive to older age,” according to a January 2014 article in Clinical Epidemiology.
For Latinos or Hispanics’ lower mortality rates from Alzheimer’s disease compared to non-Hispanic whites, bilingualism has been cited as one potential protective factor.
A study published by Gannan Medical University researchers Haiqing Liu and Longhuo Wu in Frontiers in Psychiatry stated: “Bilingualism has been reported to significantly delay the onset of dementia and plays an important role in the management of Alzheimer’s disease.” They added: “Effectively, bilingualism can be considered as a pharmacological intervention (for Alzheimer’s) with no side effects.”
A summary from the February 2022 issue of Alzheimer’s & Dementia highlighted findings from the Alzheimer’s Association’s Latinos & Alzheimer’s Symposium: “As language experience powerfully shapes brain and cognitive function, bilingualism may play an important role in one’s protection or risk to develop dementia later in life.” The report noted that about 59% of Latino adults living in the U.S. are bilingual.
“One idea is that bilingualism may build cognitive reserve, which would allow the brain to better cope in the face of [Alzheimer’s disease and related dementia] changes,” symposium researchers said.
However, experts caution that despite current trends showing lower mortality rates among Latinos for now, projections indicate this population could see a steep increase over coming decades due to underrepresentation in research studies and clinical trials; limited access to quality healthcare; language barriers; lower educational attainment; poverty; and other socioeconomic challenges.
