Studying Alzheimer’s in Southern Chile

As a student of public health, José Aravena Castro is interested in how cultural and societal influences affect our brains as we age. When his professor at the University of Chile introduced him to research by Yale Professor Becca Levy that found that memory loss is not inevitable, Aravena took note. Now a doctoral student at YSPH, he is studying issues related to Alzheimer’s disease and memory loss among members of an indigenous community in Chile.

Levy’s findings were, “so new, so cool in so many ways,” he said.

Aravena was accepted as a doctoral student at Yale School of Public Health in the Department of Social and Behavioral Sciences where Levy is a professor, and now, the chair of his dissertation committee and his research mentor.

"I’m delighted to work with Jose. He is very creative, smart, and passionate about conducting research that can improve older persons' health," said Levy, who has found through her research that health problems thought to be entirely due to aging, such as memory loss, hearing decline, and cardiovascular events, are influenced by negative age beliefs. Positive age beliefs lead to better health and even longer life, her research shows.

Aravena is conducting fieldwork for his dissertation among members of the indigenous Mapuche community of southern Chile. A Fulbright scholar, he has received support for his dissertation from the Chilean National Research and Development Agency (ANID); the MacMillan International Dissertation Research Fellowships from the Yale MacMillan Center for International and Area Studies; the Yale University Council on Latin American and Iberian Studies; and the Yale Department of Social and Behavioral Sciences Research Fund.

Aravena is interested in whether people who have lower exposure to adverse social determinants of health have a lower risk of having dementia even if they have the gene variant associated with Alzheimer’s, APOE e4. He is also looking at whether people who are more exposed to adverse social determinants of health have a higher risk of developing Alzheimer's disease even if they have the protective Alzheimer’s gene, APOE e2. Social determinants of health are those conditions of life that influence a person’s health, such as income, education, housing, and job insecurity.

Yale School of Public Health Associate Professor Xi Chen, an affiliate of Yale’s Alzheimer’s Disease Research Center, is also Aravena’s mentor. Together they are analyzing data from two countries: the Health Retirement Study (HRS) from the United States and the English Longitudinal Study of Aging (ELSA) from England. The two studies measure similar psychosocial and health parameters, allowing for cross-country comparisons.

“As the world still has no effective treatment for dementia, and a number of risk factors in our life course may shape brain health and therefore dementia vulnerability, it would be very important to better understand social determinants of dementia risk, like what Jose attempts to achieve through his doctoral research, to prevent or delay the onset of dementia,” said Chen.

Aravena plans to develop an intervention to address social determinants of brain health that is based on the information and findings from this study and his research among the Mapuche and non-Mapuche adults. “Since culture may influence our views, beliefs, and behaviors toward brain health, developing tailored and culturally pertinent interventions is critical to achieving positive results,” Aravena said.

According to Chen, dementia is widely stigmatized across the globe. “Even in developed societies, dementia has been underdiagnosed, partially due to the negative attitudes,” Chen said. “Minority groups are less likely to seek diagnoses when they have memory-related issues.”

Aravena chose the Mapuche for his dissertation as there is a gap in the study of Latin American indigenous groups regarding their perceptions and needs around health-related topics, he said. Also, the Mapuche are at greater risk of dementia than non-Mapuche older adults, he added. To understand how culture may influence our beliefs and behaviors toward brain health, Aravena plans to contrast Mapuche views about memory loss and how to achieve a healthy aging brain with the views of non-Mapuche older adults.

“Last week I had an interview with 97-year-old women and her best friend who is 90 years old[JD2] [ja3] ,” he said. “They never have talked about these things before. Nobody’s asked. We’ve created a lot of points of reflection for them.”

Aravena has found that 90 percent of the people he has interviewed, Mapuche and non-Mapuche, said dementia is a normal part of the aging process. Among his questions is whether a younger person or an older person is more capable of problem solving, and whether an older person or a younger person has more capacity to learn something new.

“Most believe that older people are better at solving problems because they have wisdom and the calm required to think of the best solution to a problem,” Aravena said. “It makes me think how much of their belief of memory loss as being a normal part of aging comes from observations that they have had of older people living with dementia or Alzheimer's disease,” he said. “They do not necessarily think that older people cannot solve problems or cannot learn things compared to someone who is younger.”

Positive age beliefs emerged spontaneously in his conversations with the Mapuche, who stressed the importance of having a positive attitude. “For them, not feeling older is something that protects you and keeps you working or keeps you engaged and interested in the things that you do.”

According to Chen, population-level studies can identify additional risk factors of dementia, such as low education, exposure to air pollution, head injury, smoking, excessive alcohol use, hypertension, hearing loss, obesity, depression, physical inactivity, diabetes, and social isolation. These risk factors are modifiable and should be targeted with Individually tailored interventions, Chen said. Interventions also should target high-risk groups that have these identified risk characteristics. Care programs should consider the whole person. “For example, psychosocial interventions may tailor to the patient’s needs, to manage neuropsychiatric symptoms that may worsen cognitive ability,” Chen said.

Some of the members of the Mapuche community told Aravena that Alzheimer's disease or memory problems in older adulthood is due to having experienced traumatic events during their lives. They described this as “carrying a big sadness.” But as a person ages, they cannot sustain the big sadness that they have carried. “At that point, the person maybe decides that it is better to go away in their mind to forget all those traumatic experiences,” Aravena said.

Many of the indigenous people Aravena spoke to believe that you can't prevent Alzheimer’s disease. “It is something that arrives in your life and that's it, you are kind of destined to have Alzheimer’s and there's no possibility to reduce the risk,” he said.

“All these people that we have interviewed, they’ve never participated in a research study -- they’ve never been invited to participate in something like this,” Aravena said. “And all of them feel extremely grateful to have this chance.”