Several studies presented at the Alzheimer’s Association International Conference (AAIC) 2022, held July 31 to August 4 in San Diego, California focused on the intersection between socioeconomic status and cognition, finding that greater deprivation increased risk for dementia and cognitive decline.
The investigators at the University of Luxembourg in Esch-sur-Alzette evaluated 10-year follow-up data from the UK Biobank (N=196,368) and compared socioeconomic deprivation with genetic risk and brain imaging data. They found that both genetic risk and socioeconomic deprivation were independently associated with dementia risk. Among individuals with high genetic risk and individual-level deprivation, 1.78% (95% CI, 1.50-2.09) developed dementia during follow-up compared with 0.31% (95% CI, 0.20-0.45) among those with low risk for both measures.
In a second study, researchers at the University of Texas Southwestern Medical Center in Dallas evaluated data from the Dallas Heart Study Phase 2. This cohort comprised 3858 participants, 51% of whom were Black and 14% were Hispanic. They found that economic adversity is associated with lower cognitive scores. Among the Black participants, economic adversity accounted for more variance in cognitive scores than education or income, and for Hispanic participants, more variance than income. No such relationships were observed among White participants.
In a study assessing memory among middle-aged adults, investigators at Columbia University Irving Medical Center in New York City sourced data from a longitudinal community-based study of Manhattan residents. Middle-aged adult children (n=1038) of older parents (n=694) were found to have lower delayed recall with higher pTau181 concentrations (β, -0.438; P <.001). The relationship between pTau181 and delayed recall was stronger among participants with lower parental socioeconomic status (β, -0.477; P =.019) than among those with higher parental socioeconomic status (β, -0.291; P <.022), indicating early life socioeconomic status likely has an effect of later life cognition.
To evaluate the effect of salary on memory decline, investigators at Columbia University Mailman School of Public Health in New York City sourced data from the 1992 to 2016 Health and Retirement Study. Memory function among 1913 men and 1890 women measured between 2004 and 2016 was compared with wages earned between 1992 and 2004. Both men and women who had sustained low wages over 10 years in mid-life experienced more rapid memory decline (β, -0.12) compared with individuals who never earned a low wage.
Socioeconomic status can also affect access to nutrition. A study conducted at the University of São Paulo Medical School in Brazil interrogated the effect of consuming ultra-processed foods (UPF) on cognitive performance. The 8160 participants in the ELSA-Brasil study were stratified into quintiles on the basis of how much of their diet comprised UPF. The high-UPF consumers were found to have a poorer executive function (β, -0.007; P =.004) and memory performance (β, -0.004; P =.048) during the 9-year follow-up.
Altogether these data emphasized that the conditions individuals experience throughout their life are all important factors and likely impact brain health.
We spoke with Rebecca Edelmayer, PhD, the Alzheimer’s Association Senior Director of Scientific Engagement about an individual’s life experiences and brain health.
There are several studies being presented this year at AAIC 2022 that are looking at the intersection between socioeconomic status and cognitive decline. What is your opinion about the motivation behind the current interest in this topic?
Dr Edelmayer: We are continuing to study risk for Alzheimer’s and all other dementias from all angles. That includes not only biological reasons but also other potentially modifiable factors. Socioeconomic status is one of those factors. That is to say, reflective of both the social and economic measures of a person’s work experience, their family, economic access to resources, and quality health care. I think we’re seeing more and more research that’s delving into how these factors impact risk which may ultimately help us to develop sustainable strategies for interventions and risk reduction.
From a scientific perspective, how can the topic of socioeconomics be addressed, as socioeconomic status affects many things, such as access to education, health care, and nutrition, among others? How can researchers really get at what mechanism is that is causing the effect?
Dr Edelmayer: Researchers around the world have been studying socioeconomic status across cultures and countries for many years, and it’s been linked to both physical and psychological health and well-being. However, we’ve seen very little research, up until more recently, about how socioeconomic status, particularly in early and mid-life, might impact our brains later in life. I think that’s really the unique angle that we’re seeing, presented at the AAIC this year. We’re looking across different studies that are conducted in different populations across the world. Being able to draw from and harmonize results from these different countries is going to be important to help develop policy changes or practical strategies to address some of these socioeconomic conditions in different communities.
What do you think the implications from these studies are for clinical practice? Typically, people who are socially and economically disadvantaged tend to have less access to health care. If these populations are not interacting with the health care system, how can clinicians intervene and improve their trajectory?
Dr Edelmayer: This is really important, and we must address it. We know that not every individual is interacting with the health system in the exact same way and there are definitely quality differences in the types of health care that are being provided. While socioeconomic status, I would say, might be a modifiable risk factor, it also doesn’t mean that people can change their status. There are structural and systemic issues that are at play that can inhibit an individual’s ability to get a job, make more money, and own a car or a home. We can’t necessarily put the onus on the individual when it comes to socioeconomic status. We need to be thinking about this more from a policy perspective that will help improve socioeconomic conditions for all. This is going to be different across communities on a local level, across countries, and on a global level.
Having a lower socioeconomic status can also affect access to healthy foods. Eating ultra-processed foods has been associated with increased risk for cardiovascular disease and diabetes. There is now evidence that consuming these foods can also negatively affect some aspects of cognition. What do you think this means for society as we continue to eat these processed foods?
Dr Edelmayer: Continuing to identify strategies to reduce risk is going to be very important for our society. I think on a global level, there’s growing evidence that what we eat could potentially impact our brains as we age. We’re learning more about how eating heart-healthy, balanced diets that are low in processed foods and high in whole and nutritional foods like vegetables and fruits may actually be important for our brains. Not everyone has a choice about the nutritional foods that are available to them within their communities. As we continue to look at the evidence, it’s also going to be important for us to test whether addressing this particular factor reduces risk for cognitive decline or even dementia in the future.
Is there anything else that should be addressed under the umbrella of socioeconomic status and cognition?
Dr Edelmayer: I would add that a key theme that I’ve seen at our AAIC meeting this year is there needs to be more inclusion as we continue to do our research. Many studies are only looking at particular groups or populations. If we want the results and discoveries to benefit all, we need to continue to think about how trials are designed to make sure that we’re looking at each individual, group, and population to ensure beneficial results. At this time, a lot of research is still not diverse in terms of race, ethnicity, and gender. We’re moving in the right direction, but there’s a lot more work that still needs to be done to be sure that any results and discoveries are going to be generalizable for all our communities.
- Klee M, et al. Socioeconomic deprivation, genetics and risk of dementia. In: Proceedings from the Alzheimer’s Association International Conference; July 31-August 4, 2022; San Diego, CA. [Abstract] 66803.
- Longoria A, et al. Allostatic load and the influence of economic adversity and neighborhood disadvantage on cognitive function in a multiethnic cohort. In: Proceedings from the Alzheimer’s Association International Conference; July 31-August 4, 2022; San Diego, CA. [Abstract] 68217.
- Manly J, et al. Parental SES buffers the effect of plasma pTau181 on memory among non-Latinx White, Latinx, and non-Latinx Black middle-aged adults. In: Proceedings from the Alzheimer’s Association International Conference; July 31-August 4, 2022; San Diego, CA. [Abstract] 66616.
- Kezios K, et al. Low hourly wages in middle-age are associated with faster memory decline in older age: evidence from the Health and Retirement Study. In: Proceedings from the Alzheimer’s Association International Conference; July 31-August 4, 2022; San Diego, CA. [Abstract] 61298.
- Gonçalves N, et al. Consumption of ultra-processed foods and cognitive decline in the ELSA-Brasil Study: a prospective study. In: Proceedings from the Alzheimer’s Association International Conference; July 31-August 4, 2022; San Diego, CA. [Abstract] 63301.