A series of overlapping crises has pushed many people living in high-income countries over the edge in recent years. A combination of rising inflation and weakened social services plus climbing longevity across Europe and the United States has meant that many adults are perpetually struggling to make ends meet. A record number of households in the United Kingdom, for example, are reporting financial adversity. This could be very bad news for public health.

A massive new study led by researchers at University College London (UCL) suggests that people who experience either persistent money struggles or persistent low income in early and middle adulthood may face worse cognitive performance at the age of 53, cognitive decline from ages 53 to 69, and worse brain health from ages 69 to 71.

The study, published in the journal Innovation in Aging, looked at data from 2,759 people in the U.K. who turned 80 this year and have been followed since birth in 1946. A subset of the people followed in the study, known as the MRC National Survey of Health and Development, or the 1946 British cohort study, also sat for brain scans. These links between financial struggle and cognitive aging remained even after accounting for factors that might have skewed the results such as childhood cognition, education level, and childhood disadvantage.

I spoke with corresponding author and UCL data scientist Jacques Wels about how financial hardship actually ages the brain, how the findings fit into the larger story about how society shapes our health, and how much control we have over our cognitive aging.

What inspired you to do this study now?

The department where I work is dedicated to aging research as it relates to a dataset called the National Survey of Health and Development, which for decades has tracked people born during a single week in 1946. This cohort turns 80 years old this year. It’s the oldest cohort in the U.K.

This group can offer a lot of information on aging, which is something that other large cohort studies don’t have because they include mostly younger participants. It’s one of the only studies where we can not only track people over their lifetimes, but also have brain scans, which allows us to look at the relationship between aging and brain health. In fact, we really want to thank this cohort of people. Without them, we wouldn’t be able to do this important research.

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You found that people with persistent financial hardship are more likely to have cognitive decline in their 50s and worse brain health as they progress into their 70s and beyond. What do you think is going on here?

One important thing is that most studies on cognitive decline focus on individual behaviors, whether you’re drinking, smoking, or behaving in other unhealthy or healthy ways. Alternatively, they focus on genes, like the APOE gene, that help to explain cognitive decline. We thought it would be important to go beyond these behavioral explanations or genetic explanations and look at what society does to your brain. What society does is to generate potential inequalities over a person’s lifetime, and most of the time these are economic inequalities.

Based on what you found in the study, is there something about the stress induced by persistent financial struggles that is different from other kinds of stress?

There’s a lot of debate about oxidative stress and whether stress can have an impact on inflammation, for example, but we didn’t address that. What we addressed is the accumulation of poverty over the lifespan, and what we observed at first after 50 and 60 years old in terms of cognitive decline, was a strong and statistically significant association. Now on the mechanisms, we can make assumptions. The first assumption is the one you mentioned: stress. The second one is cognitive load. When you’re really worried, you don’t have much time to sit on a bench and play chess with a friend. What you can think about with your brain isn’t the same when you struggle versus when you don’t struggle.

Are you saying that thinking about playing chess is better for your brain than worrying about money?

Yeah, that fits within the behavioral pattern, you know? There are even some studies that say that doing crosswords, and similar kinds of games, is good for brain development. If all of your time is spent worrying about money, you don’t have time to think about things that are fun. And thinking about fun is good for your brain.

Do you have a sense of where financial adversity would rank in the overall picture of risk factors for cognitive decline, like diet, exercise, and social isolation?

I don’t think we could rank them, no. We would need the proper statistical techniques. Don’t forget also that addressing these different variables over the lifespan is really difficult using this kind of study.

What we were able to do, though, is to look at childhood adversities. There are a few studies that show that what happens in your childhood explains what happens in terms of cognitive decline after 50. What we show in this study is that actually, this accumulation of poverty over the lifespan and its impact on brain health is independent of childhood adversity. So we go beyond the framework of childhood adversities, which is an important finding. It means that even if it was bad during your childhood, there’s still a possibility that if you have a chance to do better in life, your brain will not be affected as much.

But distinguishing between the different variables you mentioned, social isolation and loneliness, would be fascinating. That’s not something we did, so I wouldn’t be able to rank them, but I can say that the effect of persistent financial hardship is quite strong.

The cohort you were studying were all born in 1946 and lived through different economic conditions than people alive today. To what extent do you think the patterns would hold for, you know, Gen X or millennials?

It’s very likely that the pattern will hold, but the way this pattern spreads over the population might be different. In this cohort, most of the effects are observed among men and not so much among women, which is interesting. But we need to remember that it was really a male-dominated society back then, where the men were working more than the women.

In younger generations, men tend to be healthier, while women tend to be less healthy than they used to be. As a result, in these younger generations, we might actually observe a relationship that’s a bit stronger between financial hardship and cognitive decline among females and probably a bit weaker amongst males. But people who are younger than 50 aren’t old enough yet to see cognitive decline. We would see that in the near future.

Similarly, your study sample is all British and white and skews a bit healthier. Do you think that the findings for the U.S. or the global south would look significantly different?

I need to be very cautious here. My first answer is, I don’t know. My second answer is, it’s not so much about the brain measurements. That isn’t a problem and could be replicated across countries. But the experiences of poverty are going to be quite different, and the accumulation of financial issues over the life course might also be different in other kinds of contexts. In the case of the U.S., it might be a bit worse in terms of income inequalities compared to the U.K. Whether this accumulates over the lifespan, I’m not sure. I tend to think it does, so I’d say that maybe the link between persistent financial hardship and cognitive aging will be stronger in the U.S. But that’s a hypothesis. U.S. researchers should do the same study we did and tell us what they think.

On the global south, it’s a very important question, but it depends which country we’re talking about. It depends on the level of inequalities. It depends on employment regulations as well, because employment is a main driver of financial stability over the lifespan.

Yes, I imagine so many factors could play into this lifespan picture, including the way families are structured, the way social support works.

The potential role of the welfare state is something we didn’t address here. I’m not saying the welfare state is the answer to everything, but it definitely plays a role.

You pointed out something very interesting, which is that this cohort, although it’s a great cohort, is very white dominated. We don’t have information about ethnicity because the number of non-white people born in the U.K. in 1946 was small. But it’s a multidimensional process where low household incomes are associated with ethnicity a lot in some countries. Understanding how this accumulates would be interesting, but it’s too early to tell.

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You conclude that supporting financially vulnerable adults could potentially help prevent dementia. What kind of support do you think would be most successful?

It’s an interesting question. The study shows an association between long-term poverty and brain decline. So what is the answer? We need to tackle long-term poverty or at least provide more security to people. And then it’s about what kind of society we want to live in. I’m not the first one to say that. When you provide more security to people, they tend to be healthier, and they tend to live longer, and they tend to have fewer health issues, and they tend to cost less to society.

But one important thing is to understand the pathways better. You mentioned social isolation. We know that financial deprivation and poverty are linked to social isolation, and social isolation is linked to cognitive decline. So we would like to better understand how these different variables interact and accumulate over the lifespan, and understand the mechanism for how financial instability explains brain health. We need to understand that to act because just saying that we need to provide more security isn’t a good answer in terms of public policy. We also need to understand the mechanism.

How does this study fit into the broader conversation about social determinants of health?

The definition of social determinants of health depends on whom you talk to, but it’s basically the idea that it’s not only the behaviors and the genes, but it’s also the society that shapes your health. The value of this specific study is to establish a structural association between what you observe in the lab and something that happens later. The weakness of this study, to be absolutely transparent, is that we can’t explain why we observe those relationships. But this study is one of the first to establish a relationship that seems to be causal between financial hardship and cognitive decline. It was important to establish it. The next steps will be to try to explain why the relationship works the way it does.

Personally, I believe we need to be more critical of the social determinants of health framework. Yes, poverty is linked to poor health. We know that. But why? How? The point of the social determinants of health framework is to focus on the determinants. A determinant is something that determines, so it’s a deterministic approach, an approach from the 1950s. That’s what social science tried to avoid for more than 40 years.

My problem with the social determinants of health is that we treat people as subjects. They are subjects, and they are victims. They aren’t agents of their own destiny. Of course, we’re all both. We’re both subjects and agents. My question is, to what extent do people actually have something to say and to what extent can they contribute to changing society in one way or another?

We never pay attention to what actually happens within the workplace, for example, but the kind of work you do, the kind of employment contract you have, even how unions function, have a big impact on your health. A very bad paper on unions was published in the United States in 2020, with a weak methodology, but in general, unions are something that people never pay attention to. It’s really not “lefty,” what I’m saying, because unions could have a negative impact, and they do in some countries and for some specific groups. But we need to understand better the mechanisms at work and move away from a deterministic approach.

Lead image: Hyejin Kang / Adobe Stock