A remote tribe in the Amazon may hold the secret to aging with less inflammation

Lots of Americans experience more inflammation in their bodies as they get older. Researchers, in fact, have a term for it: inflammaging. But, new research from Arizona State University suggests it doesn’t have to be this way.

Scientists studied two communities in the Bolivian Amazon: the Tsimane and the Moseten. Their relative levels of inflammation as members of those communities got older can tell us something about aging in this country.

Jake Aronoff is a post-doctoral researcher at ASU, where he studies immune function and aging.

Full conversation

MARK BRODIE: Jake, let’s start with these two communities you studied. What about these two groups of people made them the right folks to be comparing against each other for this research?

JAKE ARONOFF: Yeah, so much of what we know about health and aging comes from studying people in the U.S. and in Europe. And we've experienced a great deal of lifestyle and environmental changes over the last few hundred years. So that can contribute to a lot of health problems and accelerated aging.

And so it's hard to understand sort of what human aging and human health and later life used to look like before we lived these modern lifestyles and experienced these modern environments.

BRODIE: So, in a sense, by looking at groups of people who have not sort of gone through the kind of modern changes that we have, it's almost like looking at a blank slate kind of thing?

ARONOFF: Yeah, yeah. So we can look at these populations. So the Tsimane, for example, they are forager-farmers in the Bolivian Amazon, so they have a great deal of physical activity. Just to give you an idea for comparison, studies in the U.S. find that Americans, on average, take about 5,000 steps per day. The Tsimane average a little bit over 15,000 steps per day.

They're much more physically active. Dietary studies have found that they're consuming minimal caloric excess, much lower saturated fats, processed sugar, processed food in general, compared to Americans. And so they can provide this model of: What does health and aging look like with basically optimal levels of physical activity and optimal diets?

BRODIE: So what you found is that in that population, they had less inflammation in their bodies as they got older. Is it too simple a conclusion that diet and exercise are the keys to reducing inflammation?

ARONOFF: I would say that is a large portion of it. So we focus on is this concept called inflammaging, the development of chronic inflammation in later life. And this is both a result of aging and disease, as well as a contributor to aging and disease. And so we wanted to answer the question of: Do we see the development of inflammaging in the Tsimane when you have high levels of physical activity and, and these relatively healthy diets?

And so what we did was we looked at a collection of pro-inflammatory immune measures — you can measure them in blood — to see if they increase with age. And we found very minimal increases with age, very minimal inflammaging, suggesting that inflammaging is minimal in this population. And so the reason we studied the Moseten was a potential critique of that finding is that these samples were measured in our lab with a particular assay technology.

And so maybe it's just there's some sort of measurement problem going on, and that's why we hardly found any evidence of inflammaging. And so then we looked at the Moseten. The Moseten are a neighboring population of the Tsimane. They used to be part of the Tsimane until a few hundred years ago. They split off with missionary contact.

And they've experienced more acculturation, more market integration. And so their lifestyles are kind of this in between the Tsimane and the U.S. And so then we predicted that with experiencing some level of lifestyle changes, a little bit less physical activity on average, a little more caloric excess and consumption of processed food on average, that we would see more pronounced inflammaging in the Moseten.

And so we have these samples from the two different populations. And we measured them at the same time in the same lab to rule out this potential measurement problem that might just be specific to our lab. And we found clearly more pronounced inflammaging in the Moseten.

Jake Aronoff

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Handout

BRODIE: So what does this tell you about, for us living in the U.S., like maybe what we should be doing to try to reduce inflammation and inflammaging?

ARONOFF: Yeah, so diet and exercise is a huge part of it. And that's something that kind of we already knew. And so this finding is really reiterating that if you can increase your physical activity, reduce your caloric excess, reduce consumption of processed foods, that can go a long way.

The other potential component that's going on is that the Tsimane are exposed to a lot of parasites, in particular hookworm. And that might be another piece of this puzzle that's protecting them from inflammaging. So infection with parasites can contribute to these effects on your immune system that can be anti-inflammatory.

BRODIE: Now I would imagine you're not going to advocate that here in the U.S. we all sort of get ourselves hookworm. So is there a way to maybe take the beneficial properties of them, that can help reduce inflammation, without all the negative effects that a hookworm or any worms can have on people, other parasites?

ARONOFF: Yeah, exactly. I'm not at all advocating people infect themselves with hookworms. Because the other component is that your immune system develops in early life in a particular way for a particular environment. And so a Tsimane person's immune system developed in a different way than someone in the U.S.

And so you introduce hookworms to those different immune systems, they might have different effects. And so because your immune system developed in the U.S. you might have a bad reaction to a hookworm infection.

BRODIE: It kind of sounds, what you're suggesting here, almost like a vaccine or like an allergy shot. Where like you give somebody a very small dose of something that they don't want as a way to build up the immune system. Is that sort of on the right track there?

ARONOFF: That is a possibility, yeah. I don't do that kind of research, but yeah, that's definitely a potential. The other factor is that parasites can alter your metabolic function. And so that could be another route through which the parasites influence immune function.

BRODIE: So do you see then that sort of the key takeaway from this research is, as you referenced, kind of confirming what we already knew. In the sense that healthy diet, good amount of exercise, like not being too sedentary, that kind of thing — as we age, that becomes more and more important to sort of stave off inflammation, inflammaging?

ARONOF: Yeah. So there's definitely a lot that we can do that's within our control to offset and slow the development of inflammaging.

BRODIE: What would you like to figure out next? What's the next sort of follow-on from this research that you think would be helpful to sort of continue our understanding of this?

ARONOFF: So, yeah, on the one hand, we're going to be looking at — so lifestyles are rapidly changing in that area. People are consuming more and more market-derived processed foods. Physical activity is going down a little bit over time.

And so to look at how these lifestyle changes are leading potentially to more pronounced inflammation. We're already seeing it in the Moseten and we might soon start to see that in the Tsimane.

And then the other part is to study these hookworm infections to see how they influence immune function and inflammaging.