Reference News, July 18 report: According to the Australian "The Conversation" website on July 4, for many years, scientists have believed that inflammation inevitably worsens with age and quietly contributes to the development of diseases such as heart disease, dementia, and diabetes. However, a new study on indigenous populations challenges this view, which may reshape our understanding of aging itself.

The report said that for decades, scientists have identified chronic low-level inflammation - called "inflammaging" - as one of the main drivers of age-related diseases. It can be understood as the immune system of the body being in a state of overactivation - constantly fighting non-existent "enemies," gradually wearing down various organs and systems. But inflammaging may ultimately not be a universal feature of aging, but rather a byproduct of modern lifestyles.

A study published in the journal "Nature Aging" compared inflammatory patterns among four distinct communities around the world. Two of these communities came from modern industrialized societies - elderly people living in Italy and Singapore. The other two were indigenous communities with more traditional lifestyles: the Tsimane people in the Amazon region of Bolivia and the Orang Asli people in the forests of Malaysia.

Researchers analyzed blood samples from more than 2,800 people, observing a series of inflammatory molecules (called cytokines). Their goal was to determine whether the pattern found in earlier studies - that certain signs of inflammation increase with age and are associated with disease - also appears in other parts of the world.

The results showed that the answer is both yes and no.

In participants from Italy and Singapore, researchers found a fairly consistent pattern of inflammaging. As people aged, levels of inflammatory markers such as C-reactive protein and tumor necrosis factor rose in tandem in the blood. Higher levels were associated with a greater risk of chronic diseases including kidney disease and heart disease.

However, in the Tsimane and Orang Asli communities, the pattern of inflammaging did not exist. The same inflammatory molecules did not continue to rise with age. They also showed no strong association with age-related diseases.

In fact, in the Tsimane people, who face high rates of infection from parasites and other pathogens, inflammatory levels were often high. Yet, this did not lead to the same level of chronic disease incidence as in industrialized nations.

Despite high levels of inflammatory markers, the Tsimane had very low rates of diseases such as heart disease, diabetes, and dementia.

These results raise important questions. One possibility is that inflammaging - at least as measured by these blood signals - is not a universal biological feature of aging. It is more likely to appear in societies characterized by high-calorie diets, low physical activity, and lower risk of infectious diseases.

In other words, chronic inflammation associated with aging and disease may not simply result from an unavoidable biological process, but rather from a mismatch between our ancient physiology and the modern environment.

The study shows that in communities with more traditional lifestyles (where people are more active, eat differently from modern society, and are more prone to infections), the way the immune system works may be different. In these groups, higher inflammatory levels may be a normal and healthy response to their environment, rather than a sign of aging in the body as it grows older.

Another possibility is that inflammaging may still occur in all humans, but in ways that differ and cannot be captured by measuring inflammatory molecules in the blood. It may occur at the cellular or tissue level, which is not visible in the blood tests used in this study.

If these findings are confirmed, they could have significant implications.

First, they would challenge how we diagnose and treat chronic inflammation during the aging process. Biomarkers used to define inflammaging in European or Asian populations may not apply to other environments, or even to all people within industrialized countries.

Second, they imply that lifestyle interventions aimed at reducing chronic inflammation, such as exercise, dietary changes, or drugs targeting specific inflammatory molecules, may have different effects in different populations. Methods that work for city dwellers may be unnecessary, or even ineffective, in populations that follow traditional lifestyles.

Finally, this study reminds us that much of our knowledge about human health and aging comes from research conducted in wealthy industrialized countries. It cannot be automatically assumed that findings from these groups apply worldwide.

This study provides a counterexample - what we thought was a universal truth about the biology of aging may actually be a local phenomenon shaped by our environment and lifestyle. (Translated by Zhu Jie)

Original article: https://www.toutiao.com/article/7528331369131409955/

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