Biomarkers of Aging: Understanding Inflammaging and Its Impact
Explore how chronic inflammation, known as inflammaging, accelerates aging and age-related diseases. Learn the role of gut microbiota and biomarkers in metabolic health.
As we age, the body undergoes a variety of changes, many of which converge on a single, significant process: inflammation. More specifically, a type of chronic, low-grade inflammation known as inflammaging plays a central role in driving the progression of age-related diseases. This inflammation is not the result of infection or injury, but rather a slow and steady activation of the innate immune system over time, influenced by several internal and external factors.
What Is Inflammaging?
Inflammaging refers to the persistent, sterile inflammation that develops as we age. It is a state of chronic inflammation without the presence of actual pathogens, and it contributes to the development of several age-related diseases like cardiovascular disease, diabetes, and neurodegenerative conditions. From an evolutionary standpoint, inflammaging is thought to be triggered by a variety of stimuli, including:
- Pathogens (non-self),
- Endogenous cell debris and misplaced molecules (self),
- Nutrients and gut microbiota (quasi-self).
Our body's immune system relies on a small number of receptors that can recognize these signals. Over time, their repeated activation leads to persistent inflammation, which becomes damaging in later years.
Inflammaging and Metaflammation: Two Sides of the Same Coin
Interestingly, inflammaging shares many mechanistic pathways with metaflammation, a term used to describe the chronic inflammation that arises from nutrient excess or overnutrition. Metaflammation is commonly seen in metabolic diseases like obesity, type 2 diabetes, and fatty liver disease, and its presence can accelerate the aging process.
Both inflammaging and metaflammation involve the activation of the same immune pathways, further fueling inflammation in the body. The excess nutrients from a poor diet create metabolic stress, which compounds the effects of aging and increases vulnerability to chronic disease.
The Role of the Gut Microbiota
One of the key drivers of both inflammaging and metaflammation is the gut microbiota. The trillions of microorganisms residing in our digestive tract not only help us process nutrients, but they also have a profound influence on inflammation and immune function.
As we age, changes in the gut microbiota can lead to an increased release of inflammatory products, which contribute to both chronic inflammation and circadian rhythm disruptions. This, in turn, affects other organs and systems, further perpetuating the cycle of inflammaging.
Aging and Chronic Disease: A Vicious Cycle
Chronic diseases don’t just develop as a result of aging—they also accelerate the aging process. Diseases like diabetes, heart disease, and neurodegenerative conditions fuel inflammatory processes in the body, contributing to what can be considered accelerated aging. The longer inflammation persists, the more it contributes to both disease progression and the general decline in bodily function associated with aging.
New Biomarkers: Measuring Biological Age
Understanding the distinction between biological and chronological age is crucial in managing the health impacts of inflammaging. Chronological age refers to the number of years a person has lived, but biological age takes into account the health of an individual's cells and tissues. As chronic inflammation accelerates aging, scientists are developing new ways to measure biological age using biomarkers such as:
- DNA methylation,
- Glycomics,
- Metabolomics,
- Lipidomics.
These biomarkers offer insights into how metabolic diseases, like obesity and diabetes, influence biological aging and may offer new avenues for targeted treatments.
Conclusion
Inflammaging and metaflammation represent a significant convergence of aging, nutrition, and immune response. As more research emerges, it's clear that understanding these processes and how they interact with the gut microbiota and chronic disease can provide new strategies for managing aging and extending healthspan.
Sources
- Franceschi, C., Garagnani, P., Parini, P. et al. Inflammaging: a new immune–metabolic viewpoint for age-related diseases. Nat Rev Endocrinol 14, 576–590 (2018). https://doi.org/10.1038/s41574-018-0059-4
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