We blame tiredness, minor ailments or the marks of time on age, without really knowing what is happening inside. Research increasingly points to one actor at the heart of ageing: the mitochondrion, our cells' power plant.
Power plants that run out of breath
Mitochondria produce the energy of almost all our cells through a chain of proteins, the respiratory chain. A review published in October 2026 in the journal Mitochondrion takes stock of what goes wrong with age. The parts of this chain assemble less well, chemical modifications build up, and energy production becomes less efficient.
This slowdown first affects the organs that consume the most energy: the brain, the heart, the muscle. The authors link these defects to nine broad families of age-related diseases, from brain disorders to cancers, while recalling that this is a review of mechanisms, not a trial in humans.
DNA that leaks, inflammation that sets in
Mitochondria have their own small DNA. When they are damaged, fragments of this DNA escape into the cell. A review published in October 2026 in Biogerontology describes what follows: the cell mistakes this DNA for that of a microbe and triggers an alarm, through a defence pathway called cGAS-STING. This alarm lights a discreet but permanent inflammation.
Researchers have given this age-related background inflammation a name: "inflammaging". It is not a fever, rather a background noise that, year after year, wears down the tissues. The authors note that this pathway mainly sustains inflammation: on its own, it is not enough to trigger ageing.
Cells that no longer die but no longer work
With age, some cells stop dividing without disappearing: they are said to be senescent. They accumulate and keep sending inflammatory signals to neighbouring cells. The two reviews agree on this point: mitochondria in poor condition are both a cause and a marker of this senescence.
These works remain syntheses of mechanisms, often established in the laboratory or in animals. They offer no anti-ageing recipe. But they outline a clear target: taking care of your mitochondria means acting upstream of the inflammation of age.
What to remember
- With age, mitochondria produce energy less efficiently, especially in the brain, the heart and the muscle.
- Their DNA can leak and awaken a background inflammation, "inflammaging".
- Damaged mitochondria accompany senescent cells, which wear down the tissues around them.
- The evidence is mainly mechanistic: no anti-ageing recipe, but an increasingly clear biological target.
Sources
- Zhang X, Tao T, Liu W et al. Mitochondria and associated complexes as therapeutic targets in aging. Mitochondrion, 2026. https://doi.org/10.1016/j.mito.2026.102221
- Zhang Y, Zhu J, Cui L et al. Mechanistic reprogramming of the mtDNA-cGAS-STING axis in cellular senescence. Biogerontology, 2026. https://doi.org/10.1007/s10522-026-10515-z
