Mitochondria
Organelles found in almost every cell, nicknamed "powerhouses" because they produce ATP (cellular energy), with a central role in metabolism and ageing.
Mitochondria convert nutrients (glucose, fatty acids) and oxygen into ATP, the universal “energy currency” of cells. A muscle or heart cell can contain thousands of them; an egg cell, hundreds of thousands.
An original angle (bacterial origin and maternal DNA): mitochondria have an extraordinary history. They are probably former bacteria “swallowed” by our ancestral cells about 1.5 billion years ago, which became symbiotic (the endosymbiotic theory). The evidence: they have their own DNA, distinct from that of the nucleus.
This mitochondrial DNA is passed on exclusively by the mother (the sperm’s mitochondria are destroyed). That is why maternal lines can be traced over millennia through mitochondrial DNA (“mitochondrial Eve”).
Mitochondria, health and ageing:
- Their dysfunction is linked to ageing, chronic fatigue, and metabolic and neurodegenerative diseases
- Exercise is the most powerful stimulus for creating new mitochondria (mitochondrial biogenesis) and improving their quality
- Cold, fasting and certain nutrients (CoQ10, polyphenols such as urolithin A) support their function
- Mitophagy (recycling of worn-out mitochondria) is crucial: urolithin A (produced when the microbiota transforms pomegranate polyphenols) stimulates it
Mitochondria therefore link diet, exercise, the microbiota and ageing in one coherent network. Looking after them is the basis of vitality.