Ageing is not one process. Researchers describe several changes that build up in cells over time, and together they explain why tissues gradually repair themselves more slowly.
- Shortening chromosome caps. The protective ends of chromosomes get shorter each time a cell divides, which eventually limits further division.
- Less efficient energy production. Mitochondria, the parts of the cell that produce energy, gradually work less efficiently.
- Worn-out cells that linger. Some cells stop dividing but are not cleared away, and they release substances that irritate surrounding tissue.
- Low-level inflammation. A mild, persistent inflammatory state becomes more common with age.
- Slower protein housekeeping. Cells become less effective at repairing and recycling damaged proteins.
How signalling changes with age
The body coordinates repair and maintenance with chemical messengers, many of which are peptides, meaning short chains of amino acids. With age, the output of some of these messengers falls and tissues respond to them less readily. This is a large part of why repair slows down.
Where amino acids come in
- Maintaining muscle. Muscle mass tends to decline from mid-adulthood, commonly estimated at 3 to 8 percent per decade after the age of 30.
- Higher protein needs. Older adults respond less strongly to a given amount of protein, so expert groups often suggest a higher intake for them, around 1.0 to 1.2 grams per kilogram of body weight per day.
- Tissue upkeep. Skin, bone, connective tissue and the immune system all depend on a steady supply of amino acids.
What influences healthy ageing
- Regular physical activity, especially resistance training
- Enough protein and a varied diet
- Sleep
- Not smoking and limiting sun damage
- Staying socially and mentally active
This article is for general educational purposes only and is not medical advice.
Frequently asked questions
What causes ageing?
A combination of gradual changes in cells, including shorter chromosome caps, less efficient energy production, lingering worn-out cells and slower repair.
What are mitochondria?
They are the structures inside cells that turn nutrients into usable energy. Their efficiency tends to decline with age.
Why does protein matter more with age?
Muscle is lost gradually over the decades and older bodies respond less strongly to protein, so adequate intake becomes more important.
Can lifestyle really affect ageing?
Yes. Activity, nutrition, sleep and avoiding smoking are consistently linked with healthier ageing.
Is muscle loss with age inevitable?
Some decline is normal, but resistance exercise and adequate protein slow it considerably.
Is this medical advice?
No. This article is general educational information. Speak to a qualified healthcare professional about personal health decisions.