Proteins do much of the work inside our cells.
They help build tissues, carry signals, support the immune system and allow thousands of chemical reactions to happen every second.
But a protein works properly only if it has the right shape. If it is damaged or folded incorrectly, it may stop doing its job.
Healthy cells have systems that check protein quality. Some proteins are repaired, some are refolded and others are broken down and removed.
This continuous process of keeping proteins correctly shaped and working properly—and breaking them down when they become damaged—is called proteostasis.
As we age, these quality-control systems can become less effective. Damaged or incorrectly folded proteins may begin to build up inside cells. Scientists call this loss of proteostasis.
Why does this matter?
A damaged protein may fail to carry out its normal task. It may also stick to other proteins or place extra pressure on the cell’s cleaning systems.
This is especially important in long-lived cells, such as nerve cells, which cannot always be replaced easily.
The build-up of damaged proteins is seen in several conditions that affect the brain and nervous system, including some forms of dementia.
Protein maintenance also depends on other systems inside the cell.
Cells need energy to make, repair and remove proteins. They also need recycling mechanisms that can recognise what is damaged and decide what should be kept or destroyed.
If one part of this system becomes less efficient, the others have to work harder.
When damaged proteins build up, cells need more energy to remove them, and inflammation may increase. The idea should not be confused with popular “detox” claims.
The body does not clear damaged proteins through one drink, supplement or short programme. Protein maintenance is a continuous process that happens inside cells throughout life.
There is also no single routine test that can show how well proteostasis is working across the whole body.
For healthy ageing, the practical message is simple: cells need good conditions to maintain and repair themselves.
Regular physical activity, adequate sleep and balanced nutrition support many parts of normal cellular function. They cannot prevent every protein from becoming damaged, but they help create the conditions in which the body’s quality-control systems can keep working.
Healthy cells must do more than make new proteins.
They must also keep proteins correctly shaped, working properly and under control.
