Can you lengthen or restore your telomeres?
Healthy adult body cells cannot lengthen their own telomeres, and no proven safe way to do so from the outside yet exists. Be sceptical of supplements or therapies that promise otherwise.
Telomeres are the protective caps at the ends of your chromosomes. They shorten with every cell division. Once they reach a critical length, the cell stops dividing or enters a state of crisis: chromosomes can fuse together and the genetic information becomes unstable. This is a fundamental part of how cells age.
The body has its own mechanism for replenishing telomeres: an enzyme that synthesises telomere DNA. This enzyme is active in germ cells and early embryos, and helps, together with other mechanisms, to ensure that a new life starts 'fresh' with long telomeres. In ordinary adult body cells, however, this enzyme is barely active. Telomere shortening is therefore largely irreversible in those cells.
Cancer cells show what happens when that enzyme does become active in normal body cells: they can keep dividing without limit. That is precisely why telomere lengthening as a therapy is so complicated. Activating this enzyme in healthy cells could, in theory, also drive cancer cells or promote the development of cancer. This tension makes targeted treatments particularly difficult.
Roughly 10 to 15 percent of cancer cells use a different mechanism: they copy stretches of telomere DNA from the ends of other chromosomes. This leads to very long and irregular telomeres. This too is exclusively a cancer mechanism, not something that can be 'switched on' for rejuvenation.
At present, there are no proven treatments that safely and effectively lengthen telomeres in healthy people. Researchers describe telomere biology as a promising but complex therapeutic field. Supplements or lifestyle interventions that claim to lengthen your telomeres have not been examined in the studies on which this answer is based.
This answer draws on several review articles by groups of molecular biologists and cell researchers. The basic biology of telomeres and the enzyme that replenishes them is well established and considered causally proven. Therapeutic applications in humans have not yet been demonstrated; the researchers themselves describe this field as promising but complex, with no concrete clinically proven treatments.
What does telomerase do to the length of your telomeres?
Telomerase keeps telomeres intact for longer by compensating for shortening during cell division, but in most body cells the enzyme is barely active, causing telomeres to shrink over time.
Why do your telomeres get shorter as you age?
Telomeres shorten because the copying process during cell division cannot fully reproduce the ends of chromosomes, and the repair enzyme telomerase is switched off in adult body cells. Stress and oxidative damage can accelerate that process further, but the fundamental mechanism is unavoidable as long as cells divide.
How do telomeres protect your DNA?
Telomeres protect your chromosome ends through a system of proteins that simultaneously prevents false alarms and harmful fusions. If that system fails due to inherited defects, you can develop serious ageing-related diseases.
Can clearing out "zombie cells" slow down ageing?
Animal research convincingly shows that clearing zombie cells slows ageing. That effect has not yet been systematically demonstrated in people, and exercise already produces comparable biological effects at the cellular level.
What are telomeres and can I keep them longer?
A healthy lifestyle, regular exercise, stress reduction and adequate vitamin D appear to slow telomere shortening, but anyone looking for a quick fix will not find one: the science is not there yet.
Can you lengthen your telomeres through lifestyle?
Lifestyle can probably slow telomere shortening, but the starting length of your telomeres is largely genetically determined and by far the strongest predictor of how quickly they shorten. Not smoking, exercising regularly and following a Mediterranean diet are the most well-supported steps you can take.