its relationship with aging and longevity

Getting older seems like a simple process. until one tries to explain what really happens inside the body. We get older, we lose part of our recovery capacity and some tissues begin to function less effectively. That is what is visible. At the cellular scale, this story becomes considerably more interesting and even more complex.

What are telomeres and where are they in DNA?

In recent times, The telomere has been one of the elements that has received the most attention. It is located at the ends of chromosomes, long-lasting DNA structures where genetic information is stored. Telomeres are made up of repetitive DNA sequences and play the role of a protection zone.

They do not encode a specific protein nor do they determine, on their own, whether we will have eyes of one color or another. His work is less striking, but fundamental: protect chromosome ends.

The classic comparison is that of the small plastic ends on shoelaces. It may seem too simple, although it works quite well. When that plastic disappears, the cord begins to fray and handling becomes difficult. Without adequate telomeres, the ends of chromosomes can also deteriorate, fuse together, or be mistaken by the cell for fragments of broken DNA.

The detail that made these structures the protagonists of longevity research is another: their length changes over time. And it doesn’t usually do it in our favor.

How telomeres shorten with each cell division

Cells divide constantly. For a cell to divide, it needs to copy its DNA almost completely and deliver a copy to each daughter cell.

The system is extraordinarily effective, but it has a known limitation. The enzymes responsible for copying DNA cannot perfectly replicate the end of linear chromosomes. There is always a small area left uncopied. That technical problem results in a gradual loss of telomeric DNA.

Simply put: each cell division can shorten telomeres slightly. A single division hardly matters, nor does ten. Telomeres have thousands of repetitions that function as a security reserve. The conflict appears after many cycles, when that protection reaches a critical length. Then the cell detects a signal similar to that which would produce a damage to the DNA.

One of their possible responses is to stop dividing. This is what we know as cellular senescence.

People of the same age can have different telomere lengths. Genetics plays a role, but so does disease history, exposure to oxidative stress, and numerous environmental factors. Even within the same person, telomeres are not exactly the same length in all tissues.

The relationship between short telomeres and aging diseases

Research finds association between short telomeres and aging diseases. Short telomeres do not mean inevitable disease.

In many cases, their shorter length may reflect years of cellular wear and tear. Persistent inflammation and oxidative stress They damage cellular structures and force certain tissues to renew themselves more frequently. More divisions potentially mean greater consumption of the telomeric reserve.

The immune system allows us to observe well this process. When an infection appears, some defensive cells need to multiply quickly. It’s part of your job. After decades of exposure to viruses, bacteria, and other challenges, certain populations of immune cells have gone through numerous cycles of division. Their telomeres may be shorter and their response capacity lower.

These are rare situations, but they have served researchers as a kind of biological window to understand the consequences of poor telomere maintenance.

What habits lengthen or shorten telomeres according to science

We cannot choose the genes we inherit. Yes we can modify part of the environment in which our cells liveand this difference seems to have some influence on telomeres.

Tobacco is probably one of the clearest examples. Substances present in smoke They increase oxidative damage and maintain inflammatory processes that affect numerous tissues. Various studies have linked smoking with shorter telomere length.

Obesity and sedentary lifestyle They also appear associated with faster wear. There does not appear to be a single responsible mechanism. Chronic low-grade inflammation, metabolic alterations and increased oxidative stress play a role. The body functions as a connected system; Trying to isolate a single cause is often artificial.

Prolonged psychological stress has attracted particular interest. We are not talking about being late for work or having a bad week, but about continuous stress.

Telomerase: the enzyme that could slow aging

The cell has a tool capable of add new sequences to telomeres. It’s telomerase, an enzyme that uses an RNA template to rebuild some of the lost telomeric DNA.

Its activity is high in germ cells and in certain stem cells. It makes sense. They are cells that need to divide many times and retain their capacity for renewal for longer.

What relationship does it have with cancer? Many tumor cells manage to reactivate telomeresto. A normal cell ends up finding limits to continue dividing; a cancer cell needs to get around them. Maintaining your telomeres allows you to continue multiplying for much longer.

That is the great dilemma of research. Boosting telomerase can increase the regenerative capacity of certain tissues; however, this must be done carefully to avoid potentially tumor cells.