Eat less and live more?

A classic biology experiment is one in which two groups of laboratory mice are selected. The first is given plenty of food while the second is rationed almost to starvation but without any real lack of nutrients. The results are almost always the same: Well-fed mice die much earlier than poorly-fed mice.

This phenomenon is explained by the fact that excess food can cause diseases such as diabetes or coronary type that take a fatal toll on the gluttonous individual. Obesity is also a risk factor for getting cancer. However, these simple experiments could not explain why some well-fed individuals lived much longer than expected and why other mice on a Spartan diet died earlier than expected.

It was long ago discovered that the longevity of an individual was closely related to the way in which cells divided. It is clear that individuals are aging and that by natural law when we have already served a good number of years, we die. That does not mean that we all die the same way. Some people are genetically programmed to live many more years than the rest of the people while others age much worse, not only internally, but at the cellular level.

Our body is made up of cells that divide to replace others that have already completed a life cycle. Some, like neuronal cells, do not and therefore when we lose some of them it is an irremediable loss.

The copy of each cell is supposed to be an identical copy of its "mother" but in reality it is not. With each division, part of the genetic code is lost and in the end the resulting cell is unviable and dies. It is what we call aging. To establish a simple parallelism it is as if we made a photocopy of a photocopy of a document and so on. In the end it would turn out that we would be unable to read the text it contained and therefore would be worthless. Other times, copying errors can generate genetic errors that, if not corrected by the corresponding genes, could lead to cancer diseases.

Telomeres are protectors of the chromosomes that prevent them from dividing if they are going to form new defective cells. The longer the telomeres, the less likely a copy failure will occur. Telomere length is inherited from our parents. So if our parents lived many years, it is most likely that our telomeres are also long and unless we have a fatal accident, our lives will be as long or longer than theirs.

Although the telomeres are long they also suffer wear and tear, so the oldest individuals will show signs of senescence does not matter how long their telomeres are,  although probably do so later than other individuals with short telomeres.

Is there a way to change telomere length? Yes, through the telomerase enzyme discovered in 1985 by Elizabeth Blackburn and Carol Greider. The discovery of this enzyme opened a whole field to prevent the natural aging of cells and more than one rubbed their hands thinking about its pharmaceutical possibilities. But there is a catch: if we inject telomerase into an individual, the possibility of developing cancer also increases. Cancer cells are immortal cells and their copies are perfect clones of themselves. If unfortunately some cell in the patient's body has genetic errors and is therefore pre-tumor, by injecting telomerase we are making it easier for said cell to become the germ of a cancer.

There are studies that indicate that in order to use telomerase effectively, it would be necessary to increase the defenses of the human body through the P53 gene, which is the one that destroys cancer cells endogenously. This has been achieved in mice but at the moment it is not clear how to do it with humans.

As research continues, several studies have argued that some foods can protect telomeres. For example, Turkish researchers indicated that propolis, a substance created by bees, is capable of influencing the enzyme telomerase. Other studies indicate that consuming folates from lentils, spinach, and whole grains have a similar effect. And the simplest thing, and something that the fat mice of the experiment already guessed to their misfortune, eating a lot of fruit and vegetables and low content of fats of animal origin also protects the telomeres.

Pills containing supposed protective elements have also started to appear, some of them based on traditional Chinese medicinal plants such as astragalus - in fact, a type of legume - and which are sold at astronomical prices. It is not demonstrated its effectiveness and they are certainly much more expensive than following a Mediterranean-type diet, which has similar effect.

For the time being we know what telomeres do but not how to alter them to make us to live more, eating or starving.