In the 1970s, the life expectancy of Spaniards exceeded 72 years. Four decades later, it stands at 83, even after weathering a global pandemic that has left tens of thousands dead, most of them elderly. However, many of our elders who lived almost the entire 20th century have also managed to reach the current moment: currently in Spain almost 20,000 people are 100 years old or older, a figure that has increased by more than 1 600 men and women. women just last year. If we extrapolate this progression, and taking into account the fact that medical advances are growing exponentially, will we easily reach 120 years of life in a relatively short period of time?

This was the premise of the debate organized by ABC between the biochemist and director of the National Cancer Research Center (CNIO), María Blasco, and the paleonthropologist and co-director of Atapuerca Juan Luis Arsuaga. Both, under the chairmanship of science journalist José Manuel Nieves, discussed the keys to the past, present and future of a process that affects all living beings on the planet, but which man tries to delay as much as possible .

“Most diseases find their origin in cellular aging. Understanding it would help us to stop it, just as it happens with infections where we know the germ that causes it,” said Blasco opening the presentation, sponsored by the Oesía Group, Novartis and Siemens Healthineers and with the participation of la Xunta de Galicia. The researcher knows very well what she is talking about: her career is centered on the study of telomeres, the tips of chromosomes which “wear out” with age. It is a bit like the plasticized tips of sneaker laces: Over time, they shorten and fray, losing their shape. Something similar happens with our DNA: as genetic material replicates, telomeres become smaller and smaller. When they reach a minimum length, the cells interrupt their cell cycle and stop regenerating tissues, thus producing the aging of the cells and, consequently, the aging of the entire organism.

The “miraculous” enzyme

However, in 1985, Australian biochemist Elizabeth Blackburn discovered a “miraculous” enzyme: telomerase. This promotes the formation of telomeres, so if their production could be controlled we could, in theory, delay cellular aging. In fact, there is a type of cell that already uses this mechanism to its advantage: cancer cells. “These replicate indefinitely, maintaining telomeres, albeit aberrantly; but they become a kind of ‘amortal’ cells which, although they can be destroyed, constantly replicate themselves”, explained Blasco on this subject, who however clarified that this is not the only factor that intervenes in aging “For example, mice, which live three years, have longer telomeres than humans, but they only live three years and we are already reaching eighty. This means that epigenetics is more important than genes .

Epigenetics encompasses all factors that do not modify our DNA sequence, but rather modify its gene expression. In this part the factor of age and the passage of time intervenes; but also environmental elements such as diet, physical exercise, the medications we take throughout our lives or the chemical substances to which we are subjected. For example, we know that being in continuous contact with pesticides can “activate” the Parkinson’s disease gene that we had not a priori activated and cause its manifestation. Or, conversely, sport can produce epigenetic changes that improve the function of genes related to metabolism, inflammation and cardiovascular health.

The meaning of dying

However, death is a fact. And Arsuaga recalled that, although human societies have always dreamed of delaying it and even avoiding it forever, perishing makes sense from an evolutionary point of view: “The specimen that dies gives way to more young people who will perpetuate the species,” he stressed. . . And although Arsuaga himself wishes the end of our lives were timed (“I wish death had a clock so we could hack it”; everything would be much easier,” he lamented), the truth is that due to external factors and internally, it happens to each of us at a different time.

It is not the same with other processes. “For example, when mammals teethe, which happens in childhood. But why does this happen to us around six years old and to the macaques, who are our parents, does it happen around one and a half years old?” he asked, emphasizing that we need to know more about the factors that unite us and, above all, all, they separate us from the rest of the animals in order to stop aging.

Because the past surely holds the keys to our future and how to “extend” it: “As a species, we have extended not only life, but also childhood. Our brains have tripled in size. Can we continue to make changes? Of course: evolution has already shown us that,” he said.

However, it is necessary to distinguish the notions of life expectancy and biological limit, as Blasco points out: the first is relatively easy to transform, as demonstrated by the data presented at the beginning of this text. The second, for the moment, is established by the Frenchwoman Jeanne Calment, born in 1975 and died in 1997, living exactly 122 years and 164 days, the record among Homo sapiens. “But it is not only about extending life, but also about being healthy longer,” added Blasco, who explained that although it is more complicated to extend the biological limit than the life expectancy, experiments have already been carried out with yeasts, flies, worms and mice which have even almost doubled this vital boundary, thus avoiding aging longer.

Nor do we need to resort to pioneering experiments to see that science and technology come to our aid. “My friends, without these advances, would now be disabled or blind, because most of them have undergone hip or cataract surgery,” Arsuaga emphasized. The paleoanthropologist told the story of a well-known automobile brand in which the boss asked his engineers how long the strongest part would last. “That’s it, and it lasts almost forever,” the workers replied. “Well, I don’t want it,” the manager snapped, saying that if the rest of the car wasn’t going to last that long, it wasn’t worth making it that durable. “The same thing happens with nature: over the years, our lens deteriorates and we develop cataracts. When, we are supposed to be dead. Our “pieces” have a guarantee as long as we are young, but when we get old they start to decompose,” compared the co-director of Atapuerca.

However, there are things we can do to age healthier, since our sentence is not, at least entirely, written in our genes: studies have shown the importance of a balanced diet, physical exercise and avoid bad habits. What does not exist, at least for now, is a “miracle” cure: “There are many products on offer that claim to be able to do this or that thing; and of course, testing begins with innovative treatments. But the truth is that at present there is no completely effective drug to delay cellular aging,” said Blasco, who nevertheless recalled the study from Columbia University (New York) published in June last in the journal “Science”, in which it was shown that taurine promotes healthy aging, improves strength, coordination or memory, in addition to attenuating cellular senescence, DNA damage and “chronic inflammation. At least in mice and macaques. “Yes, a lot of progress is being made. But, at present, there is not a single disease linked to aging that can be cured. is the truth”.