The Elixir of Immortality
How scientists are trying to stop the "gray tsunami" of old age
Brian Kennedy, one of the leading experts in the study of human aging, spoke about whether there is a limit to human life, and explained why the fight against aging is today the main task for all countries of the world.
Photo: Buck Institute for Research on Aging
Professor Kennedy has been studying various processes that cause the human body and cells to age for almost three decades, and is trying to figure out how to stop this process by experimenting on animals and volunteers.
Two years ago, his team managed to discover two hundred genes possibly related to aging by conducting experiments on yeast with partially human DNA. These experiments served as the basis for the first experimental therapies to slow aging, which will soon begin clinical trials on volunteers in the Kennedy Laboratory at the National University of Singapore.
Last week, he gave a public lecture at the conference "Phystechbiomed", organized by MIPT, in which he talked about what his laboratory has managed to achieve, how alcohol affects the rate of aging of the body and why the governments of Singapore and the United States put the fight against the aging of the population of the whole Earth, the "gray tsunami", on one of the first places among their national interests.
– Brian, in recent years, your colleagues have often argued about whether there is a limit to a person's life that cannot be crossed. Does it exist or not?
– These disputes have revived in recent years for the reason that recently colleagues conducted several studies on the life expectancy of the oldest people on Earth. They showed that the average life expectancy on the planet has continued to grow in recent years, but its maximum values have not changed.
I look at this problem from a slightly different angle, since I work mainly not with people, but with animals. Whatever organism we work with, in all cases we have managed to increase the maximum life expectancy. There is no reason to believe that this cannot be done for a person.
On the other hand, this question, in fact, is somewhat different: we do not yet know for what reasons the maximum life expectancy increased earlier, were these some natural factors or some actions of the person himself. In the future, when we start using life-prolonging medicines, I am sure that they will also work on the longest-lived people.
– Many of your colleagues in Russia believes that there is a genetic "aging program" that causes animals to become decrepit and give way to a new generation. Do you agree with them?
– Two different issues are raised here. On the one hand, the data that we have today indicate that there is no such program and that the body's decrepitude occurs by itself.
The reason for this is natural selection – its influence on how the human and animal bodies work weakens after they have already left offspring and stopped reproducing. From the point of view of evolution, human life ends at the age of 30-40, and this has been true for most of human history, since almost all of our ancestors rarely lived to this mark.
For this reason, those errors in DNA that affect our life after the end of this period were practically not corrected during our evolution, which began to interfere with humanity only in the last 200 years, after the advent of medicine and the beginning of a sharp increase in life expectancy. Chronic diseases have appeared, taking the lives of an increasing number of people.
On the other hand, even if there is no such program, it cannot be said that the impact on single genes or groups of genes cannot affect the rate of aging. Despite the fact that the aging of the body is largely a random process, some of its features are common to humans and many other animals, and this can be used.
For example, calorie restriction prolongs the life of many animals, not because it directly slows down aging, but because lack of energy "includes" sets of genes associated with stress and lack of food. These genes appeared in our DNA and in the genomes of animals not because they are associated with aging, but because they helped them survive in difficult situations. The same protection from stress, as it turned out, helps the body to resist aging better.
– If we talk about animals, today scientists are trying to find the key to aging by experimenting on a variety of creatures, starting with yeast and ending with naked diggers. Which of them will bring us closer to solving this riddle the fastest?
– In fact, there is no answer to this question, since each animal makes its own contribution to the study of aging. For example, yeast and fruit flies are completely different from humans, but their short life cycle allows us to quickly study the work of individual genes in their DNA. As it turned out, many of these genes associated with aging have their analogues in the DNA of mice and, possibly, humans.
On the other hand, really long-lived creatures, such as naked diggers, help us study other processes that are extremely difficult to catch or notice in experiments on yeast or flies. In general, we should conduct research on all model organisms, taking advantage of the differences in their vital activity.
– Have you managed to achieve new successes in the study of aging genes using the example of your yeast with human genes?
– We have been studying yeast for a very long time, and now we can say that these fungi played a key role in the study of aging, as they helped us find the SIRT2 and mTOR genes, the impact on which helped us noticeably prolong the life of mice and other animals.
Now we are trying to get a complete picture of aging – how not one, but all 230 genes that we discovered two years ago affect this process, and how they interact with each other. This is a very long process, but we hope that yeast will help us to fully describe for the first time what happens when the human body becomes decrepit.
– If you manage to slow down aging, won't it lead to the fact that the cells of the body of such an "immortal" person will eventually lose the ability to divide or become predisposed to the development of cancer?
– It seems to me that such a problem will not arise, since the rejuvenation of cells should also lead to the fact that they will retain their normal ability to divide. So far, our experiments show that all experimental methods of life extension not only increase the life span of animals, but also allow them to stay healthy much longer than usual.
This is the main goal of all my work – I care if I can make a person immortal, but at the same time infinitely sick. I would like people to stay healthy for as long as possible, and if they manage to live longer at the same time, it will be a pleasant, but an additional bonus.
– Relatively recently, your colleagues from California were able to rejuvenate mice by temporarily turning on genes related to the work of stem cells in their cells. Will such "extreme" forms of struggle with old age cause protests from politicians and the public and will they be possible to put them into practice in the foreseeable future?
– It seems to me that this approach and many other methods of rejuvenation need to be tested in experiments on volunteers, but most of them are not yet ready to work with a person. In addition to ethical reasons, there are a number of technical problems that make the results of tests on mice and other rodents extremely difficult to transfer to humans.
Already, there are drugs, as well as various diets and lifestyles that should greatly affect the rate of human aging. And if we can prove that these simple and relatively safe measures really prolong life, then, it seems to me, the public will be ready for bolder steps.
Of course, someone may not like manipulations with genes and the work of cells, but how, in fact, are cancer treatment and the fight against aging different? From the point of view of medicine, age and aging are the main risk factors in the development of malignant tumors and a number of chronic diseases, and therefore victory over aging will mean victory over them.
In fact, the cure for aging will also work as a means to prevent the development of cancer, heart disease and other health problems that today claim the lives of most elderly people. It is unlikely that anyone will have ethical claims against us if they understand this connection.
Moreover, the fight against aging will help us to solve or postpone the main problem of the future, the "gray tsunami", the real economic end of the world, generated by the fact that today there are fewer young people on Earth and more and more elderly people who need to pay a pension and who need to be cared for.
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02.10.2017