Ray Kurzweil, 60 years of age, is convinced that in future it will be possible for man to live forever: “Applying today’s knowledge,” said Kurzweil in an interview with the Frankfurter Allgemeine Zeitung,“ […] even baby boomers like myself can still be biologically young and in a good shape ten or fifteen years from now where we can have Bridge Two which is being able to reprogram our biology through biotechnology. That will bring us to Bridge Three, when nanotechnology and nanobots inside the body will enable us to live indefinitely.”
Great progress in basic biological researchIn the industrialized countries over the last 150 years, growing material prosperity and medical progress have continuously lengthened the average life expectancy by about two to three years each decade. While in 1850 the average lifespan was forty years, today it already averages about eighty. Correspondingly, age-related illnesses such as cancer, cardiovascular diseases and senile dementia are on the increase and now constitute the main cause of death in developed countries. Nevertheless, experts assume that life expectancy will continue to rise.
Revolutionary developments in basic biological research, particularly in molecular biology and regenerative medicine, give cause for this optimism. The progress in the biological sciences is quite comparable to that in information technology. In future, the results of new research will be able to defeat many diseases and further prolong the healthy human lifespan.
Goals of the biological sciences in the “postgenomic era”The general goal of the biological sciences is to acquire a detailed understanding of the workings and development of living beings, from molecular processes within cells and the organization of cells into organs to the whole organism and eco-system, and eventually to control all this in a targeted manner. A milestone on the long way was reached with the complete sequencing of human DNA by the international Human Genome Project at the turn of the millennium.
The sequencing catalogued about 20,000 genes whose precise function is still largely unknown. The challenge today, in what bioscientists call the “postgenomic era”, is to understand the regulation and interaction of the genes and their many products with each other and with environmental influences. These molecules form complex genetic networks, signal paths and metabolic pathways, comparable to the electric circuitry in a computer. Here molecular biology is still in its infancy, but the progress it is making today is considerable.
Life-prolonging therapiesAccording to biology, the life of an organism is determined fundamentally by the interactions between its genetic program on the one hand and the environment on the other. Disease and death are traced to damage to cell components such as DNA or proteins and to organs. A precise knowledge of the operation of the damaged components could enable us to manipulate and repair them.
For example, cancer: here one of the most important discoveries in recent years is that cancers are generated by mutations of a few key genes in important molecular signal paths which normally protect the organism against uncontrolled cell division. With the help of molecular biology, pharmacologists have discovered imatinib, a new agent that seeks out and attaches itself to a damaged gene product caused by certain form of leukemia and tumors and thus suppresses the pathological increase in cell division.
Nanotechnology and regenerative medicineBasic research is also already banking on nanotechnology. For instance, it has been demonstrated in the case of mice with pancreatic cancer that the injection of nano-particles filled with a chemotherapeutic medicine lead to a decrease in metastasis. The nano-particles target and dock at a protein that occurs particularly in aggressive tumors while sparing healthy tissue. These are only two examples of a vast amount of recent research results. In sum, it seems probable that in a few years many new forms of molecular therapy will become available. In twenty years, many previously fatal diseases like cancer could become curable or at least controllable.
Scientists also hope for progress in regenerative medicine. Regenerative medicine aims at regenerating damaged cells and organs. One possibility of repair is gene therapy: the insertion of genes in cells to compensate for genetic defects. Studies on the use of stem cells are also in full swing. Stem cells possess the fascinating faculty of being able to generate tissue either of all kinds (embryonal stem cells) or of a certain type (adult stem cells). This nourishes the hope that they could enable damaged organs to regenerate.
How old can we become?How long is the lifespan of an organism? For what length of time is it genetically programmed and for how long can it be potentially re-programmed? Though these questions are largely unanswered and the object of many competing theories, the basic research has already delivered interesting clues. For instance, we have known now for some time that the maximum lifespan of model organisms such as yeast, threadworms, fruit flies and mice, with which man is evolutionarily related and which share many of his genes, can be prolonged up to 50% by a reduced-calorie diet. The reason for this is that the production of energy from nutrients generates so-called “free radicals”, which can damage DNA and protein. The less food, the less cell damage, and the longer the life.
Sensational studies in recent years have been able to obtain the same life-prolonging effect by manipulating the activity of certain genes. Researchers discovered that these genes are components of molecular signal paths which regulate energy metabolism and also activate proteins that repair damage to DNA. Subsequent studies observed that the naturally occurring agent resveratrol, high concentrations of which are also contained in red wine, bonds with the repair-proteins and activates them. In the model organisms, its application led to the same dramatic prolongation of lifespan as did fasting.
Society and ethical questionsWhether or not Ray Kurzweil’s vision of eternal life will ever be fulfilled cannot be answered from our present standpoint. But it seems fairly probable that in future man will live appreciably longer – and that while in the best of health. This of course raises social and ethical questions of tremendous importance. Up to now, the fight against disease and death has been looked upon as something good. Will that still be so when someday a human being can live for 150 years or longer? And what does all this signify for the co-existence of the generations?
Peter Gruss (ed.): Die Zukunft des Alterns (München: Verlag C.H. Beck, 2007), 334 pages.
Dr. rer. nat., is a nanophysicist and bioinformatics scientist, and works at the Max Planck Institute for Molecular Genetics in Berlin. His research concerns the molecular causes of cancer, obesity, ageing and the differentiation of adult stem cells.
Translation: Jonathan Uhlaner
Copyright: Goethe-Institut e.V., Online-Redaktion
Any questions about this article? Please write to us!