What is Aging?

Aging is a summary term for a set of processes that -- over time -- contribute to the deterioration of health and ultimately death. Any process that contributes to age-related decline in performance, productivity and health is a component of the aging process that deserves our attention and intervention. Intervention in this context can include preventative strategies (such as diet, lifestyle and supplement use) along with the development and use of anti-aging medicines and medical technologies.

Aging can be thought of as a group of processes responsible for an increasing risk of frailty, disability, age-related degenerative diseases and ultimately death. This interpretation of aging matches the general definition of an aging system in reliability theory. An aging body -- like an aging automobile or household appliance -- is a system that experiences an increasing rate of failure with the passing of time. While failure in an automobile might be a faulty alternator, failure in the human body might be cancer, a degenerative disease such as Alzheimer's or liver failure.

Aging is a many-headed monster, and this causes problems for researchers. There are many types of age-related failures in the body (such as disabilities and degenerative conditions), often occurring simultaneously. Aging is not a simple process or progression. Rather it is a complex multidimensional phenomenon. Attempts to describe aging using one measure -- "biological age," "physiological age," or "real age" -- may be a misleading and even deceptive oversimplification.

More adequate scientific language to describe the aging phenomenon can be found in general system theory and reliability theory. Reliability theory predicts that a system may deteriorate with age even if it is built from elements that do not themselves age, but instead have constant failure rates. The key issue here is the overall redundancy of irreplaceable elements: ongoing failure of these elements is responsible for the aging phenomenon. Each small step in the deterioration of the system may seem to be random. If a system failure requires a sequence of several such small steps, then the system as a whole may have an aging behavior. To return to our examples, the front end assembly of an automobile will not fail until many small brackets and components have worn or broken. Similarly, many degenerative diseases or age-related conditions may be the end result of a chain of lesser failures and "breakages" in the human body.

Why is it important to make this very careful definition of aging? Because the significance of anti-aging medicine and technologies are often undermined by claims that these interventions are not proven to delay the process of aging itself. Instead they are said to simply delay or "cover-up" some particular manifestations of aging (e.g. disabilities, degenerative conditions and so forth).

In contrast to these pessimistic views, reliability theory tells us that there may be no specific underlying elementary "aging process." Instead aging may be largely a property of redundant systems as a whole. Each set of possible failures over time could be associated with a particular manifestations of aging. Therefore, we should not be discouraged by the partial success of each particular anti-aging intervention. Instead, how much better it is to appreciate that we have opportunities to oppose aging in so many different ways!

Thus, we can conclude that ongoing and valuable efforts to understand the early stages of age-related degenerative diseases should not be discarded as irrelevant to understanding "true biological aging". On the contrary, attempts to build a Berlin wall between biogerontology (the study of aging) and clinical medicine (such as the study of specific age-related degenerative diseases) are counterproductive. We should not forget that the main aging-related concerns for most people are deterioration of health and increased risk of death. The most important changes that occur with age are those that make older people sick.

How Aging is Viewed by the Scientific Community

Views on aging have changed dramatically. They have become more diverse and polarized in recent years. Just a decade ago, there was almost a consensus for considering aging to be an irreversible, universal, intrinsic process. Aging was often considered to be an immutable fundamental process; it was believed that little could be done about it.

As an example, it was believed that genetic mutations could only shorten lifespan, not increase it. Even if some mutants lived longer lives, the suggestion was that this came with the cost of a crippled life. Aging was considered to be a general form of gradual deterioration. Therefore, it was thought that any search for specific medicines and technologies to greatly increase lifespan would be futile and destined for failure. It was also believed that each living being has a specific maximum possible lifespan, which was set in stone for any given species.

In the 1980s, we first challenged the concept of species-specific maximum lifespan, argued that there is no fixed limit to longevity and suggested a reliability theory of aging. We brought forward the possibility that rates of mortality in later life can be reduced. The scientific debates were heated, and only after publication of our book in 1991 were our arguments taken seriously.

Now we are pleased to observe that the idea of a fixed upper limit to lifespan is rejected by many other researchers. There is a real fuss now over late-life reduction in mortality rates, which was described and explained in our book. The idea of the fundamental, immutable nature of aging is now challenged in professional scientific journals.

Aging studies are now in the state of paradigm shift. To be more direct, a scientific revolution is currently in progress. Controversies are inevitable in such transition periods and they do indeed exist today.

The most important current controversy is related to the evolutionary explanation of aging. Evolutionary biologists have always very generous in providing advice and guidance to gerontologists on how to take aging research "in directions that are likely to be fruitful." Surprisingly, this generous intellectual assistance proved to be extremely injurious for aging studies. Evolutionary theory was interpreted to indicate a search for life-extending single-gene mutations, medicine or technology was futile; destined to failure for fundamental evolutionary reasons. Researchers were convinced by the forceful evolutionary arguments of George Williams that:

"natural selection will always be in greatest opposition to the decline of the most senescence-prone system"

"Senescence should always be a generalized deterioration, and never due largely to changes in a single system. This conclusion banishes the 'fountain of youth' to the limbo of scientific impossibilities where other human aspirations, like the perpetual motion machine and Laplace's 'superman' have already been placed by other theoretical considerations. Such conclusions are always disappointing, but they have the desirable consequence of channeling research in directions that are likely to be fruitful." [Williams, G.C. (1957) Pleiotropy, natural selection and the evolution of senescence. Evolution 11, 398­411]

As a result of this triumphant evolutionary indoctrination, exciting research opportunities for life extension were squandered for half a century. Recently, however, the astonishing discovery of single-gene mutants with profoundly extended longevity was finally made, despite all discouraging predictions and warnings based on evolutionary arguments.

The recent discoveries of lifespan-extending mutations are spectacular. A single-gene mutation ("daf-2") more than doubles the lifespan of nematode worms, keeping them active, fully fertile (contrary to the predictions of some evolutionary theories), and with normal metabolic rates. Another single-gene mutation ("methuselah"), extends the average lifespan of fruitflies by about 35% and enhances resistance to various forms of stress, including starvation, high temperature, and toxic chemicals. Finally, a single-gene mutation was found in mice that extended lifespans by about 30% and increased their resistance to toxic chemicals.

Researchers involved in these studies came to the following conclusion:

"The field of ageing research has been completely transformed in the past decade. When single genes are changed, animals that should be old stay young. In humans, these mutants would be analogous to a ninety year old who looks and feels forty-five. On this basis we begin to think of ageing as a disease that can be cured, or at least postponed.The field of ageing is beginning to explode, because so many are so excited about the prospect of searching for -- and finding -- the causes of ageing, and maybe even the fountain of youth itself." [Guarente, L. and Kenyon, C. (2000) Genetic pathways that regulate ageing in model organisms. Nature 408, 255­262].

Now that single-gene life-extending mutations have been found, evolutionary biologists are presented with the task of reconciling these new discoveries with their theories. Gerontologists have an important lesson to learn from the damage caused by decades of misguided research, during which the search for major life-extending mutations, medicine and technology was equated to the construction of perpetual motion machine by evolutionary biologists.

All told, we really do live in an interesting time. New ideas about aging are here!

Intervening in the Aging Process

Human aging seems to have already altered dramatically in developed countries over the last 50 years, although these significant changes are not yet completely understood and appreciated both by the scientific community and the general public. This remarkable shift in the human aging schedule is largely overlooked by researchers and society. These historical changes have been slow and gradual, and we still do not understand exactly why and how they happened.

Why should we question and perhaps reconsider the conventional idea that human aging is immutable, set in stone?

The idea of immutable aging was supported in the past by demographic observations. Increases in human life expectancy were caused mainly by preventing deaths at young ages, while death rates at older ages (above age 80, for example) remained surprisingly stable. Demographers know this concept as "rectangularization of the survival curve." This very unwieldy term is used because the survival curve (showing the number of survivors as a function of age) has evolved throughout history towards a more rectangular shape. We were evolving into a society with a "compression of mortality" at older ages as more people survived to die closer to what was supposed to be the maximum possible human lifespan. This fixed biological limit to human longevity was believed to be determined by an immutable aging process.

In 1985, we challenged this conventional concept in our study "A new trend in human mortality decline: Derectangularization of the survival curve" published by the Journal of American Aging Association (Age, 1985, v. 8, p.93). Specifically, we discovered a new trend in mortality decline in developed countries like Sweden after the 1950s. There was a preferential and accelerating decrease in death rates among very old people. This paradoxical observation was later published in a more elaborate form in our book in 1991.

These findings challenged the existing scientific paradigm of immutable aging, and therefore they experienced several standard steps of scientific denial. Initially, these findings were simply ignored as if they did not exist. Doubts were cast over the data quality for mortality rates. Finally, when the unprecedented historical decline in mortality rates among the oldest members of the populace could no longer be ignored or disputed, it was claimed that these declines were not related to changes in human aging. Instead, it was claimed that these declines represented the undesired consequences of medical success in sustaining life, as more and more people are kept alive by artificial means in greatly debilitated and degraded conditions! This is simply not the case.

The key issue here is that not only did death rates decline preferentially among the oldest members of the populace, but their health status improved significantly over time as well. We observed that the time schedule for the manifestations of aging has been dramatically altered over the last 50 years in developed countries, and this fortunate trend seems to accelerate over time. In other words, the oldest people are living more healthily for longer.

If human aging is already altered, then the next question is "why has this happened?" I wish I knew the answer to this question, but there are some plausible working hypotheses to explore.

Aging retardation may be partially related to better nutrition among people who were fortunate enough to be born more recently. Early-life nutrition history is in fact a very serious matter. Even a trivial deficiency in micronutrients (i.e. essential vitamins, minerals and so forth) has the same devastating impact on DNA integrity as ionizing radiation, as found by Prof. Bruce Ames at Berkeley. People are terrified by the threat of radioactive pollution, yet they receive far more damage to their DNA from minor micronutrient deficiencies! There has been a remarkable improvement in vitamin consumption over the last century, and this might contribute to the observed postponement of aging manifestations. For example, the United States started adding vitamin D to milk and some other dairy products since the 1930s because of the high prevalence of rickets and osteomalacia in northern climates at that time. We know now that vitamin D supplementation, along with calcium in milk, also reduces the risk of bone fractures in elderly women through amelioration of osteoporosis.

Another possible contributing factor to remarkable postponing of aging may be the historical decline in disease in early life. Facts are accumulating to suggest that many diseases and disabilities of older age have their roots in previous exposures to infectious agents when younger. For example, chronic inflammation common to many infectious diseases is related to the later onset of arthritis, atherosclerosis, diabetes, Alzheimer's disease and cancer. Perhaps with improved sanitation, antibiotics and immune response through better nutrition and vaccination, the late-life debilitating effects of early-life infections have been partially ameliorated.

In short, many people have expected that a cure for aging may come in the form of a magic pill (an anti-aging drug of some sort). Nothing of the sort has happened of course. Instead, we have largely overlooked real and continuing progress in slowing the effects of aging, precisely because this progress has been so unanticipated and gradual.

For how long will this historical trend of aging amelioration continue? How far will it go? Can this beneficial process be accelerated? These are good questions to study alongside and in addition to the traditional search for anti-aging drugs.

My personal view is that future generations may be puzzled as to why we overlooked some simple and readily available medicine and technology, while spending so much time and money on expensive, complex dead-end projects. This is like sequencing the entire DNA sequence for scurvy patients instead of simply giving them a lemon...

Of course, aging is not as simple as scurvy. The most likely scenario for the future is a set of partial successes instead of one breakthrough. We need to understand the historical trends in amelioration of aging and try to accelerate it.

Perhaps we need to pay more attention to latent infections in early life, prevention of conditions leading to inflammation and radically change the whole culture of human nutrition. For example, encouraging accomplishments in smoking prevention in the United States gives some hope that perhaps similar efforts could be applied to the obesity epidemic in this country. Food which is high in vitamins, important minerals, micronutrients and fiber content, while being low in calories and animal fat may have a profound effect on further postponement of age-related degenerative diseases in later life. Research into calorie restriction offers confirming evidence for this supposition.

To summarize, we can now speak about a significant plasticity of aging rather than the old concept of immutable aging. In other words, aging effects can be altered and postponed. By acknowledging this, I do not wish to undermine the importance of future possible pharmacological medicines and technology and other promising approaches that include gene and stem cell therapy. On the contrary, these new experimental approaches may have a bright future, because even much simpler approaches do work!

The Current State of Aging Research

The current state of aging research is paradoxical. On the one hand, we hear about new exciting discoveries every month in the mass media. This creates the impression that aging studies are flourishing now. What we do not hear in the news are the many research opportunities lost due to insufficient funding and how desperate scientists have become in their attempts to secure funding for aging research. Currently only 10-20% of aging research projects are funded: most promising projects cannot even get started.

Much more generous funding of aging research is a key issue now, if we really wish to improve on current research efforts to understand and intervene in human aging.

Consider our research team, for example. We must currently spend more than a half of our professional time on paperwork just to obtain research funding: submission of proposals, revision in response to review comments and re-submission of the revised proposals is repeated over and over again! What a wastage of precious professional time, which could be used much more productively for research work itself! Our contacts with colleagues confirm that our situation is not unique. The waste of professional time and effort on paperwork is really quite alarming.

By now, our team has three promising research projects on aging and longevity studies, all of which belong to the "high risk - high gain" category, and therefore have no chance to be funded in a regular way. We would be delighted to pass these projects for consideration of private philanthropists like Bill Gates or George Soros, should they ever choose to support aging studies. With the support of private foundations (such the MacArthur Foundation), so many interesting and important projects on aging could be accomplished!

A radical improvement of the aging research funding is urgently needed if we wish to use the full creative potential of researchers, instead of wasting their time on paperwork.

Promising Avenues of Research

If we are interested in extension of healthy lifespan in humans, not just in fruit flies, then perhaps we need to pay more attention to human studies. If we wish to study humans and their lifespan, we must overcome two obstacles. Firstly, the opportunities for experiments that involve humans are limited. Secondly, studies on human lifespan may take too long a time to wait for answers.

Both problems could be resolved through epidemiological and biodemographic studies of human longevity. In other words, we collect and analyse data from experiments which Mother Nature has already performed with humans. This is the quantitative analysis of historical and genealogical data on human longevity, and it seems to be an extremely promising approach. These kinds of studies may provide us with new and important knowledge in a very short period of time.

These are not just words -- we have already developed a detailed research project for particularly promising avenues of research and even published it in the Journal of Anti-Aging Medicine as an article entitled "Epidemiology of human longevity: The search for appropriate methodology." (JAAM, 2001, 4(1): 13-30). This project could provide us with a decisive knowledge on the mechanisms of human longevity in just 5 years. The major obstacle in commencing this research is of course the lack of funding...

How do we know that these avenues of research are really promising? Well, we have already made some amazing preliminary findings. For example, we found a very unusual pattern of human lifespan inheritance. Traditionally, it was assumed that familial transmission of human lifespan from parents to children should follow a linear relationship. This is common to all other quantitative traits. In other words, each additional year of parental lifespan would be expected to provide the children with some fixed gain in average lifespan too. Quite contrary to these conventional expectations, we discovered a very different, threshold pattern of lifespan inheritance. There is no lifespan heritability if parental lifespan is below a threshold age of 75-85 years. There is a very strong heritability of human lifespan if parents live longer lives. These amazing preliminary findings are published as an article "When does human longevity start?: Demarcation of the boundaries for human longevity" in the Journal of Anti-Aging Medicine (JAAM, 2001, 4(2): 115-124).

We also found that early circumstances of human life (such as the month of birth) may have a profound effect 30 years later on the chances of survival. This is also quite remarkable. This finding indicates that there may have been critical periods early in human development that are particularly sensitive to historical seasonal variations in living conditions (seasonal vitamin deficiencies or seasonal exposure to pathogens, and so forth). We published an article "Season of Birth and Human Longevity" in Journal of Anti-Aging Medicine (JAAM, 1999, 2(4): 365-366) on this exciting topic and recently reconfirmed our initial findings on larger datasets.

Another promising avenue of research is related to our finding that paternal age at person's conception may be an important predictor of lifespan. This finding suggests that the mutation load or other genetic damage in paternal sperm cells may play a significant role in determining the length of human life.

Thus there are many exciting and promising avenues for future research. The only problem is in obtaining sufficient funding to accomplish them!

Obstacles For Anti-Aging Medicine

The most important current obstacle to anti-aging medicine is public confusion on the exact meaning and scientific credibility of anti-aging medicine. This confusion is reflected in the title of the recent scientific article "Is There an Antiaging Medicine?" published by the Journal of Gerontology (2002, volume 57A, number 9, pp. B333-B338).

The term "anti-aging medicine" is currently used by three disparate groups of people in three completely different ways: this is the root cause of confusion.

First, there is a large group of scientists who publish their research findings in the Journal of Anti-Aging Medicine and other related peer-reviewed scientific journals. For them, anti-aging medicine is the ultimate goal of their research work. It is future medicine and technology aimed at controlling the aging process by postponing, delaying, preventing and even reversing the deleterious effects of aging. By now, over a hundred important research articles have been published in the Journal of Anti-Aging Medicine. These articles are actively cited and used by the international scientific community.

If you make a search of scientific literature for the term "anti-aging" you will find that this term is routinely used now (like the terms "antioxidant" or "antibiotic", for example) in the texts of scientific articles, their abstracts, key words, and even titles. I have recently performed an analysis of the scientific literature and published these findings in the form of an article with a suitably self-explanatory title: "Scientific Legitimacy of the Term 'Anti-Aging.'" (Journal of Anti-Aging Medicine, 2002, 5(2): 239-240.). This article contains the list of legitimate anti-aging studies published in reputable journals by established researchers which use the term "anti-aging".

The second group of people who use the term "anti-aging medicine" are a class of medical practitioners. They are confronted with the real and often urgent health needs of their aged patients. For these physicians, "anti-aging medicine" is the everyday practice, often by trial and error, of alleviating, postponing, and hopefully even preventing or reversing some detrimental effects of aging.

These practitioners are a rather diverse group. Some of their activities are in fact very useful, such as the early detection and treatment of conditions that contribute to the accelerated progress of age-related degenerative diseases. For example the early detection and treatment of diabetes, hypertension, hypercholesterolemia, latent chronic infections, chronic inflammation, obesity, and vitamin or micronutrient deficiencies may postpone the onset of many detrimental effects of aging.

However, commercialization of the anti-aging industry has brought advertisement hype and spam. In some cases there is even a distinct smell of quackery and fraud. Unfortunately these marginal "anti-aging" groups are particularly noisy in their excessive advertisements. They are discrediting the very notion of anti-aging medicine in their efforts to make money.

Finally, there is a third group of people who believe that anti-aging interventions are neither possible nor desirable. They consider anti-aging medicine as "tampering with aging," which is both immoral and futile in their opinion. For them, "if it's 'anti-aging' it's quackery by definition" (Science, 2002, 295, page 1033). They select the most ridiculous and marginal cases of "anti-aging" quackery and expose them to the public, as if these cases are representative of anti-aging studies and anti-aging medicine.

How these obstacles to anti-aging medicine best be overcome ? Quite simply, we need to widely and effectively educate the public and even portions of the scientific community on the existence of legitimate anti-aging science with its legitimate goal of developing the foundations for future anti-aging medicine.

This educational work is already in progress. For example, the journal "Science" has recently published our consensus letter "Antiaging technology and pseudoscience", signed by Dr. Michael Fossel, the Editor-in-Chief for the Journal of Anti-Aging Medicine and by some other Editorial Board members of this journal, including myself. This publication did receive significant attention and initiated an interesting discussion published in Science online:

http://www.sciencemag.org/cgi/eletters/296/5568/656a

In this letter we clearly spelled out the difference between the scientific, peer-reviewed Journal of Anti-Aging Medicine, and the popular magazines that currently serve as advertisements for the anti-aging industry.

Still, a great deal more needs to be done to obtain wider support and recognition for anti-aging medicine as a legitimate goal of scientific research. To address this issue, a year ago we established a scientific and educational website entitled "Unraveling the Secrets of Human Longevity":

http://www.src.uchicago.edu/~gavr1/

This information resource contains over a hundred scientific documents supporting the ideas of anti-aging studies and has received about 34,000 visitors so far.

I would urge other researchers to join our efforts and contribute to the further development of anti-aging medicine by spreading the word!

Taking Up a Career in Aging Research

First, I would like to welcome new researchers and congratulate them for the choice they have made. Aging and longevity studies are so obviously important that they will provide a sense of purpose to your life and inspiration for further research.

My advice for researchers can be summarized in the following way:

1. Keep sight of the big picture and a broad vision of the problem.

In aging studies there is always the risk of being overwhelmed and distracted by details. There is also a temptation to adopt fancy new techniques at the expense of the initial goals of research.

You may find yourself missing the forest for the trees, trying to read a newspaper through an electron microscope or otherwise getting trapped in details. For example, there is current great interest in the study of differential gene expression during aging. However, aging may also be related to a simple decrease in the number of cells over time (a loss of failsafe redundancy in the body, in other words). You could overlook this important possibility while concentrating on detailed, fancy techniques.

2. Be persistent in your research efforts and prepared for occasional failure.

Scientific research is always at risk of failure. It is an exploration of unknown areas, often by trial and error. Therefore, consider failure not as an indicator of your research performance, but rather as a signal telling you to choose alternative research tactics.

Remember that aging studies are important. This will protect you from periods of frustration during occasional scientific failure. If you have a sense of the importance of your research work, you will find the strength to start again.

You must also be prepared for the failure to fund your research proposals. Here again, be responsive to criticism and change your tactics, but always be persistent in these strategic money matters.

3. Use the data-driven approach, instead of following a doctrine.

Theories of aging are very important. They allow us to organize accumulated facts into a comprehensive body of knowledge and plan further research. Yet researchers all too often become hostages of their own theories, falling into the trap of "adapting" facts to fit their concepts.

I advise treating aging theories a set of speculations or ideas that require further elaboration and validation. Keep an open mind and a critical vision. For any statement, claim or reported finding, one should seek alternative opinions and listen to their arguments carefully. Make final conclusions yourself, based on substance and facts rather than the apparent credibility of the sources. Famed authors and publications in prestigious scientific journals (on glossy paper!) may still be wrong. Be aware of conflicts of interests (follow the money that may produce deceptive claims). In difficult situations, rely on your common sense and choose outcomes that enable you to keep your peace of mind.

The Future of Aging and Anti-Aging Medicine

It is extremely important for researchers to understand the following:

It is up to us to bring about a revolution in life extension medicine!

If we convince ourselves and the public that nothing can or should be done with aging, this pronoucement will become a self-fulfilling prophecy. We will have thrown away the chance for longer, healthier lives for everyone.

In the past, the commitment of this nation has led to the completion of fantastic projects such as the flight to the Moon. Why should we consider this generation any less capable of great achievements? One such achievement could be the advent of practical, cheap, widely-available anti-aging medicine and technology.

The main challenge to accomplishing a revolution in life extension medicine and technology lies in the mobilization of national and public support for relevant research projects. From this perspective, recent attempts to discredit anti-aging research efforts and present them as a kind of scientific pornography should be taken very seriously indeed. In my opinion, these attempts should not be endorsed. Moreover, it would be very useful to establish a prestigious Anti-Aging Science Award in order to stimulate legitimate anti-aging scientific studies and the public support for these activities.

Anti-aging research projects will require large-scale and long-term intervention trials with human subjects. This will be very expensive and will require careful governmental supervision to minimize health risks. In other words, this ambitious anti-aging project would require mobilization of the nation and public support -- just as happened for the Apollo program and the flight to the Moon. One man cannot get to the Moon by collecting rocket fuel in his apartment, and one researcher cannot singlehandedly revolutionize anti-aging medicine.

A grand anti-aging project may even require the joint efforts of many nations, and this ambitious collaborative project may help to bring many nations together. Mankind has already seen the positive results of international scientific collaboration in many fields. Large anti-aging projects may help to further strengthen cooperation between nations.

With all this in mind, I believe it is important to bring the issue of aging prevention to the center of public debates now. By the next presidential elections, it could become a key political issue. We should not lose this opportunity to loudly express our opinions on anti-aging studies in public, and clearly make our supporting arguments heard. In accomplishing this, we can help to build the future that we deserve.

About the Author

Dr. Leonid Gavrilov obtained a Masters degree in chemistry (chemical kinetics and enzymology) and a Ph.D. in biology (genetics), both from Moscow State University, Russia. He then spent a decade of intensive research and self-education, writing a book "The Biology of Life Span" in conjunction with his wife Dr. Gavrilova, published in the United States in 1991.

"The Biology of Life Span" is selected and cited by the Encyclopaedia Britannica as a recommended reference on longevity. The book received positive reviews in a dozen scientific journals, including Nature, the British Medical Journal and BioEssays. It has been cited more than a hundred times in scientific literature.

Dr. Gavrilov is a recipient (Principal Investigator) of the Independent Scientist Award from the National Institute on Aging, NIH. He and his wife have recently developed and published a new unifying theory of aging and longevity based on reliability theory. This new theory provides a general explanation of aging for organisms as well as technical devices. It was published by the Journal of Theoretical Biology and received media attention (including the journal "The Scientist").

Dr. Gavrilov has developed a course "Biodemography of Human Mortality and Longevity," and teaches at the University of Chicago. His recent scientific article "Evolutionary Theories of Aging and Longevity" was written and published largely thanks to teaching activities.

Dr. Gavrilov currently works at the Center on Aging, NORC/ University of Chicago.