Gerontology: Difference between revisions

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==Life Expectancy==
==Life Expectancy==


One of the major demographic fallacies that the study of human aging has cleared up is the somewhat bizarre notion that life expectancy was dramatically shorter in the past than at present. This view is seemingly made more plausible by the dramatic increases in life expectancy (and comparable increases in height) that have, in fact, occurred during the past century. Thus, it is not at all unusual to encounter suggestions that human life expectancy at the dawn of the agricultural revolution 10,000 BC was 14 years old, and later, during the Roman Empire was 21 years old. This is a purely statistical anomaly; demographers do not actually compute individual life expectancy, but rather the ''average'' life expectancy of populations, and therein lies a world of difference. In fact, the dramatic increases in life expectancy in the century since 1900 have, until recent decades, been almost entirely due to dramatic ''decreases'' in infant and childhood mortality.  
One of the major demographic fallacies that the recent study of human aging in gerontology has cleared up is the notion that life expectancy was dramatically shorter in the past than at present. While there is no doubt that there have been major increases in life expectancy over the past century, until quite recently these were due almost exclusively to decreases in infant mortality. The view that modern humans in general live dramatically longer than earlier humans is seemingly made more plausible by earlier, and even more dramatic, increases in life expectancy (and comparable increases in height) that have, in fact, occurred in the past several millenia. Thus, it is not at all unusual to encounter suggestions that overall human life expectancy at the dawn of the agricultural revolution 10,000 BC was 14 years old, and later, during the Roman Empire rose only to 21 years old. All of this is largely a statistical anomaly; demographers do not actually compute ''individual'' life expectancy, but rather the ''average'' life expectancy of populations, and therein lies a world of difference. In reality, the dramatic quantitative increases in average life expectancy between 1900 and 2000 have been largely due to dramatic ''decreases'' in infant and childhood mortality. It wasn't so much that people, on the whole were living dramatically longer, as it was that vastly ''more'' people were surviving the first years of life.


There is a vast difference between that average life expectancy and the human life span. The Old Testament speaks of people living "three score and ten", suggesting that even several thousand years ago, adults who survived childhood may have lived seventy years. A human population that normally lived only 14 years would be seriously on the verge of extinction, since sizeble proportions of 14 year olds would not be '
There is a vast difference between average life expectancy statistics and the human life span. The Old Testament speaks of people living "three score and ten" as the fullness of life, suggesting that even several thousand years ago, adults who survived childhood may have expected to lived seventy years. A human population that normally lived only 14 years would be seriously on the verge of extinction. There is no evidence to suggest rapid evolution upward in the age of puberty within the last few thousand years. Thus, since sizeble proportions of 14 year olds would not even have reached sexual maturity, and, even if sexually mature at 10, would not have lived long enough to successful raise their children. Although a life span of 21 years would be more plausible from a reproductive standpoint, documentary evidence from the Roman Empire also largely refutes this notion: "[[Pliny the Elder]]" did not die at the ripe old age of 22!


Note that some early pioneers, such as [[Michel-Eugene Chevreul]], who himself lived to be 102 in the 1880s, believed that aging itself should be a science to be studied. The word itself was coined circa 1903.<ref>[http://www.etymonline.com/index.php?term=gerontology Online Etymology Dictionary<!-- Bot generated title -->]</ref>
Note that some early pioneers, such as [[Michel-Eugene Chevreul]], who himself lived to be 102 in the 1880s, believed that aging itself should be a science to be studied. The word gerontology itself was coined circa 1903.<ref>[http://www.etymonline.com/index.php?term=gerontology Online Etymology Dictionary<!-- Bot generated title -->]</ref>


It was not until the 1940s, however, that pioneers like [[James Birren]] began organizing 'gerontology' into its own field. Recognizing that there were experts in many fields all dealing with the elderly, it became apparent that a group like the [[Gerontological Society of America]] was needed (founded 1945).
The reasons for the rising interest in the study of aging are to be found in demographic changes that began silently around the start of the twentieth century. It was not until the 1940s, however, that pioneers like [[James Birren]], [[Clark Tibbitts]], [[Wilma Donahue]], and others began organizing 'gerontology' into a recognized field of study. Recognizing that there were experts in many fields all dealing with the elderly, it became apparent that a national [[professional association]] of researchers and practitioners was needed. The  [[Gerontological Society of America]] was founded 1945.


In the 1950s to the 1970s, the field was mainly social and concerned with issues such as nursing homes and health care. However, research by [[Leonard Hayflick]] in the 1960s (showing that a cell line culture will only divide about 50 times) helped lead to a separate branch, [[biogerontology]]. It became apparent that simply 'treating' aging wasn't enough. Finding out about the aging process, and what could be done about it, became an issue.  
In the 1950s to the 1970s, the field was mainly social and concerned with issues such as nursing homes and health care. However, research by [[Leonard Hayflick]] in the 1960s (showing that a cell line culture will only divide about 50 times) helped lead to a separate branch, [[biogerontology]]. It became apparent that simply 'treating' aging wasn't enough. Finding out about the aging process, and what could be done about it, became an issue.  

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Gerontology (from Greek: γερο, gero, "old age"; and λόγος, logos, "speech" lit. "to talk about old age") is the study of the social, psychological and biological aspects of aging. It is distinguished from geriatrics, which is the branch of medicine that studies the disease of the elderly.

Gerontology includes these and other endeavors:

  • studying physical, mental, and social changes in people as they age;
  • investigating the aging process itself (biogerontology);
  • investigating the effects of our aging population on society, including the fiscal effects of pensions, entitlements, life and health insurance, and retirement planning;
  • applying this knowledge to policies and programs, including a macroscopic (i.e. government planning) and microscopic (i.e. running a nursing home) perspective.

The multidisciplinary focus of gerontology means that there are a number of sub-fields, as well as associated fields such as psychology and sociology that also cross over into gerontology. However, that there is an overlap should not be taken as to construe that they are the same. For example, a psychologist may specialize in early adults (and not be a gerontologist) or specialize in older adults (and be a gerontologist).

The field of gerontology was developed relatively late, and as such often lacks the structural and institutional support needed (for example, relatively few universities offer a Ph.D. in gerontology). Yet the huge increase in the elderly population in the post-industrial Western nations has led to this becoming one of the most rapidly growing fields. As such, gerontology is currently a well-paying field for many in the West.

Biogerontology

For more information, see: Life extension.


Biogerontology, is the subfield of gerontology dedicated to studying the biological processes involved in aging. Some have looked to develop theories of the aging process, such as telomere shortening, the free radical theory, and the like. Some skeptics have worked to show that aging is a biological process that we are far from being able to control. Conservative biogerontologists who have only an intellectual interest in the aging process, like Leonard Hayflick, have predicted that the human life expectancy numbers will top out at about 85 (88 for females, 82 for males).

Biomedical gerontology also known as experimental gerontology and life extension, is a sub discipline of biogerontology, that endeavors to slow, prevent, and even reverse aging in both humans and animals. Curing age-related diseases is one approach, and slowing down the underlying processes of aging is another. Most 'life extensionists' believe the human life span can be altered within the next century, if not sooner. 'Optimists' have predicted a changing human life span, though this has not yet been demonstrated.

Many biogerontologists take an intermediate position, emphasizing the study of the aging process as a means of mitigating aging-associated diseases, while denying that maximum life span can be altered (or denying that it is desirable to try).

Notable biogerontologists

Notable biomedical gerontologists

Notable biogerotechnologists (business/applied)

Notable demographic gerontologists

Notable non-biomedical biogerontologists

Social gerontology

Social gerontology is a multi-disciplinary sub-field that specializes in studying or working with older adults.

Social gerontologists may have degrees or training in social work, nursing, psychology, sociology, demography, gerontology, or other social science professions. Gerontologists are responsible for educating, researching, and advancing the broader causes of older people by giving informative presentations, publishing books and articles that pertain to the aging population, producing relevant films and television programs, and producing new graduates of these various disciplines in college and university settings.

Because issues of life span and life extension need numbers to quantify them, there is an overlap with demography. Those that study the demography of the human life span are different than those that study the social demographics of aging.

Notable social gerontologists

Notable social gerontologists of the past half century include:

Life Expectancy

One of the major demographic fallacies that the recent study of human aging in gerontology has cleared up is the notion that life expectancy was dramatically shorter in the past than at present. While there is no doubt that there have been major increases in life expectancy over the past century, until quite recently these were due almost exclusively to decreases in infant mortality. The view that modern humans in general live dramatically longer than earlier humans is seemingly made more plausible by earlier, and even more dramatic, increases in life expectancy (and comparable increases in height) that have, in fact, occurred in the past several millenia. Thus, it is not at all unusual to encounter suggestions that overall human life expectancy at the dawn of the agricultural revolution 10,000 BC was 14 years old, and later, during the Roman Empire rose only to 21 years old. All of this is largely a statistical anomaly; demographers do not actually compute individual life expectancy, but rather the average life expectancy of populations, and therein lies a world of difference. In reality, the dramatic quantitative increases in average life expectancy between 1900 and 2000 have been largely due to dramatic decreases in infant and childhood mortality. It wasn't so much that people, on the whole were living dramatically longer, as it was that vastly more people were surviving the first years of life.

There is a vast difference between average life expectancy statistics and the human life span. The Old Testament speaks of people living "three score and ten" as the fullness of life, suggesting that even several thousand years ago, adults who survived childhood may have expected to lived seventy years. A human population that normally lived only 14 years would be seriously on the verge of extinction. There is no evidence to suggest rapid evolution upward in the age of puberty within the last few thousand years. Thus, since sizeble proportions of 14 year olds would not even have reached sexual maturity, and, even if sexually mature at 10, would not have lived long enough to successful raise their children. Although a life span of 21 years would be more plausible from a reproductive standpoint, documentary evidence from the Roman Empire also largely refutes this notion: "Pliny the Elder" did not die at the ripe old age of 22!

Note that some early pioneers, such as Michel-Eugene Chevreul, who himself lived to be 102 in the 1880s, believed that aging itself should be a science to be studied. The word gerontology itself was coined circa 1903.[8]

The reasons for the rising interest in the study of aging are to be found in demographic changes that began silently around the start of the twentieth century. It was not until the 1940s, however, that pioneers like James Birren, Clark Tibbitts, Wilma Donahue, and others began organizing 'gerontology' into a recognized field of study. Recognizing that there were experts in many fields all dealing with the elderly, it became apparent that a national professional association of researchers and practitioners was needed. The Gerontological Society of America was founded 1945.

In the 1950s to the 1970s, the field was mainly social and concerned with issues such as nursing homes and health care. However, research by Leonard Hayflick in the 1960s (showing that a cell line culture will only divide about 50 times) helped lead to a separate branch, biogerontology. It became apparent that simply 'treating' aging wasn't enough. Finding out about the aging process, and what could be done about it, became an issue.

The biogerontological field was also bolstered when research by Cynthia Kenyon and others demonstrated that life extension was possible in lower life forms such as fruit flies, worms, and yeast. So far, however, nothing more than incremental (marginal) increases in life span have been seen in any mammalian species.

Today, social gerontology remains the largest sector of the field, but the biogerontological side is seen as being the 'hot' side.[9] Indeed, some have said that social gerontologists look to the past; biogerontologists look to the future.

Academic resources

  • Journal of Applied Gerontology, ISSN: 1552-4523 (electronic) ISSN: 0733-4648 (paper), SAGE Publications
  • Age and Aging, an international journal publishing refereed original articles on geriatric medicine and gerontology. Oxford University Press. 6 issues / 12 months. ASIN: B00006LAGZ ISSN:


References

  1. ↑ Guarente, L. and F. Picard, Calorie restriction--the SIR2 connection. Cell, 2005. 120(4): p. 473-82.
  2. ↑ 1. Kaeberlein, M., M. McVey, and L. Guarente, The SIR2/3/4 complex and SIR2 alone promote longevity in Saccharomyces cerevisiae by two different mechanisms. Genes Dev, 1999. 13(19): p. 2570-80.
  3. ↑ Kaeberlein, M., et al., Regulation of yeast replicative life span by TOR and Sch9 in response to nutrients. Science, 2005. 310(5751): p. 1193-6.
  4. ↑ Kaeberlein, M., et al., Sir2-independent life span extension by calorie restriction in yeast. PLoS Biol, 2004. 2(9): p. E296.
  5. ↑ Kaeberlein, M., et al., Regulation of yeast replicative life span by TOR and Sch9 in response to nutrients. Science, 2005. 310(5751): p. 1193-6.
  6. ↑ Howitz, K.T., et al., Small molecule activators of sirtuins extend Saccharomyces cerevisiae lifespan. Nature, 2003. 425(6954): p. 191-6.
  7. ↑ SpringerLink - Journal Article
  8. ↑ Online Etymology Dictionary
  9. ↑ Roy Walford and the immunologic theory of aging
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