Health Article

The trend in human longevity is upward, but how much of that is due to unintended slowing of the aging process via general advances in medicine and better treatment of the diseases of aging? A paper: "The distinction between senescent and non-senescent mortality proves to be very valuable for describing and analysing age patterns of death rates. Unfortunately, standard methods for estimating these mortality components are lacking. The first part of this paper discusses alternative methods for estimating background and senescent mortality among adults and proposes a simple approach based on death rates by causes of death. The second part examines trends in senescent life expectancy (i.e., the life expectancy implied by senescent mortality) and compares them with trends in conventional longevity indicators between 1960 and 2000 in a group of 17 developed countries with low mortality. Senescent life expectancy for females rises at an average rate of 1.54 years per decade between 1960 and 2000 in these countries. The shape of the distribution of senescent deaths by age remains relatively invariant while the entire distribution shifts over time to higher ages as longevity rises."

View the Article Under Discussion: http://pmid.us/19851933
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This seems potentially important: "Despite a 30-year lifespan that gives ample time for cells to grow cancerous, a small rodent species called a naked mole rat has never been found with tumors of any kind - and now [biologists] think they know why. ... the mole rat's cells express a gene called p16 that makes the cells 'claustrophobic,' stopping the cells' proliferation when too many of them crowd together, cutting off runaway growth before it can start. The effect of p16 is so pronounced that when researchers mutated the cells to induce a tumor, the cells' growth barely changed ... Like many animals, including humans, the mole rats have a gene called p27 that prevents cellular overcrowding, but the mole rats use another, earlier defense in gene p16. Cancer cells tend to find ways around p27, but mole rats have a double barrier that a cell must overcome before it can grow uncontrollably. ... It's very early to speculate about the implications, but if the effect of p16 can be simulated in humans we might have a way to halt cancer before it starts. ... We haven't come across this anticancer mechanism before because it doesn't exist in the two species most often used for cancer research: mice and humans. Mice are short-lived and humans are large-bodied. But this mechanism appears to exist only in small, long-lived animals."

View the Article Under Discussion: http://www.eurekalert.org/pub_releases/2009-10/uor-sdg102609.php
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/

Opinions from a bioethicist on how researchers should present the case for longevity science in order to maximize fundraising and public support: "The medical sciences are currently dominated by the 'disease-model' approach to health extension, an approach that prioritizes the study of pathological mechanisms with the goal of discovering treatment modalities for specific diseases. This approach has marginalized research on the aging process itself, research that could lead to an intervention that retards aging, thus conferring health dividends that would far exceed what could be expected by eliminating any specific disease of aging. This paper offers a diagnosis of how this sub-optimal approach to health extension arose and some general prescriptions concerning how progress could be made in terms of adopting a more rational approach to health extension. Drawing on empirical findings from psychology and economics, 'prospect theory' is applied to the challenges of 'framing' the inborn aging process given the cognitive capacities of real (rather than rational) decision-makers under conditions of risk and uncertainty. Prospect theory reveals that preferences are in fact dependent on whether particular outcomes of a choice are regarded as 'a loss' or 'a gain', relative to a reference point (or 'aspiration level for survival'). And this has significant consequences for the way biogerontologists ought to characterise the central aspirations of the field (i.e. to prevent disease versus extend lifespan)." Personally, I'm more in favor of entirely the opposite approach - don't adapt your argument to the suboptimal cultural environment, but rather work to change that cultural environment.

View the Article Under Discussion: http://colinfarrelly.blogspot.com/2009/10/biogerontology-paper-on-framing-inborn.html
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Progress continues in the development of biochemically active scaffolding to sculpt and guide tissue regeneration: here, ScienceDaily looks at a scaffold "made from soluble fibers, which may help humans replace lost or missing bone. With more research, [it] could also serve as the basic technology for regenerating other types of human tissues, including muscle, arteries, and skin. ... The bioactive agents that spur bone and tissue to regenerate are available to us. The problem is that no technology has been able to effectively deliver them to the tissue surrounding that missing bone. [This] artificial and flexible scaffolding connects tissues together as it releases growth-stimulating drugs to the place where new bone or tissue is needed - like the scaffolding that surrounds an existing building when additions to that building are made. ... The [scaffold material] could be used to restore missing bone in a limb lost in an accident, or repair receded jawbones necessary to secure dental implants ... The scaffold can be shaped so the bone will grow into the proper form. After a period of time, the fibers can be programmed to dissolve, leaving no trace."

View the Article Under Discussion: http://www.sciencedaily.com/releases/2009/10/091019122844.htm
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/

A look at some scientific studies of the present bounds of human longevity from Courant: "It's becoming clear that people who break through the 90-plus barrier represent a physical elite, markedly different from the elderly who typically die younger than them. Far from gaining a longer burden of disability, their extra years are often healthy ones. They have a remarkable ability to live through, delay or entirely escape a host of diseases that kill off most of their peers. Supercentenarians - people aged 110 or over - are even better examples of aging gracefully. ... As a demographic group, they basically didn't exist in the 1970s or '80s. They have some sort of genetic booster rocket and they seem to be functioning better for longer periods of time than centenarians. ... The average supercentenarian had freely gone about their daily life until the age of 105 or so, some five to 10 years longer even than centenarians, who are themselves the physical equivalent of people eight to 10 years their junior. This isn't just good news for the oldest old and for society in general; it also provides clues about how more of us might achieve a long and healthy old age."

View the Article Under Discussion: http://www.courant.com/health/sns-200910201351tmspremhnstr--k-h20091021oct21,0,4810521,full.story
Read More Longevity Meme Commentary: http://www.longevitymeme.org/news/