LONGEVITY MEME NEWSLETTER
April 07 2008
The Longevity Meme Newsletter is a weekly e-mail containing news, opinions and happenings for people interested in healthy life extension: making use of diet, lifestyle choices, technology and proven medical advances to live healthy, longer lives.
- Don't Lose Yourself In Dietary Minutiae
- Longevity In Other Species
- Latest Healthy Life Extension Headlines
DON'T LOSE YOURSELF IN DIETARY MINUTIAE
Far, far too many people spend the time they devote to thinking about health and longevity in worrying over trivial, inconsequential choices in diet and supplementation, all the while leading a lifestyle that greatly harms their future prospects through lack of exercise and being overweight. It makes no sense to throw oneself into the pursuit of small, uncertain health benefits when large, reliable health benefits are right at hand - but people do just that:
"It is reasonable to state, bluntly, that you or I can reliably engineer no greater chance of improving our natural long-term health than by simply eating sensibly, practicing calorie restriction (which pretty much forces eating sensibly on you), exercising regularly, and taking a sane multivitamin. Anything more than that, and you have to accept that you're tinkering with no real way of knowing whether you're gaining any benefit. Not that there's anything wrong with that as a hobby, but don't delude yourself into thinking that you can eat as much as you like and top it off with blueberries to at least make something better."
Beyond the matter of what you can do with your health today, you should remember that nothing other than major advances in medical science will reliably let you live to see 100 years of age. The true road to the future of longevity is through supporting medical research aimed at engineering that longevity. Best we all get working on that, right?
LONGEVITY IN OTHER SPECIES
Humans are long-lived in comparison to similarly-sized mammals, but some other species manage far greater feats of comparative longevity - and a few appear not to age at all, so far as scientists can determine at this time. Can we learn anything from their biochemistry?
"How is it that a whale can resist cancer effectively enough to live for two centuries in the wild, bearing in mind a whale has so many, many more cells than we humans that might become cancerous. How does the construction of naked mole-rat cellular membranes allow them to shrug off oxidative damage and live nine times longer than similar rodent species? Why do lobsters - and possibly some species of clam - seem not to age at all?"
The highlights and headlines from the past week follow below.
Remember - if you like this newsletter, the chances are that your friends will find it useful too. Forward it on, or post a copy to your favorite online communities. Encourage the people you know to pitch in and make a difference to the future of health and longevity!
LATEST HEALTHY LIFE EXTENSION HEADLINES
To view commentary on the latest news headlines complete with links and references, please visit the daily news section of the Longevity Meme: http://www.longevitymeme.org/news/
How Lipofuscin Harms Your Cells (April 04 2008)
A fairly clear description of the way aggregates like lipofuscin, which your body cannot break down but nonetheless accumulate through the normal operation of your metabolism, harm your cells: "The most striking morphological change in neurons during normal aging is the accumulation of autophagic vacuoles filled with lipofuscin or neuromelanin pigments. These organelles are similar to those containing the [lipofuscin] associated with neurological disorders, particularly in diseases caused by lysosomal dysfunction. [Lipofuscin and pigments] arise from incompletely degraded proteins and lipids principally derived from the breakdown of mitochondria, or products of oxidized catecholamines. Pigmented autophagic vacuoles may eventually occupy a major portion of the neuronal cell body volume, due to resistance of the pigments to lysosomal degradation and/or inadequate fusion of the vacuoles with lysosomes." As long-lived cells are bloated by vacuoles containing material they can't get rid of, they cease to behave correctly, leading to degeneration and disease. Repairing and preventing this state of affairs requires research like the LysoSENS program, aiming for ways to safely break down lipofuscin and other damaging materials.
Climate Variability and the Evolution of Longevity (April 04 2008)
A recent paper suggests that resistance to climatic variablity might be one reason why increased longevity can win out in an evolutionary battle with short lived species that reproduce more rapidly: "We analyzed multiyear demographic data for 36 plant and animal species with a broad range of life histories and types of environment to ask how sensitive their long-term stochastic population growth rates are likely to be to changes in the means and standard deviations of vital rates (survival, reproduction, growth) in response to changing climate. ... Short-lived species (insects and annual plants and algae) are predicted to be more strongly (and negatively) affected by increasing vital rate variability relative to longer-lived species (perennial plants, birds, ungulates). ... Our results highlight the potential vulnerability of short-lived species to an increasingly variable climate." You might also recall other work suggesting that crowding effects can lead to runaway evolution of extreme longevity.
Simple Nanomedicine: the Power of Targeting (April 03 2008)
You might recall a 2006 technology demonstration in which comparatively simple nanoparticles were used to deliver the toxin fumagillin to sites of errant blood vessel formation, and thus disrupt atherosclerotic plaques without otherwise damaging the patient. Here, ScienceDaily reports on the same approach directed to attack cancer: "The nanoparticles are extremely tiny beads of an inert, oily compound that can be coated with a wide variety of active substances. ... the researchers describe a significant reduction of tumor growth in rabbits that were treated with nanoparticles coated with a fungal toxin called fumagillin. ... In addition to fumagillin, the nanoparticles' surfaces held molecules designed to stick to proteins found primarily on the cells of growing blood vessels. So the nanoparticles latched on to sites of blood vessel proliferation and released their fumagillin load into blood vessel cells. Fumagillin blocks multiplication of blood vessel cells, so it inhibited tumors from expanding their blood supply and slowed their growth." Precisely targeted chemotherapy is being demonstrated to be a more effective chemotherapy, lacking in unpleasant side-effects. This sort of technology is a foundation for highly effective, painless cancer therapies.
Generating the Cells Needed For Therapy (April 03 2008)
Regenerative medicine and tissue engineering require the ability to create cells to order, and researchers are presently working to produce that infrastructure. Illustrative work to that end via EurekAlert!: "a major stumbling block to developing new treatments has been the difficulty scientists have faced ensuring the stem cells turn into the type of cell required for any particular condition - in the case of diabetes, pancreatic cells. ... Unprompted, the majority of stem cells turn into simple nerve cells called neurons. Less than one per cent of embryonic stem cells would normally become insulin-producing pancreatic cells, so the challenge has been to find a way of producing much greater quantities of these cells. ... The team found that the transcription factor PAX4 encouraged high numbers of embryonic stem cells - about 20% - to become pancreatic beta cells with the potential to produce insulin when transplanted into the body. Furthermore, the scientists for the first time were able to separate the new beta cells from other types of cell produced using a technique called 'fluorescent-activated cell sorting' which uses a special dye to colour the pancreatic cells green."
On Skin Cancer Stem Cells (April 02 2008)
Many cancers are driven by cancer stem cells, and these errant stem cell populations have characteristic differences that can be exploited. From the Telegraph: "A new way to fight a common form of skin cancer has resulted from the discovery of how the uncontrollable growth of the tumour is driven by rogue cells. ... a protein known as beta-catenin is crucial for sustaining these cancer stem cells - in genetically engineered animals without this protein, the tumours shrink because there is no longer a signal to tell the cells to keep renewing themselves. The team's discovery may open up a possible route to treating this type of skin cancer in humans by blocking this protein because they found that squamous cell carcinomas - the human equivalent of the mouse tumours - also rely on beta-catenin. As the stem cells responsible for renewing normal skin do not depend on beta-catenin, targeting this molecule could help wipe out the cancer stem cells in a malignant tumour."
Self-Assembling Nanoscaffolds For Nerve Regeneration (April 02 2008)
Researchers continue to work on methods of nerve regeneration. Here's one via ScienceDaily: "spinal cord injury often leads to permanent paralysis and loss of sensation below the site of the injury because the damaged nerve fibers can't regenerate. The nerve fibers or axons have the capacity to grow again, but don't because they're blocked by scar tissue that develops around the injury. ... researchers have shown that a new nano-engineered gel inhibits the formation of scar tissue at the injury site and enables the severed spinal cord fibers to regenerate and grow. The gel is injected as a liquid into the spinal cord and self-assembles into a scaffold that supports the new nerve fibers as they grow up and down the spinal cord, penetrating the site of the injury. When the gel was injected into mice with a spinal cord injury, after six weeks the animals had a greatly enhanced ability to use their hind legs and walk."
Nuts and Bolts of Vitrification (April 01 2008)
Learn more about vitrification in the cryonics industry at Depressed Metabolism: "A major public misperception is that cryonics involves the freezing of dead people. The objective of cryonics is not to preserve dead people with the hope of future revival but to place critically ill patients in a state of biostasis until a time when more advanced medical technologies might be available to treat and cure them. Currently, all major cryonics organizations induce metabolic arrest of the brain by attempting vitrification rather than freezing. Unless a patient has suffered a long period of circulatory arrest, after which perfusion of the body or brain is no longer possible, metabolic arrest is induced by cooling down the patient to cryogenic temperatures. Vitrification can be defined as 'the process of converting a material into a glass-like amorphous solid that is free from any crystalline structure.' Because vitrification of pure water would require extremely rapid cooling rates, vitrification in cryonics is achieved by substituting the water of patients with a highly concentrated cryoprotectant agent before cooling."
Progress in Medical Nanomachinery (April 01 2008)
Researchers are already moving beyond complex nanoparticles and into the realm of the first simple medical nanomachines. Via EurekAlert!: "Known as a 'nanoimpeller,' the device is the first light-powered nanomachine that operates inside a living cell, a development that has strong implications for cancer treatment. ... Nanomaterials suitable for this type of operation must consist of both an appropriate container and a photo-activated moving component. ... researchers used mesoporous silica nanoparticles and coated the interiors of the pores with azobenzene, a chemical that can oscillate between two different conformations upon light exposure. Operation of the nanoimpeller was demonstrated using a variety of human cancer cells, including colon and pancreatic cancer cells. The nanoparticles were given to human cancer cells in vitro and taken up in the dark. When light was directed at the particles, the nanoimpeller mechanism took effect and released the contents. The pores of the particles can be loaded with cargo molecules, such as dyes or anticancer drugs. In response to light exposure, a wagging motion occurs, causing the cargo molecules to escape from the pores and attack the cell. ... impeller operation can be regulated precisely by the intensity of the light, the excitation time and the specific wavelength."
Another Path to Dopamine Neurons (March 31 2008)
EurekAlert! reports on another of the many teams working to create a cost-effective source of dopamine-producing neurons to replace those lost in Parkinson's disease: "Previously, we were able to coax these multipotent [uterine] stem cells to differentiate into cartilage cells. Now we have found that we can turn uterine stem cells into neurons that can boost dopamine levels and partially correct the problem of Parkinson’s disease ... The stem cells in this study were derived from human endometrial stromal cells that were cultured under conditions that induce the creation of neurons. These cells then developed axon-like projections and cell bodies with a pyramid shape typical of neurons. ... The dopamine levels in the mice increased once we transferred the stem cells into their brains. The implications of our findings are that women have a ready supply of stem cells that are easily obtained, are differentiable into other cell types, and have great potential use for other purposes."
More Thoughts on Engineered Longevity (March 31 2008)
Over at Philosophy Now, an example of moderate, sensible support for the engineering of greater human longevity, and rejection of a variety of foolish arguments against that goal: "despite large increases in life span, the length of the period of illness before death is remaining steady, and the proportion of life spent ill is declining. ... Even this welcome prospect does not satisfy some miserabilists: 'We cannot afford all these old people' is the cry. Hidden in that statement is the assumption that old people, even in good health (as most are), are not going to contribute to the wealth of the nation. There is, of course, no reason why they too should not be producers - so long as they are not prevented from doing so by negative expectations and ageist attitudes, and policies ensuring that those negative expectations are fulfilled. ... We may anticipate therefore that for many, perhaps most people in developed countries, average healthy, productive life expectancy will increase indefinitely."