LONGEVITY MEME NEWSLETTER
July 21 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.
- Gregory Stock at Aging 2008
- Cancer and Immune System Proficiency
- Latest Healthy Life Extension Headlines
GREGORY STOCK AT AGING 2008
A transcript of Gregory Stock's presentation at Aging 2008 last month, with a focus on how the mainstream of present day aging research must change:
"What is interesting is that [healthy life extension] is not the goal of biogerontology today. Its goal is not to control aging, or extend our natural lifespan, but to somehow compress morbidity, so that we can be healthier for a longer period of time and then fade away quickly. Initially that sounds reasonable, but at its logical conclusion, it really is completely out of sync with our aspirations."
The most important cultural battle of our time is taking place inside the gerontological community. It is the fight to build a research community whose members eagerly and vocally work to achieve the repair of aging and defeat of age-related degeneration. At present that community is in only its earliest stages. The rest of the field is still mired in the views of yesterday: a place where no-one can talk about healthy life extension for fear of ridicule and loss of funding opportunities:
Societies have a way of working themselves into a conservatism that holds back progress. This is slowly changing in the aging research community, but that change must accelerate if we are to see significant progress in longevity science within our lifetime.
CANCER AND IMMUNE SYSTEM PROFICIENCY
Are some immune systems much better than others at destroying cancer in its earliest stages? It seems that this is the case. Can we copy that proficiency and use it as a therapy? The prospects look promising:
"First, we had cancer-resistant mice and asked, 'What can we learn from it?' The reason it's resistant is because it has very different white cells. So then that immediately prompted the concept of therapy, because you can easily transfer white cells. You can extract them as a therapeutic agent and give them to another mouse. It's a therapy. It's much better than to find the gene. If you find the gene, then you have to understand the mechanism, and you have to find a way to put the gene into the cell, into all the cells you want to, and that would not work very easily. The technology as we speak right now is not really mature for that area. You might have to wait another 10, 20 years before that technology catches up with the concept. However, what we found is a cell as a therapeutic agent, so why not go ahead and see how it works. It worked really well in mice, so the next question, very obviously, is can we find a similar cancer resistance for humans as a donor for a therapeutic agent. And the answer is yes, we did find quite a few of them "
From a broad assessment of cutting edge cancer research, it seems that we are well on the way to turning cancer into a controllable chronic illness. You'll have outbreaks, they'll be caught early, and the medicine of the 2020s will eliminate them. The question is whether this is good enough: is a comprehensive suite of low-risk, safe cancer cures enough to remove cancer as a threat whilst our lives are extended by other medical technologies?
"The risk of cancer in any tissue increases with age - and as for most failing machines, quite dramatically so in later life. This stems from underlying changes in biochemistry and the simple rules that determine failure rates in machinery based on gradual wear in component parts - possibly the shortening of your telomeres, possibly damage to stem cells, possibly something else, possibly all of the above. Is it good enough to have a good after-the-fact cure on hand when the risk of occurrence is increasing enormously with each passing year? Is there a point past which a good therapy is just overloaded by sheer weight of new cancer bursting from your cells, and where does that point occur?"
How much time does the cure for cancer buy us? Ultimately, we will need to change our biology to remove cancer risk entirely. Aubrey de Grey has proposed a path to that end:
Other ways forward will no doubt be discovered in the years ahead.
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/
Metabolic Rate and Longevity (July 18 2008)
As an addendum to prior discussions of the plasma membrane theory of longevity and related metabolic rate correlations: "Metabolism is a defining feature of all living organisms, with the metabolic process resulting in the production of free radicals that can cause permanent damage to DNA and other molecules. Surprisingly, birds, bats and other organisms with high metabolic rates have some of the slowest rates of senescence begging the question whether species with high metabolic rates also have evolved mechanisms to cope with damage induced by metabolism. To test whether species with the highest metabolic rates also lived the longest I determined the relationship between relative longevity (maximum lifespan), after adjusting for annual adult survival rate, body mass and sampling effort, and mass-specific field metabolic rate (FMR) in 35 species of birds. There was a strongly positive relationship between relative longevity and FMR, consistent with the hypothesis. This conclusion was robust to statistical control for effects of potentially confounding variables such as age at first reproduction, latitude and migration distance, and similarity in phenotype among species because of common phylogenetic descent. Therefore, species of birds with high metabolic rates senesce more slowly than species with low metabolic rates."
Complicating Alzheimer's Disease (July 18 2008)
Researchers have demonstrated an Alzheimer's therapy that removes amyloid plaque, but that doesn't halt or reverse neurodegeneration: "The theory was that dementia could be slowed or reversed once the plaques were cleared, and experiments in animals have shown that removing these plaques improves brain function. ... long-term follow-up of Alzheimer's patients treated with [the therapy] did show, 'a reduction in the number of plaques in the brains of patients -- in some cases there was a virtually complete removal of plaques. Crucially, there was no evidence that the patients benefited by the removal of plaques and even those subjects with virtually complete removal continued to deteriorate and had severe end-stage dementia prior to their death.' ... [researchers now believe] that removing plaques - at least by this method - is unlikely to make a significant difference to the clinical outcome of patients with established Alzheimer's disease ... it strongly suggests that plaques are not sufficient on their own to account for disease progression."
On Predicting Longevity (July 17 2008)
For all the obvious reasons, actuaries would love to be able to predict human longevity with accuracy. But is that possible with present or near-future tools, even setting aside considerations of rapid progress in biotechnologies of rejuvenation? Researcher Leonid Gavrilov here excerpts some of a recent paper on that subject: "Who has a better chance to become a centenarian - a taller or a shorter person? Is it better to be slender or stout? We know that most centenarians are both short and slender in their body build, but these measurements made at older ages could be misleading because they might only reflect body shrinkage as a result of aging. We were also intrigued by other possible predictors of long life. Is it better to be a farmer or an actuary in order to survive to 100? Does the number of children a person has affect their chances to celebrate their 100th birthday? Is it better to have dark eyes or light eyes? All these personal characteristics could be useful for actuaries if a strong association between them and exceptional longevity were to be established."
The Broadening Search For Longevity Genes (July 17 2008)
The MIT Technology Review looks at continued attempts to understand the degree to which present healthy human longevity is influenced by genes: "An ambitious plan to sequence 100 genes in 1,000 healthy old people could shed light on genetic variations that insulate some people from the ailments of aging, including heart disease, cancer, and diabetes, allowing them to live a healthy life into their eighties and beyond. Rather than focusing on genetic variations that increase risk for disease, scientists plan to focus on genes that have previously been linked to health and longevity. ... advances in genetic screening technologies have allowed scientists to start searching the genome for clues to healthy aging and a lengthy life span. That work has revealed that the genomes of healthy old people are not blemish free. ... These people have genetic susceptibility markers for many serious diseases [but] they don't get any of these diseases. What is the explanation? What might account for their insulation from these diseases?" Genes are not fate - evidence to date suggests that lifestyle choices have much more weight for all but the most genetically unlucky, and those choices are reflected in epigenetic variations, not genetic variations.
Self-Assembly In Tissue Engineering (July 16 2008)
The MIT Technology Review looks at a promising strategy in tissue engineering: "Tissue engineers are ambitious. If they had their way, a dialysis patient could receive a new kidney made in the lab from his own cells, instead of waiting for a donor organ that his immune system might reject. Likewise, a diabetic could, with grafts of lab-made pancreatic tissue, be given the ability to make insulin again. But tissue engineering has stalled in part because bioengineers haven't been able to replicate the structural complexity of human tissues. Now researchers have taken an important first step toward building complex tissues from the bottom up by creating what they call living Legos. These building blocks, biofriendly gels of various shapes studded with cells, can self-assemble into complex structures resembling those found in tissues. ... This will be an effective way to put the cells where we want them to be. You can probably generate a tissue with a higher complexity [using] the new method than is possible with a scaffold that has to be seeded with cells." Compare and contrast with the use of whole-organ cell matrix templates, another recent development aimed at solving the same problem.
Stress, Cortisol, and Shortened Telomeres (July 16 2008)
Chronic stress correlates with shorter telomeres, as well as with worse health. Via EurekAlert! researchers are proposing a mechanism by which telomere length is reduced by stress, leading to a worse immune response: "Short telomeres are linked to a range of human diseases, including HIV, osteoporosis, heart disease and aging. ... an enzyme [called telomerase] keeps immune cells young by preserving their telomere length and ability to continue dividing. ... the stress hormone cortisol suppresses immune cells' ability to activate their telomerase. This may explain why the cells of persons under chronic stress have shorter telomeres. ... When the body is under stress, it boosts production of cortisol to support a 'fight or flight' response. If the hormone remains elevated in the bloodstream for long periods of time, though, it wears down the immune system. We are testing therapeutic ways of enhancing telomerase levels to help the immune system ward off cortisol's effect. If we're successful, one day a pill may exist to strengthen the immune system's ability to weather chronic emotional stress."
The Foremost Target of Regenerative Medicine (July 15 2008)
Here's another Future Current transcript of biomedical gerontologist Aubrey de Grey at Aging 2008: "Aging is bad for you. It is a degenerative condition, and thus a theoretical target of regenerative medicine. What I have come here today to tell you, and what my scientific colleagues will be telling you over the next hour or so, is that it is no longer simply a theoretical target of regenerative medicine. It is on its way to becoming a practical one. Why is that? Really it comes down to this definition of aging that I have written down. This is something that gerontologists and people who study the biology of aging have known for a very long time, but it has not always been stated quite so explicitly. Aging is very definitely a side effect of being alive in the first place. You accumulate various types of damage, just in the same way that a simple man-made machine like a car will accumulate damage as a side effect of its normal operation. Again, just like man-made machines, the human body can tolerate that damage with more or less no loss of function or performance for a very long time. The damage only starts to really matter when it reaches a threshold of abundance that is prejudicial to the optimal performance of metabolism."
Why Fight Aging? (July 15 2008)
A Future Current transcript of one of Aubrey de Grey's presentations at Aging 2008: "Some people say, 'I don't want to live to a thousand.' I don't want to live to a thousand, necessarily. I don't even know if I want to live to a hundred. But I do know I want to make that choice when I am 99, rather than having it gradually removed from me by declining health. This is what it comes down to. The extension of lifespan by the defeat of aging is not the point - at least it is not the main point for me, and I do not think it is the main point for most people who are engaged in this crusade. The purpose is to alleviate the suffering that goes with getting decrepit, frail and dependent. Of course, this includes not just those who are suffering that, but the suffering of their loved ones. The extension of average lifespan is essentially a side benefit. It is something that will happen because the way that we are going to do this, using regenerative medicine, will also mean that you have only the same probability you did when you were a young adult of dying peacefully in your sleep without any of these diseases. In other words, a very low probability indeed. You will indeed on average live a great deal longer, and I don't think you’ll complain if you do. However, that is not the purpose. The purpose is to alleviate suffering."
New Heights In Nonsense (July 14 2008)
I've seen a lot of nonsensical, willfully obtuse objections to living a longer, healthier life through technology in the past five years. I think this Wall Street Journal piece tops them all, however. "As for recurrent rejuvenation [it] it fares poorly in a comparison with reincarnation, its closest analogue. According to a basic Hindu understanding, reincarnation involves a succession of new bodies - human, perhaps, but also animal or insect - for the same soul, one that has not yet improved sufficiently to break out of the cycle of life and death and enter the realm of enlightenment. Recurrent rejuvenation, though [keeps] the same body in a continuous loop from youth to age and back again, while the mind is free to accumulate and store all its successive experiences. So a question: Wouldn't [you] be a bit of a wreck after the preserved pain (physical and psychological) of having lived so many years and gone through the aging process 10 or 20 times? A soul in the Hindu reincarnation cycle might not have attained Nirvana, but at least the bad karma carried over from one life can be expunged in the next." Some people are just never going to get it - which is fine, a choice on their part. It's somewhat saddening to see so many slow and painful suicides in the making, however, when compared to the alternative of enhanced healthy longevity that researchers are working towards.
On the Way to Longevity (July 14 2008)
The Daily Bruin talks to some of the folk who were at Aging 2008: "Defeating the effects of time by finding a cure for aging has become the focus of multiple areas of research, bringing the possibilities of achieving immortality from fantasy into the realm of science. The new possibilities offered by regenerative medicine illustrate how advancements in therapy on the molecular and cellular level may be able to extend the healthy human life span within the next 20 years ... Finding a cure for aging is no longer a theoretical target or a fantasy, but on the way to becoming a practical target. Aging is the most universal degenerative condition and is now becoming the target of regenerative medicine ... The body is a really complicated machine, but it's still a machine, so its healthy lifespan can be extended indefinitely by sufficiently comprehensive repair and maintenance, just like simple man-made machines. ... Aging is a complex phenomenon that affects many different systems ... understanding it and fixing the damage as it comes can potentially cure the harmful effects of aging and as a result, elongate the healthy human lifespan."