A Null Result for Vigorous Exercise and Telomere Length
Telomeres are the caps at the ends of chromosomes, shortening with each cell division in normal cells. When very short a cell self-destructs or falls into a senescent state and ceases further replication. Stem cells maintain long telomeres via the activity of telomerase, and provide fresh new long-telomere daughter cells to replace those lost over time in tissues throughout the body. Average telomere length in a cell sample is thus a reflection of stem cell activity and consequent cell replacement rates, as well as the pace of cell division. It is commonly measured in immune cells from a blood sample, and tends to fall during periods of ill health and be lower for older people. This should not be surprising given that stem cell activity declines with age, one of the contributing causes of frailty and failure of tissue function.
There are considerable limitations inherent in the interpretation of present telomere length measurement techniques, not least of which being the existence of studies such as this one in which study populations known to have longer life expectancies and better health do not demonstrate longer telomere length. It isn't hard to find work that challenges the relevance of this marker as a tool for everyday clinical medicine, or even as a basis for serious studies in aging, at least as presently measured:
A career as an elite-class male athlete seems to improve metabolic heath in later life and is also associated with longer life expectancy. Telomere length is a biomarker of biological cellular ageing and could thus predict morbidity and mortality. The main aim of this study was to assess the association between vigorous elite-class physical activity during young adulthood on later life leukocyte telomere length (LTL). The study participants consist of former male Finnish elite athletes (n = 392) and their age-matched controls (n = 207).Relative telomere length was determined from peripheral blood leukocytes by quantitative real-time polymerase chain reaction. Volume of leisure-time physical activity (LTPA) was self-reported and expressed in metabolic equivalent hours. No significant difference in mean age-adjusted LTL in late life was observed when comparing former male elite athletes and their age-matched controls. Current volume of LTPA had no marked influence on mean age-adjusted LTL. LTL was inversely associated with age. Our study findings suggest that a former elite athlete career is not associated with LTL later in life.
Not that they're directly related, but what do you think this means for potential telomerase therapies? I know some people are high on the idea, but others not so much, especially with examples like Reason suggested where the population tested is longer lived and healthier, but don't demonstrate longer telomere length.
Exercise isnt going to lengthen Telomeres drastically and it isnt the replicative clock that is as important as the TPE effect Telomeres have and their control of Gene regulation. Have a read of Wright and Shays papers on the Telomere positioning effect and the papers by Michael Fossel on the matter to make an informed choice.
Telomeres do not cause aging but they are a possible point of intervention on aging. This is not the SENS way but it is going to be tested regardless as Telocyte will go to the FDA sooner or later as it has the funding.
I could cite many studies which show increased organ, tissue and cell function and life extension in animals but the bottom line is we will find out soon enough. Have a read up Ham and see if you agree with Dr Fossel and others about Telomeres or if you think SENS has all the answers.
For my 2 cents I don't care who runs the race to solve aging as long as someone does it, I also don't believe any single group has all the answers and that first pass therapies will likely be an amalgam of approaches.
I do believe however that Gene therapy is ready to deliver some of those first pass therapies and Telocyte, Bioviva and some others have the technology in place to start interventions now. I see gene therapy and later CRISPR as being able to deliver the most elegant solutions over small molecule approaches. We want to be free of relying on drugs as much as possible.
Steve,
I see that our beloved government just stopped allowing gene therapy (which I assume put CRISPR in same category)from happening, at least for now. Just like Bush did for stem cells in the early 2000's.
I hope and assume others around the world will continue working on gene therapy, though.
I want to believe it it can have a somewhat meaningful effect on aging. I've read through some of the stuff, and it seems legit to me (layman on the internet, constantly trying to become more and more educated about all of this), but you're right... we have to wait and see. I wish there was a real biomarker of aging that would actually be able to show effectiveness of treatments. Telocyte looks interesting, and I hope it progresses well enough in order to get the IND, and ultimately progress to human trials.
I'm with you in the sense that I don't care who solves aging, or how they do it. I'm sure the first wave of treatments will be piecemeal of various approaches, until one comprehensive suite is developed. I've thought for a while that life extension won't come all as once, and it'll be a bridge to bridge thing, at least initially. My biggest concern for all of this are the regulation bodies, and having to rely on medical tourism... but that's something to worry about when the time comes.
I'm very interested in the gene therapy approach over traditional drugs, especially as the field gets more and more mature. Unfortunately, the few regulated gene therapies out there tend to be expensive (Glybera is ~1.4 million USD but it's for a very rare disease, so it makes me wonder what something for aging would cost given the widespread appeal), but hopefully as they become more commonplace they will drop in price enough...
@Robert
Where did you see this? I haven't seen any news about stopping gene therapy, outside of germline editing, which wouldn't effect us anyway. I'm from the US, but I didn't see any real UK news on stopping gene therapy there either.
Sorry, Robert, but which governmnt are you talking about?
US Government
Okay, I'm gonna need a source on that, because something like "US Government outlaws gene therapy" would be all over the news- which it's not.
Robert, would you please elaborate, preferably with a source? There are various scientists and bioethicists calling for a moratorium on use of CRISPR in humans in vivo, and especially germline modifications — but (a) it's just a call for such — no action has taken place; (b) they're proposing an Asilomar-like self-enforced pause, not a government action; and (b) the moratorium on use of recombinant DNA technology was voluntarily lifted within a few years.
It's a moratorium on editing the germline only, this does not effect the tert therapy as its not germline. telocyte and other projects are unaffected by this.
I spent some time tonight locating the article on restrictions of gene therapy and could not find it. But I did find something that may be related.
The title is
"Congressional action needed to optimize regulation of genomic tests" taken from Science Daily date May 27.
Still I remember congress reacting in a news article about the same day with restrictions and me thinking about how it could impede progress in the U.S.
If I come across something more direct I will let you all know.
I think the mooted ban is on genetic modification of embryos until the risks are worked out (and not just medical ones, I think there is only political downside for any politician to appear to be fiddling if something does go wrong).
Anyway pre implantation genetic analysis can and is already used to select embryos free from harmful alleles. So unless you want to add in some allele not possesed by either parent using CRISPR on human embryos has little value at present. This is not comparable to the Bush administrations silly ban on embryonic stem cell research due to religious views on when a human life actually begins.
It isnt a ban on CRISPR or gene therapy its a vote to agree a temporary halt to editing the Germline using that technology until protocals can be agreed internationally.
It does not prevent gene therapy that targets non germline cells therefore it isnt going to change the situation for Telocyte, Bioviva and the other companies working on gene therapy for aging.
This isnt going to change development of gene therapy as an aging intervention and it wont stop work on CRISPR for long either so I am not concerned about it at all. If anything public attention will be drawn to the potential of CRISPR and hopefully in a positive way at that.
Good blogs/web sites to read about same subject or related are:
1. George Church's lab:
http://arep.med.harvard.edu/gmc/news.html
2. prof. Paul Knopfler from UC Davis:
http://www.ipscell.com/
3. Dr Emmanuelle Charpentier's company:
http://crisprtx.com/
4. Jennifer Doudna Lab:
http://rna.berkeley.edu/index.html
Steve, thanks your thoughts. Also, Jim, I appreciate you weighing in as well. And, Adrian, for your links.
Yes, my first reaction was that it would have the same results as Bush's ban on embryo stem cells.
I think Gene Therapy and CRISPR will really help transform the medical field and many people, and quickly.