
Scott Kelly's DNA shows unexpected telomere lengthening after year in space - ramzyo
http://www.nature.com/news/astronaut-twin-study-hints-at-stress-of-space-travel-1.21380
======
probe
From what I've heard/read telomere length as the anti-aging curing may be a
bit overrated, because we actually want to prevent cognitive degeneration (who
cares if you live longer if you can't think as well). There's a very
interesting ongoing study called the Lothian Birth Cohort Study, where they
tested cognitive functioning in 11 year olds born in Edinburgh in the years
1921 and 1936. In the late 1990s/early 2000s the individuals were tracked down
(now in their 70-80s) and researchers did extensive, extensive testing to try
to explain variances in cognitive functioning between their scores at age 11
and now (why did some people lose ability/others gain?)

I talked to the director of this massive study and he said there was no
correlation with cognitive functioning and telomere length [1] and the entire
thing may be a bit overrated. Interestingly enough though, he said there there
was a strong correlation with DNA methylation[2] with increased methylation
associated with worse cognitive aging.

Very interestingly, DNA methylation decreased for Scott after his time in
space...

[1]
[https://www.ncbi.nlm.nih.gov/pubmed/21194798](https://www.ncbi.nlm.nih.gov/pubmed/21194798)
[2] [https://www.ncbi.nlm.nih.gov/projects/gap/cgi-
bin/study.cgi?...](https://www.ncbi.nlm.nih.gov/projects/gap/cgi-
bin/study.cgi?study_id=phs000821.v1.p1)

~~~
Dan_Nguyen
Regarding longevity, it's also worth noting that telomere shortening are a
very effective anti cancer mechanism.

Cancer is the runway division of cells. Preventing cell division when the
telomeres are too short ensures there is a finite number of times a cell can
divide, meaning there is a finite number of times a cancer cell can divide.
This helps prevent cancer from dividing indefinitely. Especially in older
folks, we see how terrible cancer can be when those cells mutate and can
regenerate telomere length, giving themselves unlimited division.

It's the physical trade-off we have with lengthening or preserving telomere
length. They give _all_ of our cells more divisions, good and bad. Since
cancer is an exercise in the law of large numbers (how many random mutations
will it take for it to hit a critical point in your DNA?), Longer lifespans
with longer telomeres will inevitable also mean more aggressive cancers.

------
wodencafe
Scott and Mark are great. Interesting note:

"Once Scott returned to the ground, the length of his telomeres returned to
his pre-flight levels relatively quickly. "

~~~
swsieber
So if my intuition is applicable (which it's probably not)- it's longer
because it stretches out, not because it's accumulating material? I assume
that's not really possible though...

~~~
daemonk
Telomere length is not measured by physical length. It is measured by the
actual number of repeats of the sequence.

~~~
philsnow
well, isn't the telomere sequence just some sequence of base pairs, and all
base pairs are the same length ?

from
[https://en.wikipedia.org/wiki/Base_pair](https://en.wikipedia.org/wiki/Base_pair)
:

> one bp corresponds to approximately 3.4 Å (340 pm) of length along the
> strand

so physical length and number of repeats of the sequence are the same, by some
factor.

~~~
daemonk
Sure. But the question assumed that the physical length can be variable
depending on the environment. Even if that was the case, measurement of
telomeres by the sequence themselves will be independent of environmental
factor.

Maybe this is not the perfect analogy, but the character 'a' and the character
'A' might have different heights, but they still represent the same letter of
the alphabet.

------
cixin
Off the top of my head: I wonder if astronauts are on lower calorie diets than
usual.

Lowering calorie intake is one of the few well known ways that lifespan can be
increased. Will have to see if there's any research correlating low calorie
diets and telomere length.

~~~
candiodari
There is also one sure-fire way to increase telomere length : get cancer.

So these people were in a thin metal cube, exposed to abnormal levels of
ionizing radiation, ... and after that there was telomere lengthening ? I
always heard that astronauts, given the groups they're selected from, have
suspiciously short lifespans. Still somewhat above average, but these guys got
selected from the creme de la creme. Half of them should live to 120, and that
is definitely not happening. I've never seen a good study actually comparing
it though.

[http://dailycaller.com/2016/02/06/apollo-14-astronaut-
dies-o...](http://dailycaller.com/2016/02/06/apollo-14-astronaut-dies-
only-7-moonwalkers-still-alive/)

According to several doctor friends of mine, balance is the best way to go for
a long life. Being too thin will kill you, because once you're 65 or 70 or so
you will lose the ability to quickly gain weight. A significant number of
people dying from "natural causes" die as follows : they get infected with
something stupid, like a flu virus. Or they break a hip or something. Either
way, they get really under the weather. Result: they lose weight, a lot of
weight, rapidly. If your weight falls under about 35 kg, odds of survival drop
dramatically, and they die from "complications" (in practice: secondary
infections resulting in metabolic exhaustion: your body simply cannot maintain
the minimum energy level to keep you alive. On the plus side: very peaceful
way to go, and likely quite comfortable too). Keep in mind it will take a year
to work your way back from 40kg to 50kg at such an age, so the higher you go
the more likely you'll drop back down due to another incident before
recovering.

And of course, exercise only helps up to a normal level. If you spend 2 hours
every day running, that is definitely in the "shortens lifespan" area. 10
minutes, probably very good for you. And of course, the obvious : exercise
increases the odds of accidents happening. Accidents, even stupid ones, can
kill.

~~~
talklittle
> _There is also one sure-fire way to increase telomere length : get cancer._

This badly needs a source.

This article from 2013 [1] says the opposite, that shorter telomeres are
associated with cancer:

 _In recent years, shorter telomeres have become associated with a broad range
of aging-related diseases, including many forms of cancer, stroke, vascular
dementia, cardiovascular disease, obesity, osteoporosis and diabetes._

And another [2]:

 _" Telomere shortening is common in cancer, but the degree of shortening
varies from one cancer cell to another within each patient, and this
variability may give us a better idea of how prostate cancers behave."_

[1]: [https://www.ucsf.edu/news/2013/09/108886/lifestyle-
changes-m...](https://www.ucsf.edu/news/2013/09/108886/lifestyle-changes-may-
lengthen-telomeres-measure-cell-aging)

[2]:
[http://www.hopkinsmedicine.org/news/media/releases/in_prosta...](http://www.hopkinsmedicine.org/news/media/releases/in_prostate_cancer_prognosis_telomere_length_may_matter)

~~~
pragone
Edit: At the top since I think it may qualify my comments: I think there's a
causation/correlation incongruity in this, the parent, and the grandparent
posts. Telomere lengthening can lead to cancer; getting cancer is not
necessarily a "sure-fire way to increase telomere length"

"Cancer" is an unbelievably broad term. Generally speaking, expression of
telomerase and maintenance of telomeres is seen in (many) cancers. The
background behind this is that as telomeres shorten with each cell
replication, they get to a point where they are too short, and the cell stops
dividing. Cancer occurs when cells that are not supposed to divide keep
dividing.

------
teabee89
This would bring another reason for the billionaire in the 1997 movie Contact,
to go to space to live just a little longer :P

~~~
blacksmith_tb
A bit more like Elysium[1], I'd say...

1:
[https://en.wikipedia.org/wiki/Elysium_(film)](https://en.wikipedia.org/wiki/Elysium_\(film\))

That said, being exposed to a lot of high-energy ionizing radiation and
lengthening one's teleomeres doesn't sound like a good combination...

~~~
teraflop
In Elysium, living in space wasn't directly connected to a longer lifespan. It
just so happened that the elite segment of the population was able to afford
both.

Arthur C. Clarke's short story "The Secret" is a bit more directly relevant:
[https://en.wikipedia.org/wiki/The_Secret_(short_story)](https://en.wikipedia.org/wiki/The_Secret_\(short_story\))

------
didgeoridoo
Surprised the article didn't bring up radiation hormesis as a plausible
explanation. Maybe I'm misunderstanding the observed effects?

~~~
manarth
The NASA article [1] gives a little more background, and offers another
explanation:

    
    
      Bailey found Scott’s telomeres on the ends of chromosomes in his
      white blood cells increased in length while in space.
      
      This could be linked to increased exercise and reduced caloric
      intake during the mission.
    
    

[1] [https://www.nasa.gov/feature/how-stressful-will-a-trip-to-
ma...](https://www.nasa.gov/feature/how-stressful-will-a-trip-to-mars-be-on-
the-human-body-we-now-have-a-peek-into-what-the-nasa)

------
devy
I have no idea what the significance of telomere is (googled it but really
want a TL;DR version). Can someone explain this preliminary result in layman's
terms?

~~~
nolok
Telomeres protect your DNA from degeneration during cell division. As you age,
your telomeres get shorter and shorter, and ultimately lead to cell division
not producing viable cells anymore.

Quoting wikipedia:

> During chromosome replication, the enzymes that duplicate DNA cannot
> continue their duplication all the way to the end of a chromosome, so in
> each duplication the end of the chromosome is shortened [...] The telomeres
> are disposable buffers at the ends of chromosomes which are truncated during
> cell division; their presence protects the genes before them on the
> chromosome from being truncated instead.

> Telomere shortening is associated with aging, mortality and aging-related
> diseases. In 2003, Richard Cawthon discovered that those with longer
> telomeres lead longer lives than those with short telomeres. However, it is
> not known whether short telomeres are just a sign of cellular age or
> actually contribute to the aging process.

~~~
mysterypie
> As you age, your telomeres get shorter

The human body has a mechanism to reset telomere length during reproduction;
i.e., babies are born with "full length" telomeres.

Can anyone shed light on why this mechanism is so hard to trigger in an adult?
What are the technical difficulties in artifically lengthening telomeres?

~~~
svachalek
I'm no biologist, but from what I understand the body actually does maintain
telomeres over time, it just doesn't keep up with the loss from cell division
over a lifetime.

Purely speculating, death to "old age" is rare in nature so the process merely
has to be "good enough" for our genes to compete rather than perfect enough
for immortality.

------
ohitsdom
Interesting results. But were twins needed for this discovery? I would imagine
the the telomere length change could have been discovered by pre-mission, in-
mission, and post-mission sampling. I'm guessing this was discovered in this
study because of the in-depth DNA sampling, not due to having a twin to
compare to.

~~~
godelski
The twins were used because they are doing a wide variety of genomic testing.
One serves as a baseline. So twins will give a low variance between
candidates.

------
zherbert
Maybe we will determine in the distant future that aging is related to
gravity? :)

~~~
metamet
I'm excited to ask Mazer Rackham when he returns.

------
api
Could it be radiation hormesis?

------
dsmithatx
Could this be as simple as, gravity has an effect on telomeres length?

------
sctb
Yesterday's discussion:
[https://news.ycombinator.com/item?id=13530595](https://news.ycombinator.com/item?id=13530595)

~~~
ramzyo
As the original submitter: it seems like this post, although a duplicate, was
generating further engaging and informative discussion beyond that discussed
in the previous post, arguably more than the previous post (on the basis of
number of comments within the first hour being equivalent to number of
comments over the course of the 24 hour lifetime of the previous post). Not
sure if this was you, but marking as duplicate has effectively killed that
discussion by making the post disappear.

As the HN policy around reposts is somewhat subjective "If a story has had
significant attention in the last year or so, we kill reposts as duplicates.
If not, a small number of reposts is ok," I'd contend that marking as dupe in
this case wasn't the right move. While the post from yesterday did get
significant attention, that post moved past the front page, and today's repost
resulted in meaningful and engaging further discussion. Unfortunately now that
discussion is most probably dead, as is the discussion on yesterday's post,
where new comment activity has stalled.

~~~
ramzyo
Furthermore, my intent with this submission was to highlight a specific
finding of the research that is not the emphasis of the previous post (namely,
the unexpected result involving telomere length). The discussion on this post
generally focused on that result, whereas the discussion on the previous post
did not.

~~~
sctb
OK, we've unmarked this one as a dupe and restored it.

