Preventing reproduction can extend lifespan in mammals across a wide range of species, a new study has found.
A major international study led by the University of Otago has found that blocking reproduction increases lifespan in both males and females across a wide range of species.
Lead author Associate Professor Mike Garratt, of Otago’s School of Biomedical Sciences, joined the Afternoons team to discuss.
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Speaker 1 (00:09):
You're listening to a podcast from news Talk ZEDB. Follow
this and our wide range of podcasts now on iHeartRadio.
Speaker 2 (00:17):
So this is fascinating. A University of a Targo study
found that sterilization boosts life span across one hundred and
seventeen species. The major international study has found that blocking
reproduction increases lifespan in both males and females across that
wide range of species. The lead author is Associate Professor
Mike Garrett of A. Targo's School of Biomedical Sciences, and
(00:38):
he joins us on the phone. Now, very good afternoon
to you.
Speaker 3 (00:41):
Mike, Hi, how's it going good?
Speaker 1 (00:44):
Thanks?
Speaker 4 (00:44):
Could you explain to me, like I'm an idiot, why
stopping reproduction makes animals live longer?
Speaker 3 (00:51):
Well, reproduction is costly. It has energetic costs, for example,
and when we inhibit those, it can help animals invest
in other processes, for example looking after their immune system,
and this can improve survival.
Speaker 4 (01:05):
Could it be a risky behavior thing? Because you know
when the you know on that is that it reduces
risky behavior rather than some sort of deep biological aging effeete.
Speaker 3 (01:18):
So there are a couple of different things that we
show in this article. In the context of males, we
show that castration extends lifespan and in part, yes, part
of the reason they live longer is they're less likely
to engage in risky behaviors. Although in other contexts where
we've looked at a sect of castration, for example, in
lab animals, you also see improvement in improvement in other
(01:40):
aspects of health. So yes, in part, it can improve
survival because it reduces investment in risky behaviors, but it
also provides other benefits late in life as well, at
least in the animals that have been that's been studied.
Speaker 4 (01:54):
And how long a life span gain is that we're
talking what teen twenty percent? How long is it?
Speaker 3 (01:59):
Yeah, across the studies, across the species that we looked,
so you know, we looked at over one hundred different species,
we found an average increase in life span of about
ten percent. Those effects were stronger in partigure in the
context of castration if animals were castrated early in life,
before they went through puberty. So in those contexts we
found an average increase in lifespan that was greater, more
(02:20):
like fifteen to twenty percent, depending on the species.
Speaker 4 (02:23):
Now I was thinking about this when I was walking
my dog Colin the other day, and you know, he's
he's castrated, and he seems pretty pretty happy in his life.
But part of me feels a bit said because you know,
that's the end of his line and he's such a
great dog. But it made me think as well, is
he happier because he has been fixed, or is he
(02:44):
still part of them that feels like he's missing out
on something you know, deep in his you know instincts.
Speaker 3 (02:52):
Well, it's an interesting question, I think if we're talking
about so you seem to be focusing on the castration
component here. You know, once you're castrated, you don't have
the same drive to reproduce. So actually you probably are
happier if you're not castrated, but you're kept in an
environment where you can't reproduce. Yeah, that could also be stressful.
So actually, in that situation, you know, you might have
(03:13):
be exposed to androgens. You've got this drive to reproduce,
but that's not met with the actual reward of mating.
So actually that could potentially be more stressful for the
animal than actually being castrated. And then you don't necessarily
need those reproductive opportunities or you don't want them.
Speaker 4 (03:28):
Now, the obvious question in the Elephant and the Room,
I guess is should I castraight myself? Can you interpret
anything meaningful around humans from the study or is it
a bridge too far?
Speaker 3 (03:39):
Well, in our study, we did try to extrapolate some
of our results to humans. There've been a couple of
studies that have been conducted on historical data sets where
people have been castrated for various different reasons. There was
a study on Korean unix from I think that the
seventeenth eighteenth century. That data has been quite controversial. But
(03:59):
the mean increase in life as you would expect, but
the mean increase in lifespan that was reported in those
studies actually matches what we report in after so you know,
it's potential that these benefits might extend to humans. However,
we also find in our study that the effects of
sterilization and castration are stronger when you keep animals in
wild environments where they have to, you know, invest heavily
(04:23):
in different things. We don't have as many resources, right,
so I think actually the society that we're living means
that probably we wouldn't necessarily get those benefits because we
have really good healthcare. You know, we're largely protected from
infectious disease. You know, we aren't exposed to the same
level of mortality from risky behavior, from aggression, from things
like that. So yeah, so don't go out and castrate yourself.
(04:45):
Very interesting.
Speaker 4 (04:46):
I was sitting on the fience but ye, leaving things things, Mike.
Speaker 2 (04:50):
So when you look at vasikamese, Mike, it's obviously different
to castration, and according to the study there, there wasn't
those same finding. So any human out there right now
that's head of the seek to me and hoping to
live a bit longer, it might not be that they're simple.
Speaker 3 (05:06):
Yes, that's right. So there's there's little data available in
animals and definitely little experimental data. So the two in zoos,
and a lot of our analysis has conducted on zoo
house species, so we were able to look retrospectively at
zoo records. Now there are only a couple of species
where they routinely do vasectomy rather castration. That's lions, because
they want to maintain the lion's main and if you
(05:28):
castrate then that goes away. Also, baboons, you know, they
have this big kind of secondary sexual coloration, so to
use theseectomy in those contexts, and in those contexts we
see no effects on survival. There've also been a couple
of laboratory studies of laboratory life and there they also
see no effect on survival. So evidence would suggest that
it needs to be castration in the context of males.
Speaker 4 (05:49):
And what do you see me and what do you see?
As a nixt big question, this research opens up what's
the practical implications for this?
Speaker 3 (05:59):
Well, I mean, we'd really like to understand the effects
on the biology of aging, So what's actually happening, How
does this occur? In particular, we found that the effects
of castration are stronger when they're cur before puberty, So
there's something that must occur through puberty where testosterone has
effects on the body. It potentially helps you to show
kind of male specific growth, male specific behavior, but then
(06:20):
reduces lifespan. And trying to understand the mechanisms of that,
you know, how they interact with other pathways that influence aging.
Other hormones might ultimately allow us to understand the aging
process aging process better and you might be able to
get the benefits of those things without castration.
Speaker 2 (06:37):
Interesting, so how would you do that? You know, This
is hYP thetical, of course, but potentially talking about after
that puberty period some sort of medication to balance out
testosterone levels to allow people to live a bit longer.
Speaker 3 (06:50):
So I mean, I could try and go into a
little bit of detail with you, but there are other parts.
So we've said in our study that androgen's testosterone influences
aging in males. There are other pathways that we also
know influence lifespan in animals. There's some other hormones like
growth hormone and some some proteins in cells that also
(07:10):
influence the aging process while at the same time helping
you grow. So there are other hormones that make you grow,
but I make you have a short live span. We
know that, so androgens probably feed in to that pathway.
How it influences cells influence aspects of stress resistance, but
also influence aspects of growth, and we can try to
understand those trade offs, those actual mechanisms, those things that
(07:34):
go on in cells that mean that the cells grow
but they're less protected against stress, if that makes sense
to mean, can really just try and delve into the
actual mechanisms at the level of a cell.
Speaker 4 (07:45):
It's an interesting one because I would say that my
kids have definitely aged me with worry, but they've also
added a lot of meaning and happiness to my life.
So I would say having my children, I may die earlier,
but my overall happiness well has been increased by them.
So they've definitely a trade off from a human bespeaktive,
isn't it well?
Speaker 3 (08:05):
I mean, how old are your children at the moment?
Minor four and six and they're definitely aging. It's not
it doesn't feel it quite as worthwhile at the moment.
Speaker 4 (08:15):
Well, teenagers and it's moved into the pure happiness stage
at this point.
Speaker 3 (08:21):
I'll hold you for that.
Speaker 2 (08:24):
Yeah, Mike, you've been brilliant. Thank you very much for
joining us and having a chat. It's fascinating research and
we're interested to see where it goes.
Speaker 3 (08:33):
Nice to speak to you, that is.
Speaker 2 (08:34):
Associate Professor Mike Garrett out of the Otago University. Fascinating stuff.
Speaker 1 (08:40):
For more from News Talks B listen live on air
or online, and keep our shows with you wherever you
go with our podcast on iHeartRadio.
You're listening to a podcast from news Talk ZEDB. Follow
this and our wide range of podcasts now on iHeartRadio.
Speaker 2 (00:17):
So this is fascinating. A University of a Targo study
found that sterilization boosts life span across one hundred and
seventeen species. The major international study has found that blocking
reproduction increases lifespan in both males and females across that
wide range of species. The lead author is Associate Professor
Mike Garrett of A. Targo's School of Biomedical Sciences, and
(00:38):
he joins us on the phone. Now, very good afternoon
to you.
Speaker 3 (00:41):
Mike, Hi, how's it going good?
Speaker 1 (00:44):
Thanks?
Speaker 4 (00:44):
Could you explain to me, like I'm an idiot, why
stopping reproduction makes animals live longer?
Speaker 3 (00:51):
Well, reproduction is costly. It has energetic costs, for example,
and when we inhibit those, it can help animals invest
in other processes, for example looking after their immune system,
and this can improve survival.
Speaker 4 (01:05):
Could it be a risky behavior thing? Because you know
when the you know on that is that it reduces
risky behavior rather than some sort of deep biological aging effeete.
Speaker 3 (01:18):
So there are a couple of different things that we
show in this article. In the context of males, we
show that castration extends lifespan and in part, yes, part
of the reason they live longer is they're less likely
to engage in risky behaviors. Although in other contexts where
we've looked at a sect of castration, for example, in
lab animals, you also see improvement in improvement in other
(01:40):
aspects of health. So yes, in part, it can improve
survival because it reduces investment in risky behaviors, but it
also provides other benefits late in life as well, at
least in the animals that have been that's been studied.
Speaker 4 (01:54):
And how long a life span gain is that we're
talking what teen twenty percent? How long is it?
Speaker 3 (01:59):
Yeah, across the studies, across the species that we looked,
so you know, we looked at over one hundred different species,
we found an average increase in life span of about
ten percent. Those effects were stronger in partigure in the
context of castration if animals were castrated early in life,
before they went through puberty. So in those contexts we
found an average increase in lifespan that was greater, more
(02:20):
like fifteen to twenty percent, depending on the species.
Speaker 4 (02:23):
Now I was thinking about this when I was walking
my dog Colin the other day, and you know, he's
he's castrated, and he seems pretty pretty happy in his life.
But part of me feels a bit said because you know,
that's the end of his line and he's such a
great dog. But it made me think as well, is
he happier because he has been fixed, or is he
(02:44):
still part of them that feels like he's missing out
on something you know, deep in his you know instincts.
Speaker 3 (02:52):
Well, it's an interesting question, I think if we're talking
about so you seem to be focusing on the castration
component here. You know, once you're castrated, you don't have
the same drive to reproduce. So actually you probably are
happier if you're not castrated, but you're kept in an
environment where you can't reproduce. Yeah, that could also be stressful.
So actually, in that situation, you know, you might have
(03:13):
be exposed to androgens. You've got this drive to reproduce,
but that's not met with the actual reward of mating.
So actually that could potentially be more stressful for the
animal than actually being castrated. And then you don't necessarily
need those reproductive opportunities or you don't want them.
Speaker 4 (03:28):
Now, the obvious question in the Elephant and the Room,
I guess is should I castraight myself? Can you interpret
anything meaningful around humans from the study or is it
a bridge too far?
Speaker 3 (03:39):
Well, in our study, we did try to extrapolate some
of our results to humans. There've been a couple of
studies that have been conducted on historical data sets where
people have been castrated for various different reasons. There was
a study on Korean unix from I think that the
seventeenth eighteenth century. That data has been quite controversial. But
(03:59):
the mean increase in life as you would expect, but
the mean increase in lifespan that was reported in those
studies actually matches what we report in after so you know,
it's potential that these benefits might extend to humans. However,
we also find in our study that the effects of
sterilization and castration are stronger when you keep animals in
wild environments where they have to, you know, invest heavily
(04:23):
in different things. We don't have as many resources, right,
so I think actually the society that we're living means
that probably we wouldn't necessarily get those benefits because we
have really good healthcare. You know, we're largely protected from
infectious disease. You know, we aren't exposed to the same
level of mortality from risky behavior, from aggression, from things
like that. So yeah, so don't go out and castrate yourself.
(04:45):
Very interesting.
Speaker 4 (04:46):
I was sitting on the fience but ye, leaving things things, Mike.
Speaker 2 (04:50):
So when you look at vasikamese, Mike, it's obviously different
to castration, and according to the study there, there wasn't
those same finding. So any human out there right now
that's head of the seek to me and hoping to
live a bit longer, it might not be that they're simple.
Speaker 3 (05:06):
Yes, that's right. So there's there's little data available in
animals and definitely little experimental data. So the two in zoos,
and a lot of our analysis has conducted on zoo
house species, so we were able to look retrospectively at
zoo records. Now there are only a couple of species
where they routinely do vasectomy rather castration. That's lions, because
they want to maintain the lion's main and if you
(05:28):
castrate then that goes away. Also, baboons, you know, they
have this big kind of secondary sexual coloration, so to
use theseectomy in those contexts, and in those contexts we
see no effects on survival. There've also been a couple
of laboratory studies of laboratory life and there they also
see no effect on survival. So evidence would suggest that
it needs to be castration in the context of males.
Speaker 4 (05:49):
And what do you see me and what do you see?
As a nixt big question, this research opens up what's
the practical implications for this?
Speaker 3 (05:59):
Well, I mean, we'd really like to understand the effects
on the biology of aging, So what's actually happening, How
does this occur? In particular, we found that the effects
of castration are stronger when they're cur before puberty, So
there's something that must occur through puberty where testosterone has
effects on the body. It potentially helps you to show
kind of male specific growth, male specific behavior, but then
(06:20):
reduces lifespan. And trying to understand the mechanisms of that,
you know, how they interact with other pathways that influence aging.
Other hormones might ultimately allow us to understand the aging
process aging process better and you might be able to
get the benefits of those things without castration.
Speaker 2 (06:37):
Interesting, so how would you do that? You know, This
is hYP thetical, of course, but potentially talking about after
that puberty period some sort of medication to balance out
testosterone levels to allow people to live a bit longer.
Speaker 3 (06:50):
So I mean, I could try and go into a
little bit of detail with you, but there are other parts.
So we've said in our study that androgen's testosterone influences
aging in males. There are other pathways that we also
know influence lifespan in animals. There's some other hormones like
growth hormone and some some proteins in cells that also
(07:10):
influence the aging process while at the same time helping
you grow. So there are other hormones that make you grow,
but I make you have a short live span. We
know that, so androgens probably feed in to that pathway.
How it influences cells influence aspects of stress resistance, but
also influence aspects of growth, and we can try to
understand those trade offs, those actual mechanisms, those things that
(07:34):
go on in cells that mean that the cells grow
but they're less protected against stress, if that makes sense
to mean, can really just try and delve into the
actual mechanisms at the level of a cell.
Speaker 4 (07:45):
It's an interesting one because I would say that my
kids have definitely aged me with worry, but they've also
added a lot of meaning and happiness to my life.
So I would say having my children, I may die earlier,
but my overall happiness well has been increased by them.
So they've definitely a trade off from a human bespeaktive,
isn't it well?
Speaker 3 (08:05):
I mean, how old are your children at the moment?
Minor four and six and they're definitely aging. It's not
it doesn't feel it quite as worthwhile at the moment.
Speaker 4 (08:15):
Well, teenagers and it's moved into the pure happiness stage
at this point.
Speaker 3 (08:21):
I'll hold you for that.
Speaker 2 (08:24):
Yeah, Mike, you've been brilliant. Thank you very much for
joining us and having a chat. It's fascinating research and
we're interested to see where it goes.
Speaker 3 (08:33):
Nice to speak to you, that is.
Speaker 2 (08:34):
Associate Professor Mike Garrett out of the Otago University. Fascinating stuff.
Speaker 1 (08:40):
For more from News Talks B listen live on air
or online, and keep our shows with you wherever you
go with our podcast on iHeartRadio.
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