The Secret Ingredient in Young Blood: Oxytocin?

Last month, I wrote in the New York Times about a creepy yet potent way to reverse aging. All you have to do is join an old mouse to a young mouse. As the young mouse’s blood flows through the old mouse’s body, it rejuvenates the heart, skeletal muscle, and even the brain.

When scientists saw just how dramatic this reversal could be, they started investigating how it happens. They suspected that it wasn’t blood as a whole that was responsible for the transformation. Blood is a finely blended consommé of cells and free-floating molecules. It was possible that only certain compounds in young blood are required to counter aging. That would be excellent if true, since it would put a damper on any vampire-like strategies for applying this discovery to people. All old people would need to do was take a pill containing the compounds that bring about the change.

As I wrote in my article last month, scientists identified one protein, called GDF11, may help reverse aging in the young blood experiments. But they suspected that more than one molecule would be involved. And today, a team of scientists at the University of California at Berkeley are publishing evidence in favor of a new molecule. What makes this result especially surprising is that this molecule is already fairly famous for other effects on the body. It’s oxytocin.

You may have heard of oxytocin as a love drug, or as a moral molecule. It is certainly true that this hormone, which is produced in the brain, plays some important roles in the social life of mammals. Monogamous voles, for example, appear to depend on oxytocin to strengthen their bonds with their mates. When scientists prevent their cells from taking up oxytocin, the voles become more promiscuous. Likewise, oxytocin plays a part in the mother-child bond. Its concentration rises in women during pregnancy and nursing. If ewes are blocked from taking up oxytocin, they neglect their newborn lambs.

But, as fellow Phenom Ed Yong explained in this 2012 Slate piece, at this point oxytocin should really be called the “hype hormone.” People are way too eager to leap from the existing evidence about oxytocin’s effects to calls for its use as a therapy for children with depression or autism. And as Ed wrote in April in The Scientist, oxytocin also seems to be involved in negative emotions and even lying. Reckless use of oxytocin could have some unwanted effects.

It may seem strange for one little molecule to influence us in so many ways. But that’s true for many hormones. They are signals, but the message they deliver depends on their context. In that respect, hormones are like the words we use to relay messages to each other. Think of the wildly different messages, depending on the context, that just five words can have: “What are you doing here?”

In fact, the effects of oxytocin range far beyond emotions and behaviors. In recent years, for example, scientists have found evidence that oxytocin can reduce osteoporosis and obesity. Oxytocin can relay important signals to cells throughout the body, not just in the brain.

Recently Irina Conboy and her colleagues became intrigued by a few of these experiments. When scientists remove the ovaries from female mice, for example, their levels of oxytocin drop dramatically. The mice also start to age rapidly. Could there be a cause and effect there?

Another clue came from the receptors on the surfaces of cells that can grab oxytocin. The cells with these receptors include stem cells that can produce new muscle. Was it possible that oxytocin sent these cells a signal to develop and renew old muscle?

Clues like these fostered a hunch in the minds of the scientists. Maybe oxytocin was one of the molecules in young blood that could rejuvenate old animals.

As the scientists report in Natural Communications, they ran a series of experiments that strongly suggest that this is indeed the case. They wondered, for example, if naturally aging mice lost oxytocin, in the same way as mice that have their ovaries removed. They found that as mice get old, their oxytocin level drops to a third of the level in young mice. They also found muscle stem cells produce fewer receptors for oxytocin as mice get older.

The scientists then gave oxytocin to old mice. They found that the mice were able to regenerate more new muscle fibers. And when they blocked oxytocin in young mice, the mice couldn’t renew their muscles. In this respect, they became old.

Conboy and her colleagues got a similar result when they engineered mice that could not produce oxytocin. The mice developed normal muscles, but as adults they lost muscle mass much faster than normal mice.

To get a closer look at what oxytocin was doing, the scientists reared muscle stem cells in a dish and added oxytocin to them. Once the cells grabbed onto the hormone, they multiplied quickly. In other words, oxytocin appears to be directly altering the behavior of stem cells, just as the scientists had suspected.

The new study provides a new hypothesis for how we get old. When people are young, they produce lots of oxytocin. On top of whatever psychological effects it may have, that extra oxytocin also tells stem cells to turn into muscle cells, keeping people strong. Young people might also produce GDF11 and other molecules at high levels, and in combination, they may keep all the organs young. And once those signals start to fade in old age, the body starts to fall apart.

Theoretically, giving old people compounds like oxytocin or GDF11 may cause their cells to act young again. The compounds could be the basis for an all-purpose treatment for the diseases of old age, from osteoporosis to heart disease to Alzheimer’s.


It’s worth bearing in mind that all the studies I’m writing about have only been carried out in mice or rats. We can’t say for sure that the effects would carry over into human trials. We don’t even know if oxytocin is high in children and low in old people–not to mention what the “right” level of oxytocin would be to reverse aging.

It’s also worth bearing in mind that there may very well be a good reason that youth-generating signals fade as we get older. If the signals don’t deliver exactly the right message, in exactly the right context, our cells might misinterpret them in a disastrous way. Instead of just multiplying to restore weakened muscles, for example, stem cells might grow uncontrollably, leading to cancer.

But Conboy and her colleagues respond to that concern by pointing out that we already know a lot about oxytocin as a drug in people. Because its other effects have gained so much attention, it’s already been extensively tested. In its synthetic form, pitocin, it’s approved for use in pregnant women who are past term, in order to speed up their labor. Human clinical trials are already underway to try out oxytocin as treatment for psychological disorders. While it’s not free of side-effects, oxytocin has never been linked to cancer in all the testing that it’s undergone.

Of the many messages oxytocin delivers around our bodies, it’s possible that the message to stay youthful is relatively clear. On the other hand, if there’s one thing oxytocin has taught us so far, it’s that hype can’t replace real research.

8 thoughts on “The Secret Ingredient in Young Blood: Oxytocin?

  1. Concern about cancer seems to me a little like the guys convinced that “bond vigilantes” would punish the US for goosing the economy with monetary policy. People are just convinced that people are the way they are because that’s how it’s supposed to be, and any manipulation of aging has to come with terminal side effects.

  2. What a Loom, Carl! Your article “Womb to Womb” and this one “Secret Ingredient Oxytocin” look like perspectives on different sets of threads woven into the same underlying intricate biological pattern.

    I’ll grant that there has been a lot of simplistic hype about oxytocin, however I see plenty of scientific nuggets in the Bing pile for
    +oxytocin +”MHC class”

    Viewing through Darwinistic lenses, I speculate that there could be survival advantages to clustering around people exuding oxytocin (youthful, vibrant) and having a similar or compatible immune system. If your immune system’s strengths and vulnerabilities are aligned with the people around you, then might there be a type of group protection at work as long as you have a way to detect if the people around you are happy and healthy? The flipside would be when one of the pack gets ill in a way that decreases his or her oxytocin levels. That would be like an early warning signal to the group. Over long periods of time would Darwinian processes select for a group behavior that isolates individuals having similar immune systems but who don’t produce sufficient oxytocin? I wonder which pathogens affect oxytocin production the most.

    Regarding your other article, “Womb to Womb” relates that
    “A breeding female and male marmoset are attended to by helpers–usually related females that suppress their own ability to have babies while they assist the breeding female.”

    I’ll bet that has spawned lots of questions in researchers’ minds. My own questions might be flimsy in comparison, but here’s what your writing inspired me to ponder:
    What drives those related females to assist? Do their oxytocin levels in some way depend upon being in proximity to the breeding female during her heightened oxytocin production? Do the assistants hang around and help because as long as the mother marmoset is happy they too are happy? And does an assistant’s oxytocin drop when first pulled from the merry band?
    Another nuance: what is the group’s attitude toward a marmoset helper whose oxytocin suddenly drops in spite of being in close proximity to the mother? Or how does the group deal with a marmoset helper whose oxytocin production is high but independent of group-coordinated levels? (I speculate that such a coordination exists, whether or not it is identifiable at this time.)

    I’m very intrigued by what Ed Yong said (in the Slate 2012 article you pointed out)
    “The “love hormone” fosters trust and generosity in some situations but envy and bias in others, and it can produce opposite effects in different people.”

    Is it feasible that oxytocin’s effects are so hard to pin down because it operates within the context of another variable?

    How about this for a study? Divide a test group into subgroups, then administer oxytocin and sort resulting intra-group interactions according to whether participants experienced trust/generosity or envy/bias. Lastly, screen the subgroups for similarities/differences in MHC or other immune system molecules and compare against the interactions reported. I wonder if any correlations would pop up.

    I very much enjoy your articles and books. Thanks!

    John Beach
    Leander, TX (just outside of Austin)

  3. We have opened a new research of aging by a total different approach, searching explanations from the Matrix/DNA’s formula for natural systems. The human body is a system, aging is a property produced by systems’ identity, so, neither young blood, GDF11 or Oxytocin are the first cause, they are effects. The immediate first cause at biological systems ( mice and human body) is programmed into the DNA, more specifically into DNA’s fundamental unit of information – a lateral horizontal pair of nucleotides. These units of information are a system itself, derived from Matrix/DNA formula coming evolutionarily from the prior system that produced biologicals – this astronomical system. But, for understanding the phenomenon “aging” we need go further in time/space, entering into the real of primordial thermodynamic systems and we arrive finally to the first moment that this phenomenon was manifested at the Universe’s origins: the Matrix/DNA formula in shape of light waves emitted by the Big Bang.

    You choose: or applying the method of reductionism, locating and limiting the knowledge to mice and human bodies, or applying the systemic method trying to understand it globally. I think that the wise researcher should apply both methods.

    Aging is a property of any natural system. There is no complete system without aging. Like the wave of light when arriving at the ultraviolet frequency goes towards the visible frequency, there is no way for stopping it here and turning it eternal at this state. When the light waves evolved into the materialized universal formula for systems, is the force of entropy entering the system at middle-age that causes aging. The secret should be avoiding entropy. But it is programmed into the formula, genetically programed.

    Oxytocin must be an accelerator of aging, due the presence of Oxygen and Nitrogen, two entropic atoms. The explanation that it could reverse aging is very complex, only understood if we see the Matrix/DNA formula: human body is composed by a system ( the body without the brain) and other system ( the brain) which was developed for to be the repository of the system’s identity. So, Oxytocin could accelerating the circuit flow of the body, killing it and recycling it continuously, while the brain continues alive all time – but, this hypothesis is too much complex.
    It would be possible reverse aging of organisms because they are opened systems – the Matrix/DNA fundamental formula is about closed perfect system. But, I think, it would need an intervention at the level of DNA, even nucleotides.
    If you are interested or merely curious how our method works, see this first entrance into this research ( sorry, it is still in Portuguese), at: ( A Batalha Contra o Envelhecimento e Relação com a Oxytocin, pela Fórmula da Matrix/DNA ) . It should be good a discussion between the scientific reductionist method and naturalistic philosophical systemic method.

  4. I think that as science pushes into new frontiers
    it must be accompanied by other disciplines such as philosophy, ethics, etc
    so that we can avoid more technologically created progress traps

    For close to two centuries, the general consensus was that fossil fuels benefit humankind or at least that harmful impacts may not materialize for a long time, giving humans a chance to evolve technologies to solve whatever problems they may have created

    We were wrong about that
    as we were wrong about a host of scientific discoveries that have been commercialized and globally scaled

    We have multidisciplinary oversight in many technology fields today
    but the continual pressure of short termism attitudes continue to undermine a holistic approach to technological advancement

    With respect to aging
    it is natural that we don’t want to die
    Survival instinct is programmed into life
    yet as human beings, we are caught in an existential dilemma
    Our consciousness allows us to become aware of our own mortality
    at the same time that the survival instinct is alive within us
    This is the perennial human condition, the paradox of life

    Yet for all the activity that moves in the direction of saving and preserving life
    we do not stop to ponder why life is the way it is

    It is the nature of the human mind to innovate
    and to develop solutions for problems
    This is what has created who we are today

    The first commentator brings up a very good point
    If we did not innovate, and in effect “play god” to change the way our world is
    we would not be enjoying the lifestyle we do today
    Every new drug that prevents or treats a disease
    is, in a sense “playing god”
    so doing so appears to have benefited us a great deal
    I don’t think there are many amongst us who would wish to return to the days of surgery without anesthetic

    So is aging to be treated in the same vein?
    If we did conquer aging, this would herald an entirely new view of life
    Our life may become even more valuable
    as losing it would mean losing timelessness
    And how would it impact having children?
    If nobody ever died, it becomes problematic to continue having children
    and then there is the moral question which will inevitably be related to inequity
    for we can already see that a technological extension of life
    will be usurped by the wealthy who could afford the treatment
    leaving the impoverished to continue dying

    From an Eastern perspective, however
    the fear of death is seen to arise from the construction and continual reification of ego
    The ego is that psychological construct that solidifies itself into existence
    after reaching a particular level of psychological and intellectual maturity

    Though the world is in constant flux
    including ourselves
    the ego creates a false sense of stability and motionlessness
    and it clings to that artifice
    and from that evolves fear

    This is on top of the survival instinct we already possess
    and which evolutionary scientists will of course argue is an evolutionary adoption for survival

    Meditation is a technique which may have evolved
    to deal with our finite lifespan
    to reduce the state of fear as we leave life

    I have no answers
    but am only trying to contextualize the many fundamental ideas
    at the core of both our personal lives and our collective humanity
    which the conquering of death brings up

    I guess what I am trying to say
    is that aging research needs to be approached holistically
    as it’s success will have profound impact on every single human being

  5. Where can I find a modified and standard dose of oxyconin and where can I find fenugreek,at 70 I have nothing to lose by trying a lo dose. AJ

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