Dr. Valter Longo on Resetting Autoimmunity and Rejuvenating Systems with Prolonged Fasting & the FMD
[Rhonda]: Hello everyone, I’m sitting here
with Dr. Valter Longo, for a round two podcast.
I’m pretty excited to be back, it’s been a
couple of years since our last discussion,
In my mind, you are one of the leading experts
in this realm of how diet and lifestyle all
regulate longevity, particularly when it comes
So, there’s been a really big interest in
fasting and also in limiting food intake,
and limiting food intake is actually one of
the probably most, I would say, reproducible
interventions that’s been shown to modulate
the aging process across multiple organisms.
So, I was wondering if you could maybe describe…define
and sort of describe some of the common denominators
between various modalities of limiting food
intake like caloric restriction, intermittent
fasting, prolonged fasting.
So, I think that we’re at the point where
we have to start…we have to stop using terms
like intermittent fasting, because it covers
almost everything, right?
I mean, at least in the journalist mind, when
they talk about intermittent fasting, it covers
from two hours food…not eating, to one month.
And of course they’re completely different
practices and they have completely different
And so I think it’s important to start qualifying
what it is that we’re talking about.
So, intermittent fasting, I guess it could
be a way to include let’s say alternate day
fasting, and include what’s called the five-two,
so having two days a week of a very restricted
diet, and maybe it could also include the
one day a week of fasting, of complete fasting.
I think it would be fair to include those
three in intermittent fasting, even though
they can have very different effects.
Now, of course time-restricted feeding is
time-restricted feeding, which refers to let’s
say how long of a time you eat per day.
So 8 a.m., 8 p.m., that would be 12 hours
of feeding and 12 hours of fasting.
And then calorie restriction is that…of
course you can say some people use calorie
restriction to define everything that is calorie
restricted, but the people in the field talk
about calorie restriction, when they hear
calorie restriction, they think of chronic
reduction of calories below the normal level.
So, below the level that will allow you to
maintain a normal weight, and so chronically,
so if you do this all the time.
And then periodic prolonged fasting instead
is what we mostly work on, and it’s very different,
and it’s not intermittent in the sense that
it’s not something that has to happen in any
type of cycles, frequent cycles.
It can be done once a year, it can be done
10 times a year, it can be done 20 times a
year, and it refers to let’s say at least
2 days of fasting or longer, or 2 days of
a fasting-mimicking diet or longer.
So, what do they have in common?
I mean, some things may be in common, but
they are very different interventions, and
they each do something different.
I mean, I think we know now from the calorie
restriction field that the diet…I mean,
the restriction of calories like that can
have incredible effects on diseases, diabetes
particularly, but also cancer, cardiovascular
So this is really unbelievable effects.
I mean, the monkeys, we know that it can wipe
out diabetes completely.
It can reduce cardiovascular disease and cancer
But the monkeys either live a little bit longer,
or don’t live longer at all.
And this is what we and others, a few at least
suspected for a long time.
I was a student of Roy Walford back in the
early ’90s, and it was…I mean, being around
calorie-restricted people, it was very clear
to me that this was going to have problems,
but it was also very clear that this was going
to have huge effects on health.
[Rhonda]: For the monkey studies that you’re
referring to, there were two published, correct?
One from the University of Madison and one
from the NIH?
[Rhonda]: And neither of them increased lifespan,
but they increased healthspan?
[Valter]: No, no, no.
The Wisconsin increased lifespan.
Richard Weindruch was also a student of Roy
So, yeah, that increased lifespan.
But if you look at the lifespan that is based
on the disease-dependent lifespan, so the
mortality caused by major age-related diseases,
that was…there was a huge effect.
If you look at the overall survival due to
where all causes of mortality were taken into
consideration, then the survival curves are
very close to each other.
[Rhonda]: Would that be considered maximum
This one [inaudible 00:05:39]
[Valter]: No, this will be mean lifespan,
mean and maximum, right?
[Valter]: So, small effect.
They don’t have maximum because I think they
will have taken…at some point they had to
stop it so they couldn’t really get to full
It already took 25 years to do that.
So, I think it would have been difficult to
get maximum lifespan.
But the mean lifespan was extended in Wisconsin,
it was not extended at the NIA.
Of course the Wisconsin study had a controlled
diet that was much worse than the NIA-controlled
So the NIA had somewhat of an ideal diet,
at least ideal monkey diet, and the Wisconsin
The Wisconsin was a reasonably good model
for the western diet.
[Rhonda]: That’s interesting.
Okay, so there’s no really…I think there
was also maybe some different genetic backgrounds
as well from the monkeys but who knows?
[Valter]: Yes, probably genetic…
[Rhonda]: Do you know if in these studies
did they see common pathways…and I want
to talk about this with you.
Genetic pathways that are known to be modulated
by caloric restriction, were those changed?
For example, did IGF…were IGF-1 lowered
[Valter]: Yeah, now I haven’t looked at those
papers in a while, but almost for sure, I
mean, those were affected.
I mean, calories are cut by 30%, so that would
mean 30% less proteins and 30% less sugars.
So, yes, I will assume that both of them showed
effects on the nutrient-signaling pathways
and including TOR and IGF-1.
[Rhonda]: And I guess so that’s probably something
that’s also a common denominator between these
other modalities of limiting food such as
the periodic prolonged fasting.
I guess one of the major differences would
be the shift in metabolism to, when you’re
fasting, to beta-oxidation, to…because that’s…is
that something that occurs during caloric
[Valter]: That probably occurs.
There’s probably a minimal switch to a ketogenic
mode, depending on who it is and what the
So, it is possible that chronically, when
you’re chronically restricted, it also depends
how you restrict it.
So for example there are human studies where
they show that because the people that are
restricted were eating high protein, a high
vegetable protein diet, and the IGF-1 was
So, it is possible that some of these individuals
have a diet that would block entry into even
a small ketogenic mode.
But overall they’re probably not, they’re
relatively in a standard metabolic mode as
far as ketone bodies and fatty acids are concerned.
[Rhonda]: That’s interesting because you said
the diet was a high vegetable protein diet,
and I was thinking the study from I think
it was Dr. Fontana’s lab that showed that
humans that undergo caloric restriction naturally
gravitate towards eating more protein because
it’s more satiating, and so people that were
eating a higher animal protein diet, even
though they were caloric restricted, so they
were eating about 30% less normal food than
they normally would, their IGF-1 levels were
higher because the…
[Valter]: Were normal, yeah…
[Rhonda]: Yeah, they were.
And they didn’t go lower like they do in animal
[Valter]: Right, until they restricted the
[Rhonda]: Until they restricted the proteins.
[Valter]: So they actually did a second study,
Fontana and colleagues did the second study,
the follow-up in which they restricted the
proteins, and then the IGF-1 went down.
[Rhonda]: I haven’t seen that one, okay.
Yeah, I should definitely take a look at that.
But for people that are listening and kind
of wondering, we’re talking about one of the
major dietary regulators of the IGF-1 pathway
which maybe you can mention a little bit about
the role of IGF-1 in the aging process.
So, proteins, and particularly certain amino
acids, methionine, cysteine, etc., they regulate
IGF-1 levels, and IGF-1 in simple organisms,
at least the orthologs of IGF-1, as well as
in mammals seem to have an important role
It is not clear how much is IGF-1 versus insulin
versus growth hormone receptor-dependent signaling,
which is independent of IGF-1 and insulin,
but most likely it is the growth hormone receptor.
Growth hormone and growth hormone receptor,
they are the sort of master controllers, and
IGF-1 seems to be one of the axis that regulates
or accelerates aging in multiple cell types.
[Rhonda]: And from humans there are some,
there’s some evidence with polymorphisms and
various like growth hormone…?
[Valter]: Yeah, that’s actually our work with
not polymorphism but mutations in the growth
hormone receptor, something called E180 mutation.
And the people…Well, we knew from mice,
from the work of John Kopchick and Andrzej
Bartke, that mice that have either a growth
hormone receptor, or growth hormone deficiency,
live longer, about 40% longer, they also live
That’s probably, you know, I think one of
the most important observations made in the
aging field, that you could live 40% longer,
and yet about half of the mice get to the
end of life without any obvious pathological
lesions, so they don’t develop diseases.
And that the control of disease is less than
So, and these…
[Rhonda]: It’s pretty significant.
[Valter]: I’m pointing these out…Well, it’s
a huge effect right there.
I’m pointing these out because obviously people
think that if we extend the lifespan of, human
lifespan, then it’s going to come with a lot
of more problems.
And instead, in the mice, but also in our
work in humans, where we’ve been following
these people with growth hormone receptor
deficiency down in Ecuador, and they’re called,
there’s a syndrome there, a syndrome called
So they’re very much the equivalent to the
mice, and they don’t have a very long lifespan,
they may live a few years more than their
relatives, they don’t have homozygous growth
hormone receptor deficiency, but they’re protected
from cancer, they’re protected from diabetes,
and a recent paper showed that they seem to
be protected from age-dependent cognitive
decline, and all of these are matched by the
So that makes you feel a lot more confident,
having the mouse data suggesting that this
is concern the fact of having low growth hormone,
of course and then low IGF-1, low insulin,
and low TOR, and also I think low Ras, at
least expression activities a little bit harder
to figure out in people.
[Rhonda]: Have you measured the IGF-1 levels
in these people with Laron’s syndrome?
You’ve measured their IGF-1 levels, is that
something that’s achievable from doing the
caloric-protein restriction or the fasting,
which we should probably start talking about?
[Valter]: Yeah, we measure the IGF-1, it’s
very low in these subjects.
[Rhonda]: Very low.
[Valter]: Yeah, it’s like 10% of the normal
IGF-1, circulating IGF-1 levels.
So there’s extremely low IGF-1, low insulin,
and also we have…What we’ve done is we’ve
taken the…this of course we can measure
in their serum, right?
But then we’ve taken the serum and we took
human epithelial cells, and we expose the
human epithelial cells either to control serum,
or to the serum in the Laron’s, and then we
looked at the gene expression.
And that showed that not only the TOR was
down-regulated, so was Ras, at least gene
expression-wise, and a number of other genes
that are associated with accelerated aging.
[Rhonda]: And cancer.
So maybe we can…I kind of took us off into
the tangent here, but the fasting, you’ve
done a lot of work on both, doing periodic
fasting, water fasting, and also a fasting-mimicking
diet which you can explain in a minute.
So I was kind of…I found it kind of interesting,
like the reason why you developed the fasting-mimicking
diet, at least I read in your recent book,
“The Longevity Diet,” was if I’m correct,
because you were doing some studies on cancer
And, is that correct, the…
So we…Well, first of all for a long time
I had been thinking about how to get the benefits
of calorie restriction without the problems
of calorie restriction, and so that was something
that I was looking for.
And also I, you know, back in the days in
my graduate work, you know, we were starving
yeast and bacteria, and we had shown that
this was very beneficial.
So I was really…I wanted to look at the
possibility that prolonged fasting will be
And so…then also the point when we discovered
that the proto-oncogenes, so the normal versions
of the oncogenes that are so central in cancer,
they are the genes that control cellular protection.
And so from that came the idea that…and
maybe we discussed that already in the first
But that came the idea that if you starve
a system, the normal cells would become protected,
and the cancer cells will remain sensitive,
so then we started testing this in cancer
patients, but realized that they didn’t want
And then I think they gave us an opportunity
and the motivation to look for a fasting-mimicking
diet, so a diet that works as well as fasting,
but allows patients to eat.
And this was funded by the National Cancer
Institute first, and then by the National
Institute on Aging.
And so it’s of course exploring all these
understanding, all the understanding of the
connection between let’s say amino acids and
TOR and IGF-1, sugars or certain sugars, and
PKA actually we’d shown that, as we had shown
for yeast, we now shown in mammalian cells
that glucose levels activate PKA, and so that’s
part of the…that’s a lot of what went into
the development of a diet that can nourish
the patient and yet have effects on IGF-1,
IGFBP-1, ketone bodies, and glucose that is
equivalent to that of water-only fasting.
[Rhonda]: So you basically looked at all these
known genetic pathways from your work and
others that…so IGF-1, mTOR, PKA, Ras?
[Valter]: Yeah, Ras.
Although Ras may or may not be conserved.
The role of Ras, we didn’t really see it in
mammalian cells yet.
I mean, it’s probably there, but we didn’t
see it at least in the cells that we looked
at so far, you know?
It looks like IGF-1 and glucose can directly
feed into PKA, and IGF-1 can feed into PKA.
So we think that PKA is very central, maybe
handling both the protein signaling and the
Yeah, that’s…the interesting…what are
your thoughts on…and I’m going on a tangent
here, I’m going to come back to it, but the…because
you just mentioned this.
The role of insulin in regulating IGF-1, I
guess both function and also level.
So there were some studies that I…and I’m
not sure if this was Fontana or who did these
studies, but there are studies showing that
limiting the glucose intake was important
for bioavailability of IGF-1 through some
of the insulin…IGF-1-binding proteins like
IGF-1 binding protein 1, and also for regulating
transcription of IGF-1.
So, it’s kind of…
[Valter]: So it’s all interconnected.
Obviously we don’t know enough, you know,
the association between…I mean, insulin
and IGF-1 are very similar, they can interchangeably
bind to the receptor, each other’s receptor
with different affinity of course, and so
yeah, we…how are they connected?
I don’t know and I’m not sure that that is
very well understood, but those are certainly
connected and they’re certainly linked, both
linked to growth hormone signaling.
[Rhonda]: I think there was another study,
and this was in animals, and this is what
really piqued my interest.
I’ll look up the reference and send it to
you if you haven’t seen it already, where
I think the protein, limiting the protein
intake, essential amino acids specifically,
wasn’t as key if the total kilocals were kept
under a certain level, in terms of activating
So that there was like this sort of energy
threshold where if you had low enough energy
specifically from like glucose, then your
protein, your essential amino acids can go
a little bit higher than they’d otherwise
And this will be consistent with our work
Yeast when you have, when you look at the
aging rate, it’s very clear that there is
a network, and it’s not really a pathway.
And the network is very much interconnected,
you know, PKA and TOR, and everything else
and AMP kinase.
And so actually in yeast, the sugar seems
to dominate, and the proteins seem to be second
So if you remove sugar and you increase the
protein consistent to what we were just saying,
that’s not so, then it’s not so bad.
But if you have both the sugars and the protein,
then you see much more the protein-dependent
[Rhonda]: Yeah, it’s extremely interesting.
So, I’ll look up the reference too in case
you haven’t seen it…
[Valter]: And of course in the case of yeast
is individual amino acids, there’s no protein.
[Rhonda]: So, we went out back on a tangent,
but this is why these discussions are so interesting.
But so you were talking about the development
of the fasting-mimicking diet, and how you
were looking at all these genetic pathways,
and also you mentioned the ketone bodies and…what
was the last thing for…
[Valter]: Ketone bodies and glucose.
[Rhonda]: And glucose, right.
[Valter]: IGF-1, IGFBP-1, glucose, and ketone
[Rhonda]: And these are all things that regulate
cancer growth as well?
[Valter]: Yes, they can regulate cancer, they
do regulate many cancers in different ways.
I mean, ketone bodies, you know, some will
argue that they hurt cancer cells, but some
cancers actually love to use both ketone bodies
[Rhonda]: Yeah, there was a recent publication
[Valter]: So you can actually accelerate cancer
growth with ketone bodies, but you can also
hurt cancer cells with ketone bodies.
This is why ketogenic diet, you know, I wouldn’t
get too confident about using ketogenic diet
alone against cancer cells because of course
even fasting, a lot of cancer cells can adapt
to the changed environment.
[Rhonda]: Yeah, cancer is a very…it’s so…it’s
so complicated when it comes to cancer and
it seems like really…you really have to
be careful when you’re trying to treat the
And I think that there is a lot of, of course
interest on the ketogenic diets and cancer
treatment, and it’s good, I think it can do…there
are situations where the ketogenic diet can
hurt the cancer growth.
But as for fasting, we see that you need to
have in most cases the powerful target intervention
with the fasting.
So like fasting and chemo, fasting and kinase
inhibitors, fasting and immunotherapy for
So, I will assume that the ketogenic diet
alone is going to be a complementary intervention.
So now for example we’re very interested in
what happens if you do fasting, ketogenic
diet, and cancer treatment together, you know?
That I think is very promising.
Particularly if you do it in the sense of…And
we have patients that, with very aggressive
phenotypes that are doing this.
So they do the periodic fasting-mimicking
diet, then in between the ketogenic diet,
and then they keep doing the radiotherapy,
and particularly like gliomas, radiotherapies
And this seems to be working, or certainly
very promising what we’re seeing.
[Rhonda]: Is this an ongoing trial you’re
talking about, or is it just…
[Valter]: We haven’t started…I mean, we
have trials on cancer, a number of trials
We don’t have one on glioma yet, but I know
that some groups in Arizona, they are…But
then mostly they have just done it with a
But because it’s so aggressive, and most people…you
cannot tell like glioma patient, wait until
the clinical trial is ready, right?
Because it’s a very quick-moving cancer.
So, in some cases we just say, look, go to
your oncologist and ask them if they’re okay
letting you follow a fasting plus ketogenic
diet plus standard of care.
So they’re just adding ketogenic diet and
fasting to the standard of care.
[Rhonda]: Yeah, okay.
And that’s, so the, for the periodic fasting,
is that also including the fasting-mimicking
diet which they can talk to…
The fasting-mimicking diet, I mean, not water-only
fasting, but FMD, ketogenic diet, and standard
[Rhonda]: So I do remember that at least with…there’s
been a couple of studies that you were involved
on with water fasting, you showed a combination
with standard of care treatment, it seemed
to be safe, and also to some degree you seemed
to sensitize some of the cancer cells to death,
and also maybe even protect some of the normal
cells and some of these blood cells.
They weren’t getting neutropenia or the myelotoxicity
quite as significant as people that didn’t
do the fast.
Do you have any…Now, I know you’ve published
studies on the fasting-mimicking diet in animals
and cancer, in combination with standard of
Is there any clinical trials that you’re planning
on doing with fasting-mimicking diet on humans?
No, we’re doing it, right.
So, we’re going a little bit slower than predicted,
in part because we didn’t see coming the food
So patients, when you give them any food with
something that is toxic, they develop a food
So, anything that you give them with a toxicity,
is now recognized as toxic also.
And so now we’re having to develop a number
of new foods specifically to avoid the repetition.
You cannot repeat anything twice essentially
for…So if somebody has eight cycles of chemotherapy,
you know, we may have to give him eight different
things, all respecting the formulation requirements.
So, yeah, that surprised us little bit.
But we already, couple hundred patients have
already been involved in these multiple randomized
And then the good news is that there is no
problems, we don’t see any problems with the
fasting-mimicking diet in cancer treatment,
but it’s been slower than expected because
of these, you know, A, because of course you
cannot promise, you cannot go to a patient
and say, oh, this is going to make you feel
And if you give them a pill, it’s much easier
because there is no effort on the part of
With the fasting-mimicking diet, if you knew
it was going to be much better for you and
somebody told you, I don’t think it would
be a problem because we see it with a healthy
But if you don’t know you have cancer, and
then you have this food aversion, altogether,
it makes it very tough for people.
So we had about a 40% thus far compliance,
and so now we need to tweak it so we get to
[Rhonda]: Yeah, it sounds like a challenge.
But if there are oncologists right now that
are interested in using the fasting-mimicking
diet in combination with their standard of
care treatment, that is something that they
[Valter]: Well, yeah.
The way we’ve been putting it is that they
can, if the patient cannot wait for the end
of the clinical trials, and the oncologist
agrees, you know, for whatever reason that
they cannot wait, then they can certainly
do it with the standard of care.
So they do a standard of care, and then the
fasting-mimicking diet along with that.
Now, the FDA prohibits any product or any
claim related to disease prevention or treatment
for something that has not been FDA-approved.
So then, you know, I think an oncologist should
be very careful in presenting it to the patient.
So it has to be presented as something experimental,
that could be good for them or could be bad
So that said, of course in mice we have incredible
results, we and many labs now have repeated
this, so works very, very well.
And so, you know, if somebody cannot wait,
I think then it’s fair to go to an oncologist
and say, “Obviously, I’m running out of options.
Shall we consider this one?”
[Rhonda]: What does it take to for…how many
like clinical trials does it take for FDA
to approve something?
[Valter]: No, the FDA is a specific process.
So you have to enter, you have to file, it’s
an IND application, and there is…it’s a
very expensive and long process, and it’s
not just trial.
So, it’s three phases, phase one, two, three,
and in the end you probably have between 500
and 1,000 people, 1,000 patients, and then
they make a decision based on the data, whether
it’s approved or not.
The whole process usually costs about $50
And so, you know, this is what makes it complicated,
Because, yeah, it’s not easy to justify this
kind of investment on a diet, you know?
[Rhonda]: So you do have evidence, and this
is a recent publication of yours, that the
fasting-mimicking diet in healthy subjects
can, it seems, affect biomarkers that are
related to aging in a positive way.
[Valter]: Yes, aging and as well biomarkers
for aging, as well as risk factors for diseases,
So this was a clinical trial, a randomized
clinical trial with three cycles of the fasting-mimicking
diet once a month for five days, for three
months in a row, and then of course we looked
at baseline and it was a randomized crossover.
So, in each case you’ll have a group of controls,
a group on a control diet and a group on the
fasting-mimicking diet, and then the crossover.
And yeah, the results are remarkable.
I mean, first of all, if you are a healthy
person with say a healthy or a low blood pressure,
nothing happens to you.
And this is a really nice distinction with
calorie restriction for example, right?
Earlier we were talking about, you know, are
they all going to the same place?
I don’t think so.
So calorie restriction, chronic, it keeps
driving your markers down.
So, even if you started…I mean, if you look
at Biosphere 2, and these were then confirmed
by Fontana and others, if you look at Biosphere
2, even people that had at the beginning a
low blood pressure, they kept dropping, and
by the end of it, they had pressure like 85/55.
And same thing for cholesterol, same thing
for triglycerides, almost everything, usually
drop to very low levels.
The fasting-mimicking diet itself, it seems
to…you know, if you have a blood glucose
of 75, nothing changes, it doesn’t drop it
If you had a fasting glucose of 106, almost
in every case, it brings you back to normal.
This is very interesting, and also very good
So now we have close to 3,000 doctors just
in the U.S. that are recommending the prolonged
fasting-mimicking diet, what was tested in
the clinical trial, and this is a very important
So, the three cycles decreased, in normal
people did nothing, in people that had…I
mean, I shouldn’t say did nothing.
Did nothing that you can see in terms of markers,
because they already had good levels of these
But in people that had elevated cholesterol,
it decreased cholesterol.
The people that had the elevated triglycerides,
it decreased triglycerides.
People that had the elevated IGF-1, probably
people eating on a high protein diet, it dropped
And the highest people dropped dramatically,
you know, it came down about 60 points.
And the people that had the high fasting glucose,
People with blood pressure that was elevated,
both the systolic and diastolic, had major
The people that had CRP, systemic inflammation,
in almost every case they moved back to the
So it’s really powerful I think in resetting
the system somehow, that it’s getting out
of the…its functional ideal state, it resets
it, and I think it really rejuvenates.
Now we’re doing…we’re trying to calculate
based on published profiles, and also methylation
profiles, is this rejuvenating you?
And also A and B, after three cycles, what
is your risk for diseases in the next 10 years
at baseline, and what is your risk after three
And we suspect there’s going to be a drastic
change, just…You know, if you think about
it, it’s three months, right?
[Rhonda]: And this was a five-day fast each?
It was one week…
[Valter]: Yeah, five days of…three cycles
of a five-day fasting-mimicking diet, and
then we measured again, and of course all
these things that I just say change.
But what if we go to the databases and we
plug in the numbers, and we say, tell me,
you tell me, what is the risk now compared
So we haven’t finished that yet, but I think
And I’ll just say there’s very…the results
look very promising.
[Rhonda]: I have a couple of questions.
So first the…you measure these biomarkers
at baseline and then after the three cycles.
Do you think if you were to have measured…you
measured them immediately after the third
[Valter]: One week.
[Rhonda]: One week?
So, do you think…
[Valter]: And three months.
And we also measured again three months
[Rhonda]: Oh you did?
And how were they…that was my question.
So, what were they like three months later?
Do you have to keep doing it every, you know,
I mean, there were, about 60% of the effects
were still there.
So you could tell that they were smaller,
but 60% of the changes were still significant.
So this is why we say that on average people
probably need to do it once every four months,
and it’s also important to point out that,
you know, until millions of people do it,
it should be on a need-to-do-it basis, right?
So, if you are an athlete, you have a great
diet, you know, low protein, pescetarian,
and you do all the right things, you exercise,
etc., you probably only need to do it once
or twice a year.
It’s not very many people in that category,
maybe like 5% of the population.
And then as you move to a problem state of
course, then, you know, the minimal risk that
is associated with doing a fasting-mimicking
diet is a good risk to take, because of course
any drug that you take, any intervention that
you do is going to have risks.
And so now I think people, there’s over 25,000
people that have done the fasting-mimicking
diet, the prolon, the same diet that was tested
We’ve had very few severe side effect reports,
And even the ones that had severe side effects,
they fully recovered and there was no evidence
that it was the diet that caused them, right?
So, it’s very good news, right?
Then when you get to, this is what in the
FDA terms would be considered a phase four,
when you say, well, let’s keep monitoring
this once it’s out in the market and see,
you know, are there people that eventually
show side effects that we didn’t see in the
FDA trials, right?
Of course we didn’t do FDA trials, but…So
we have done phase one and phase two, and
skipped phase three, and now we’re in phase
[Rhonda]: Wow, that’s really great.
Twenty-five thousand people, that’s a lot.
So you were mentioning the frequency changes,
the frequency of doing this fasting-mimicking
diet may change according to someone’s health
status and how, what their lifestyle is.
So someone that’s obese or has high cholesterol,
high triglycerides, high fasting blood glucose,
all these markers that you mentioned, may
want to do it more frequently like…
[Valter]: Well much more frequently, yeah.
So, somebody that has those problems, say
obese, multiple markers for disease, or risk
factor for disease, then once a month, yeah.
And that’s what the doctors have been doing.
So they put them on once a month, and then
monitor the changes.
If it works, then you can keep it going.
It doesn’t mean they’re going to do it once
a month for their entire life.
The hope is that you slowly…And that’s also
very important, this idea, especially with
obese people, we’ll see how it works, but
this idea that you can go back to your diet
after five days, right?
This is very mentally, to people is very important.
Say, “Well, struggle for 5 days, but then
leave me alone for the next 25.”
That I think is both potentially at the mechanistic
level, but also the psychological level it
could be a good way to go.
[Rhonda]: So I’ll just tell you, I have a
friend of mine who was morbidly overweight,
I mean, he was morbidly obese, he was, I think
at his highest weight was about 400 pounds,
and had tried all sorts of types of diets,
you know, and never could really get anything
to work and the compliance was low.
But then he started doing these prolonged
Now he was doing, you know, five, seven days,
and he was doing it frequently, like once
a month, and he’s lost 200 pounds.
And I think for him, and he does exactly what
He likes food.
He likes food, and he likes to eat certain
foods, but he’s found something that works
for him, where he can, he just, you know,
once a month he does a five-day fast, and
then he goes back and he eats his…
[Valter]: I want to talk to this guy.
[Rhonda]: Yeah, I would absolutely like to
put you in touch with him.
He’s actually applying to medical school now,
but he’s a very smart guy.
He’s a lawyer, and now he’s going back to
medical school because he’s become very interested
in obesity and all this stuff.
[Valter]: So we’re running our trial in Holland
on diabetes patients, many of which are going
to be obese, and yeah.
So, that’s our hope, that hey, you know, people
always ask, you know, there’s famous papers
that have shown what they call the yo-yo diets,
They’ve shown that these can actually lower
If you have this prolonged starvation period,
it can lower your metabolism and then you
tend to gain weight.
But in mice and in humans we’re seeing really
the opposite, you know?
Doing it this way.
So if you take somebody and you put him like
say two months on a very low calorie diet,
and you make him exercise, that seems to be
Because of course they can’t keep doing that.
And then when you eventually go back to a
normal diet, your metabolism is now slow.
But doing it like this for these five days,
particularly in the fasting-mimicking diet,
seem to be not doing that.
So the body doesn’t quite ever switch to a
slower metabolism because it’s so short.
So I think, we’ll see, but I think it may
very well represent a very good way to psychologically
and also physiologically get the people to
help them have a long-term plan to lose weight.
[Rhonda]: For me I would almost think that
you’d have the opposite effect that these
yo-yo diets that people are claiming lower
your metabolism, I would think because you’re
spending five days in more of a fasting state,
or a fasting-mimicking state, that you are
becoming more metabolically flexible because
you’re switching to being able to oxidize
fatty acids and then…so you’re being able
to kind of switch between carbohydrate, you
know, using glucose as the main source of
energy and using fatty acids…
[Valter]: Not only switch, but what we suspect
is happening…in mice we’ve shown that per
month, if you take mice and you put it on
a fasting-mimicking diet, they of course have
less calories during the five days, the four
days in the case of mice, but then their metabolism
seems to be speed up to the point that per
month they eat the same calories.
So they over-eat everything they under-ate
during the four days, right?
[Valter]: So they eat exactly the same, but
they lose a lot of weight.
So we suspect that what’s happening is that
fat-burning mode keeps them going.
So they never quite…I mean, they probably
get back to a relatively normal metabolism,
but not quite the same.
So they keep burning fat a little bit, to
the point…I mean, we’re investigating this
now at the molecular level, but that’s where
we suspect that…
And of course people we saw the abdominal
fat loss and we saw the weight loss, and so
we suspect that the same is happening.
Another interesting thing which makes a lot
of sense, we didn’t think about it too much
at the beginning, but the muscle is…So almost
every diet, including calorie restriction,
you lose fat, water, and muscle.
And almost every diet is the same way.
And in this case it’s really interesting because
you now temporarily lose muscle, and of course
you lose abdominal fat because after a few
days this becomes your reservoir.
I mean, all the…it doesn’t touch subcutaneous
fat for some reason, and only goes to the
main depot, the visceral fat.
So that’s great news.
But the muscle is also decreased.
But then, when you refeed, the muscle is rebuilt.
I mean, we have evidence for regeneration
in mice, we don’t know yet in humans.
But certainly the people go back to their
normal muscle mass.
So now you have a specific effect on visceral
fat, no effect on subcutaneous fat, and no
or very little effect on even absolute lean
In fact the relative lean body mass goes up.
[Rhonda]: Yeah, because in your study the
lean body mass…
[Valter]: Relative goes up.
Absolute, either in one arm wasn’t affected,
in one arm was just slightly decreased.
So, good news because it’s probably one of
the very few methods to maintain normal lean
body mass while losing fat.
[Rhonda]: And that’s very important to a lot
I mean, you don’t want to lose muscle mass.
Muscle mass is also very important for longevity.
And that’s actually a question I was going
to ask you because I wasn’t sure what the
mechanism was, but the shrinking of the organs
and then sort of in the refeeding phase the
re-growing, is kind of something I wanted
to talk to you about as well, this rejuvenation
process, because you’ve obviously shown this
now in several different studies both with
fasting and fasting-mimicking diet in animals,
where they lose a significant amount of their
different organs, right?
And I think that you…maybe you want to talk
about this, the…what…
So in mice for example, if you look at the
weight of most organs, and this of course
was known for calorie restriction long term.
But with fasting, and fasting-mimicking diet,
this happens much more rapidly.
So the organs will be smaller, and at the
end of the days of fasting-mimicking diet,
and then you refeed and of course they go
back to the normal level, right?
So there is really, there is this shrinking
and re-expanding effect.
Now, we don’t know how much of it is cells
becoming smaller, versus cells being killed,
but clearly there is killing of cells.
And certainly of course we are also very interested
in, is there preferential killing of the damaged
And we’ve started to show that in our multiple
sclerosis mouse model, and also the human
study, there was evidence that the white blood
cell level temporarily was reduced during
the, at the end of the fasting cycles and
then went back to normal.
So yeah, so we suspect that there are these
fasting-dependent, depletion of both intracellular
components, you know, autophagy, and cellular
components, and then we’ve shown the stem
cell to be activated, and then the stem cell
during the refeeding part.
And that’s another very important point, is
that differentiates it to most of other interventions,
All of a sudden…even the intermittent fasting.
Because you don’t have enough time.
If you do like even one day, it barely even
gets you into the ketogenic mode, right?
And of course if you do it for one day, you
wouldn’t want to break down too many of the
That’s probably…having all the glycogen
and having all the digestion takes 30 hours
to complete the food digestion, from the time
you eat to the time that all the calories
have been taken up, it takes probably over
So that’s a very important distinction between
the prolonged fasting and everything else,
including calorie restriction, which does
not have the refeeding moment, right?
So, if the rebuilding happens during refeeding
and you never have it, then of course you’re
missing out the reconstruction part, which
is as important as the destruction part.
[Rhonda]: You brought up so many different
interesting points that I kind of want to
So first the threshold between, you know,
like you’re mentioning the threshold between
when you’re actually getting rid of intracellular
compartments through autophagy, clearing away
protein aggregates, pieces of DNA and things
like that, but also, and damaged mitochondria,
but also the clearing away of complete cells,
and particularly damaged cells, which is very
interesting to me, because as you mentioned,
you’ve shown this now and there’s two different
animal models for autoimmune disease, one
was multiple sclerosis and the other was the,
I think type 1 diabetes.
[Valter]: Yeah, ours was not, that one particularly
wasn’t, was not autoimmune.
We’re doing the autoimmune.
There’s type 1 induced by, pharmacological
So it has potential for…
[Valter]: Yeah, but I can tell you, we’ve
now confirmed it with all the autoimmune diseases.
So I think it’s going to be applicable to
many autoimmune diseases.
[Rhonda]: So this is what’s so cool because,
I mean, the, you know, the potential for this
type of fasting to cause cells that are preferentially
damaged to be cleared away by apoptosis, which
I mean, I spent six years studying apoptosis
and cells that are damaged preferentially
die, I can tell you from doing multiple, multiple
[Valter]: Even during development, right?
I mean, that’s the way that the good and the
It’s also how cancer cells are primed to die
as well, because cancer cells are damaged.
They are mutated and completely damaged, and
that may be also why they’re very sensitive
[Valter]: Yeah, and also, I mean, something
that is a speculation but we’re starting to
think more and more, or at least I’m starting
to think more and more, is that…You know,
I always say if you cut yourself, it doesn’t
matter where you cut yourself or if you hurt
your head, the system repairs it, right?
Or repairs almost anything.
And so what about the inside?
You know, is it possible that we never developed
a way to fix damaged organs and various systems?
So we’re starting to think that maybe fasting
represents that opportunity to fix the inside,
And maybe, and just maybe, because everybody
had to do it by force, they were forced to
do it because there was no food at some point
of your month, almost unavoidably you probably
were with no food.
And so because it was almost unavoidable,
it was probably something that…you know,
I always also think about sleep, right?
And in sleep you feel so tired that you have
Because obviously people wouldn’t have gone
to sleep just on their own right?
But in the case of fasting, because it was
imposed by the environment, I suspect that
maybe we never developed something that forces
you to fast.
And so now that we eat all the time, which
completely lost this auto-repair mode, right?
And this could be remarkable because imagine
if we had this ability if you have damaged
liver, that fixes it.
If you have damaged immune cells that are
autoimmune, that clears it.
And so you never develop defense against autoimmunity
because fasting always took care of it.
Now all of a sudden you get rid of fasting,
and all these things start building up, whether
it’s insulin resistance, or liver damage,
fatty liver, etc., etc., right?
So, this could be really…and people always
are surprised when we say, you know, we’re
publishing on all these different diseases,
but if that’s true, then that make sense,
[Valter]: Because for example, in multiple
sclerosis, you see on one side it kills the
It then turns on the stem cells, then turns
on the oligodendrocytes, progenitor, and replace…I
mean, it’s very…it’s like, how the hell
does it know how to do all of this?
And it does it all in such a sophisticated
But if it was an evolved process, that would
make a lot of sense.
[Rhonda]: The thing that’s so interesting
is how the stem cells, you know, the clearing
away of these damaged cells through apoptosis,
activating these stem cells which then have
to repopulate whatever organ or tissue we’re
talking about, how they actually can make
normal life cell.
You’re talking about in the case at least
for autoimmunity or type 1 diabetes or multiple
sclerosis, how they make their immune cells
normal, that is so…
[Valter]: Yeah, but that makes sense, right?
Because if you turn on a stem cell, you imagine
now that the…you’re not going to turn on
a damaged stem cell, there’s got to be a selection
process to pick the…So the stem cell is
now of course going to give rise to normal
white blood cells, right?
They wouldn’t have any way to make an autoimmune
So, I mean…yeah.
So because that happens I think in the differentiated
cell, the clonal, so you expand already the
So even I think theoretically that makes perfect
sense that once you turn on the stem cell,
the hematopoietic stem cell, you will make
a healthy…Now, you can always turn the healthy
cells into autoimmune cell, but at least initially
you will make a healthy one, and that’s exactly
what we see happening.
[Rhonda]: So the refeeding phase is really
important for, I recall in our last discussion
you mentioned the refeeding phase was really
important for the stem cell proliferation,
so after you activate them, you want them
to proliferate and continue to grow.
And you had mentioned, if I remember correctly,
that IGF-1 played a major role in that proliferation
because it is after all a growth signal, you
[Valter]: Yes, so there’s no doubt.
We haven’t spent too much time on it but it’s
pretty obvious that, you know, you’ll need
growth factors to do that.
So, this also makes us think about for example
the clinical trial, the multiple clinical
trials that were done on IGF-1, in cancer,
that failed, right?
And we thought, well maybe they failed because
the IGF-1 was also needed for example for
the immune system to be built or rebuilt,
and, in those trials, right?
So then the generation of healthy cells is
as important as the low IGF-1…generation
of healthy cells is IGF-1-dependent, is probably
as important as the killing of damaged cells
that is low IGF-1-dependent, and the turning
on of stem cells, which is also low IGF-1-dependent.
[Rhonda]: Oh, it’s low?
I thought it was higher, the…turning on
the stem cell…not turning on, the proliferation
of them is high IGF-1, correct?
[Valter]: Yeah, no, but the turning on, the
initial one is low.
So low now is the signal to self-renew, you
[Valter]: So now you have a population, a
small population of stem cells that are just
active and standing by.
Then probably when IGF-1 goes back up, now
they are the ones that are pushed by IGF-1
to proliferate and to differentiate, probably
also to differentiate.
Proliferate and differentiate.
Because now you want to rapidly make…
[Rhonda]: Make new cells.
[Valter]: …a lot of white blood cell for
example or whatever it is.
[Rhonda]: So that’s my question about, my
question to you then is for the refeeding
phase then, you may…is that…do you think
then for example having some protein would
be a little more important because you want…protein
being essential amino acids…because you
want a little more IGF-1 activated during
that specific time window?
Is that something that you…
[Valter]: Yeah, there is no doubt that when
you refeed, you have to have sufficient protein
And if you don’t, I mean, you really don’t
have the bricks to rebuild whatever system
you partially broke down.
So yeah, protein…and also protein are going
to drive the IGF-1.
So the whole system of course is set up to…the
sugar and the protein is set up to give the
signals to rebuild, which is probably through
Insulin and IGF-1.
So just, since we’re running close to out
of time here, what are your top five biomarkers
that you think are indicative of something
that people can…that are indicative of healthy
aging that people can maybe go to their clinic
[Valter]: So if you…I went to the clinic…I
mean, if you’re talking to the masses, and
you’re talking about health or you’re talking
about pure longevity?
[Rhonda]: Well, I mean, I’m talking about,
you know, maybe both.
If there’s…I don’t know if there are other
longevity markers that people can do now that
are clinically available?
[Valter]: I mean, yeah, I think there are
things that you can measure, that may predict
[Rhonda]: Okay, let’s do longevity, let’s
do, yeah, biological age, let’s say.
[Valter]: Yeah, biological age I will certainly…you
know, this is what are markers, certainly
IGF-1, insulin, glucose, inflammation, systemic
inflammation, so CRP, most doctors can measure
You could also, if you wanted to add, I mean,
And then you could add things such as for
example fatty liver.
These are more pathological or pathology-oriented,
but certainly they can be major determinants
of, or certainly can influence cellular functions
like insulin resistance.
And so those are some of the things that I
would, I want to see in the ideal range.
Of course blood pressure is another one.
Then Morgan Levine, she’s now at Yale, she
has, she and others have a set of markers
that are taken from large population and they
seem to be predictive of biological age, and
I don’t…some of the ones that are overlapping
were the ones that I said, but there are other
ones that are not, that I didn’t list.
So, people can look up her papers.
And also of course, you know, the methylation
profile, that seems to be predictive of…I
mean, nobody does it now I think to the public…
[Rhonda]: That’s Steve Horvath’s work you’re
[Valter]: Yes, but I’m assuming that soon
enough it is going to be available.
[Rhonda]: Is it?
Please let me know when it is, because I’m
[Valter]: I saw there are commercials now
about telomere measurement at home, right?
[Valter]: So now I’m assuming that soon enough
people are…at least a doctor will have the
ability to assess methylation patterns.
So you have a new book out, called “The Longevity
Diet,” which is the longevity diet…
[Valter]: Yeah, “The Longevity Diet,” and
it’s divided into two sections, the first
half is all about everyday diet, and in this
everyday diet I talk about five pillars of
I basically say let’s base the decision on
diet on epidemiological studies, centenarian
studies, basic research focus on longevity,
clinical studies, and studies of complex systems.
And complex system being cars and planes.
And I always thought that it’s very, a very
good way to remove, I mean, together with
the other four pillars, to remove all the
uncertainties and say, well how do systems
that we build age?
To just get a fundamental understanding of
the environment and how the environment affects
the complex systems.
So the first health is that.
And centenarian groups, the ones that have
record longevity from around the world who
were really important.
You know, for example I always say to people
the ketogenic diet, well let’s look at groups
that have record longevity that use the ketogenic
None of them.
So, that’s very important to say for the safety
component once you make a decision about what
the science tells you, it’s always good to
look around the world and say, how commonly
used is this diet?
And if the answer is, it’s not used at all,
you’re really taking a chance on this diet.
And the other half of the book is about the
fasting-mimicking diet, and you know, on normal
people, some of the things we discussed, and
then a chapter on diabetes type 1 and type
2, there is a chapter on autoimmunities, there’s
a chapter on Alzheimer’s and neurodegeneration,
and a chapter on cancer.
So it goes through all the major…and a chapter
on cardiovascular disease…all the major
diseases, and tries to, you know, mostly based
on data out there, and combine it with what
we learn, to try to provide people with complementary
So for example if you look at diabetes, basically
it says, well, here’s what you could do every
day, but then you can introduce the periodic
Of course you’re going to need your endocrinologist
to make the decision whether this is clinical
trial type of intervention or they can actually
That is very tricky, so probably best, be
best to keep it within a clinical trial.
But you know, some endocrinologists may be
experienced enough to follow their own patients
and allow them to do it.
[Rhonda]: That’s very cool, I think that’s,
the fasting-mimicking diet being used as a
metabolic treatment for various diseases that
you just mentioned.
Obviously many of them need to be under the
care of a physician.
Is a very promising field because, you know,
as we’re learning now, metabolism plays a
major role in not only, you know, causing
these diseases, but also in the treatment
and how some of them respond to treatment.
[Valter]: And again, is not just metabolism.
Really, we’re looking at the ability in evolved
self-repair mode, right?
So, I mean, almost every disease, let’s say
that you have high cholesterol, what do we
We block cholesterol synthesis, right?
But is that sophisticated?
Not very sophisticated, right?
And all, you know, say, the great majority
of the drugs are like that.
You know, if you have an autoimmune disorder,
you have something that blocks a cytokine
or a receptor.
Very unsophisticated, right?
So if there is, and I’m not sure that there
is, but it looks like there is.
If there is a self-repair mode that goes after
almost every damaged system, this is much
more than metabolic intervention, this really
deals with three billion years of learning
how to fix a liver.
Of course starting with bacteria, but the
process of autophagy started back then in
Now you’re using it to let’s say a muscle
cell that is insulin resistant, now you might
push it to undergo autophagy, mitophagy, etc.,
etc., and now just maybe that resistant cell
is no longer resistant, right?
So, that’s the power of this, I think, much
more than the metabolic, you know, pushing
the cell into a different metabolic state.
I think it’s pushing it into a different metabolic
state while it’s doing this reset.
[Rhonda]: Right, reset.
That’s a great way of explaining it.
The reset is probably what I’m most excited
about, is that they’re clearing away the damaged
cells and then rejuvenating or fixing things.
But I do, I quickly want to just mention,
because I do recall now one of your studies
that you, at least in the clinical studies
with the fasting-mimicking diet, I think you
were trying to look whether or not there was
some stem cell activation and there was sort
of a trend you had seen mesenchymal stem cells
are trying to…you know, increasing them,
but are you looking…is that something now
you’re moving forward with, and are there
clinical studies to look at?
Now, yeah, we’re looking at that.
I mean, of course we never took biopsies.
I always feel bad about taking people’s biopsies
because it’s very painful usually to take
So we had blood and it’s not so easy to measure
stem, circulating stem cells.
I mean, now, techniques are getting better,
and so I think hopefully now we can have a
better look at the circulating one, but yeah,
we’re definitely going to look at…I think
in the trial that we’re now doing, athletes,
we’re doing a trial with athletes in University
of Verona in Italy, I think as part of that,
we have biopsies, muscle biopsy.
And so that should give us a better idea about
at least some tissue, associated stem cells,
satellite cells for example.
[Rhonda]: I’m so excited.
I’ll definitely be following your research.
Thank you so much Valter for the discussion
and your, talking about your book, “The Longevity
I look forward to talking to you some more.
[Valter]: Yeah, yeah.
Thank you for all the very good questions.