
Scientists narrow down the mechanism whereby cancer cells metabolise sugar - eloff
https://www.sciencealert.com/a-nine-year-study-has-just-shown-how-sugar-exacerbates-cancer
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abainbridge
It seems to me that "sugar" is a very vague term. Fructose and glucose are
very different. For example their glycemic indices are 19 and 100
respectively, yet they are both sugars.

Is it reasonable to talk about the health impact of sugar at all? For example,
the article says:

> This link between sugar and cancer has sweeping consequences.

Does that refer to sugar I eat? Or sugar my body makes from carbohydrates I
eat? And are glucose and fructose equally linked to cancer? What about all the
other sugars?

~~~
DiThi
GI measures glucose, so it makes sense that a substance that is not glucose
has less GI than glucose itself. However that doesn't mean fructose alone is
better than glucose. In fact it's much, much worse.

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sgt101
do you have more material on that so I can understand?

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DiThi
[https://www.youtube.com/watch?v=f_4Q9Iv7_Ao](https://www.youtube.com/watch?v=f_4Q9Iv7_Ao)

I also recommend the rest of the channel.

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Krabbey
> The team used yeast cells for its research – specifically looking at the
> 'Ras' gene family, a family of genes that is present in all animal cells,
> including human cancer cells.

Hmm.. So they could have used any opisthokont's cells for a model, but they
chose a fungus, a type of organism that travels readily in the environment as
micrometer-sized spores and on even forms yeast, a zoomorphism which just so
happens to match the growth and feeding patterns of cancer.. makes sense.

~~~
tamcap
They chose yeast because a lot of the basic eukaryotic biology is conserved
(as compared to humans) and it's basically free to grow more yeast quickly.
This means you can run your experiments super fast.

Conversely, the above has resulted in a big number of yeast trained molecular
biologists, who end up applying yeast work wherever they can (see: law of the
instrument). Sometimes it works, sometimes it doesn't.

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bgitarts
Can cancer cells metabolise ketones?

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tertius
Remember that "cancer" is just normal cells that grow out of control. So if
your normal cells are functioning normally then cancer cells will also
function normally. If ketosis stopped cancer cells from proliferating the same
would go for all other normal cells of the specific tissue.

Ketosis has shown to be good for quicker recovery from chemotherapy.

~~~
jpfed
>Remember that "cancer" is just normal cells that grow out of control. So if
your normal cells are functioning normally then cancer cells will also
function normally.

But that only holds if growing out of control has no impact on normal
function. If, say, cancer cells reproduced faster than their own mitochondria,
then those cancer cells would function differently from normal cells in a
particular sense: they could metabolize sugars into pyruvate but not all the
way to CO2 + H2O. And that in turn could have other consequences.

~~~
tertius
True. I was only referencing what they use as energy, i.e. the same sugars
(etc.) that their normal growing and dying counterparts do.

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aceon48
Ugh can we just put AlphaGo deep learning on diet / cancer/ food studies? One
week meats are bad, next week meats are great dont eat carbs!

I'm getting javascript framework diet fad of the week fatigue

~~~
jmcqk6
>One week meats are bad, next week meats are great dont eat carbs

I don't think this is a problem with our learning, but a problem with our
unrelenting desire to compress complex subjects and findings into easily
digestible morsels that people can understand without too much thought.

Deep learning isn't going to help with that.

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philfrasty
This research is getting misused badly and is a very lucrative business
selling to cancer patients in the „alternative medicine“ sector.

I lost my uncle last year to small-cell lung cancer (age 40). Doctors gave him
12 months after the diagnosis, turns out he barely had 3 months (mostly due to
a very bad response to chemotherapy). In his last months he turned to one of
these alternative medicine gurus who told him that the tumor (quote) „would
eat itself“ if he stops eating sugars.

~~~
echelon
Was your uncle a smoker or otherwise at risk? Is this something anyone can
get? It sounds terrifying to realize you have that little time left at such a
young age.

Sorry if this is too personal of a question.

~~~
fpoling
Unfortunately anyone can get cancer at any age. Body gets thousands of
cancerous cells daily. Typically it is not a problem as those cells are get
killed by the immune system. The problem starts when those cells stuck and
starts to multiply. But even then it may takes many years before the growth
can be detected and starts to affect health. A person can get a cancer from
single exposure to a highly carcinogenic factor and get cancer as sickness 20
years later.

The best one can do is try to minimize risk factors to either avoid cancerous
growth or at least to slow it down to the extent that it does not affect life
expectancy.

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hprotagonist
jesus that title's misleading.

THe actual paper is about the
[https://en.wikipedia.org/wiki/Warburg_effect](https://en.wikipedia.org/wiki/Warburg_effect)
Warburg effect (the observation that cancerous cells rely heavily on
glycolysis). People have wondered about causation, and this group has offered
some mechanistic answers that help get us closer to knowing if glycolysis
spikes _because_ you have cancer, or you get cancer because you lean on
glycolysis.

~~~
banachtarski
I read your post, and while the nuance is a bit different, it's not _that_
misleading relative to your understanding of it. And they cite the Warburg
effect plenty. I think showing that it is causative instead of correlative
_is_ in effect showing how sugar exacerbates cancer.

~~~
JPLeRouzic
As the GP, I do not think the title is correct. The Warburg effect does not
tell that sugar causes cancer, it tells that cancer cells prefer one of the
two mechanisms to create ATP.

This mechanism is the glycolysis (something used in fermentation), which is
much less effective than the other mechanism which uses oxygen (used indeed in
respiration) to produce ATP.

From the article abstract, they hint that the cell cycle is quicker with
glycolyse than with respiration.

------
transverse
Study in question:

Fructose-1,6-bisphosphate couples glycolytic flux to activation of Ras (2017)

[https://www.nature.com/articles/s41467-017-01019-z](https://www.nature.com/articles/s41467-017-01019-z)

Background:
[https://en.wikipedia.org/wiki/Warburg_effect](https://en.wikipedia.org/wiki/Warburg_effect)

~~~
agumonkey
From what I recall (k)RAS gene is also a marker in incurable lung cancer
lines.

~~~
epmaybe
You are correct. However, this paper specifically only looks at H-RAS, also a
proto-oncogene.

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dk28
so the three major killers have one cause? Cancer, heart attacks and diabetes
are simply from overeating sugar and simple carbs

~~~
jlebrech
I thought it was protein [https://www.livescience.com/43839-too-much-protein-
help-canc...](https://www.livescience.com/43839-too-much-protein-help-cancers-
grow.html)

~~~
DiThi
Makes sense since excess protein is converted to glucose anyway. So
ultimately, too much protein equals too much carbs, plus a bit too much of
substances typical of mass farming.

~~~
jlebrech
Too much of any macronutrient causes a negative effect.

~~~
DiThi
The amount of "too much" for fat is however greater than for the other two,
and for most people it's difficult to overeat willingly with fat.

~~~
jlebrech
i'm also unsure how much is too much, but fat does affect insulin sensitivity

the issue would be to reduce fat consumption as much as humanly possible,
while taking regular blood sugar measurement, only diabetics do this and it's
already late by then.

[https://www.ncbi.nlm.nih.gov/pubmed/15297079](https://www.ncbi.nlm.nih.gov/pubmed/15297079)

~~~
DiThi
The abstract of that study doesn't mention carbs. That's a very important
detail. If you're eating a "normal" amount of carbs (like in the vast majority
of studies of this type, even "low" can mean 25%), it is true that saturated
fat makes it worse. But in other studies it has been shown to be the opposite
with a fully ketogenic diet, i.e. when the body can't make glucose from carbs
or protein and resorts to fat instead. Insulin _must_ be low for ketosis to
happen. Insulin is also triggered by low sodium.

I cannot find a single study showing insuline resistance due to high fat
consumption when consuming <5% of calories in carbs and <25% in protein.

~~~
jlebrech
it mentions insulin a lot, and you cannot metabolise carbs without it.

~~~
DiThi
During ketosis there's barely any carbs to metabolize anyway. That's why I
mention carbs at all: they cause the problem and saturated fat just makes the
problem worse. A lot of these studies (esp the ones more than a decade old)
show this correlation and makes the mistake to attribute the problem to fat.

Our ancestors only found carbs accompanied by lots of fiber. Fiber causes
satiety. Carbs cause insulin secretion, which indirectly converts carbs to fat
and puts the body in fat storage mode. Storing fat was an advantage to our
ancestors because they couldn't ever store fat all year round. But nowadays
30% of calories in carbs is considered "normal" or even "low", but it's
actually absurdly high considering the rest of the diet (low fiber, way too
much fructose) and our activity.

