
Antioxidants May Make Cancer Worse - jrs235
http://www.scientificamerican.com/article/antioxidants-may-make-cancer-worse/
======
e40
Years ago (10ish) I read an article (that I've tried to find a few times
since, but failed) by a researcher that tried to find the studies that said
antioxidants were good for you. He traced stories and articles back to...
nothing. I think the first mention he found was in a popular magazine and it
had no data or research to back it up.

I really wish I could find that article again. I remember being fascinated by
it.

Just found this:

[http://www.hsph.harvard.edu/nutritionsource/antioxidants/#an...](http://www.hsph.harvard.edu/nutritionsource/antioxidants/#antioxidants)
and disease prevention studies

~~~
niels_olson
The basis of the observation that oxidative stress is hard on cells comes from
the observation that many cell lines fail to grow in standard conditions (20
C, atmospheric pressure, normal atmosphere), and that the oxygen tension in
most tissues is actually well below atmospheric. These same cell lines survive
when incubated in low oxygen conditions.

This sort of difference, 21% [O2] vs 3% [O2] is _massive_ to a biologic
system, but observable results show up in hours to days. The idea was that,
over a lifetime, similar oxidative stress, at far lower levels, would
necessarily build up in cells over a lifetime. However, certain disease
conditions, like G6PD deficiency, give us a window into human physiology with
limited antioxidant capacity and a moderately sized study in Sardinia has
shown they may actually have a somewhat lower cancer risk overall.

Antioxidants fall into the giant pool of "meh" for most issues.

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ferrari8608
The article just talks about antioxidant supplements being harmful, not
naturally occurring antioxidants from sources such as coffee. That's good.
Don't ruin coffee for me, please science.

I don't really understand the whole supplement craze. To me, it feels like
common sense not to megadose any particular thing, especially when you don't
understand the effects said thing can have on the body.

~~~
tomhoward
_To me, it feels like common sense not to megadose any particular thing,
especially when you don 't understand the effects said thing can have on the
body._

This is a great comment, and hits the nail on the head.

I've spent much of the past 10 years trying to understand and overcome a
somewhat mysterious fatigue illness that seems most likely to be a general
autoimmune condition.

One of the approaches I've tried along the way is to consume large amounts of
various supplements, including vitamins, minerals, amino acids and herbs
(basically, whatever was the latest thing I heard some convincing-sounding
"expert" recommend).

What I ended up realising was that any high-dose supplement intake might
initially make me feel better, but after a while it would actually make me
feel worse.

As I understand it now, having devoted a lot of time to researching and
experimenting with this, is that a deficiency in any nutrient is less to do
with a lack of it in the diet and more to do with the body's
ability/willingness to absorb and utilise it [1].

And so the more of any given nutrient that you try and shove into the body,
the more you actually throw it out of balance, as it now has to deal with an
excess of something it was already struggling with or resisting, as well the
increased presence of that nutrient relative to other important nutrients.

More recently I've had much better success at improving my condition by
learning how to match my nutrient intake to what my body actually needs and
can handle at any given time (via diet and very sparing, selective supplement
intake), and that seems to now have me on a steady path to full recovery.

[1] Sure there are many people in the world who are ill due to inadequate
intake of certain nutrients from their diet, but that's more of an issue in
poverty-stricken societies, as opposed to developed-world societies where most
people have access to healthy-enough diets yet many still suffer from chronic
illness.

~~~
Mz
I have spent 15 years fixing my health via similar means. I would be thrilled
if you would be so kind as to read my latest attempt at a health blog and
leave comments or otherwise give me feedback:

[http://miceats.blogspot.com/](http://miceats.blogspot.com/)

------
tokenadult
The article kindly submitted here has the date October 7, 2015, referring to a
study in _Science Translational Medicine_ , and just today a group-edited blog
post by Dr. Steven Novella on Science-Based Medicine[1] brings us up to date
on a very recent study published by _Nature_.[2] As Dr. Novella puts it,

"The study is based on the observation that with solid tumors, like melanoma,
there is frequent dissemination of cancer cells through the blood (metastasis)
but these cells are very inefficient at establishing a metastatic tumor. One
reason for this is the immune system using ROS to essentially kill metastatic
cells before they can be established. They found that cancer cells that do
establish tumors tend to have mutations that make them resistant to oxidative
stress.

"Most relevant to this topic, however, they found that in mice exogenous
antioxidants promoted distant metastasis. This suggests that if you have
cancer and you take antioxidants, your chance of developing metastases is
greater. Keep in mind most solid tumor are usually present for 2-3 years
before they are diagnosed, so the risk potentially exists even for those who
have not yet been diagnosed with cancer.

"This has alarming implications given the popularity of antioxidant
supplements."

[1] [https://www.sciencebasedmedicine.org/more-trouble-for-
antiox...](https://www.sciencebasedmedicine.org/more-trouble-for-
antioxidants/)

[2]
[http://www.nature.com/articles/nature15726.epdf](http://www.nature.com/articles/nature15726.epdf)

------
danarlow
Many plant-derived chemicals that are called "antioxidants" by the popular
press (e.g. catechins [1], anthocyanins [2], retinoids [3], etc.) have been
shown to kill some types of cancer cells in vitro and in animal models, but
_not_ because they function as antioxidants per se. Instead, it seems that
they modulate particular cell signalling pathways that regulate cell growth
and survival just like other targeted cancer drugs [4]. In other words, the
fact that these molecules can neutralize free radicals in vitro is irrelevant
to their mechanism of action. Treating all of these diverse chemicals as one
class, "antioxidants", just muddies the waters.

In fact, there are even some cases where an "antioxidant" molecule selectively
killed a type of cancer cell by _increasing_ oxidative stress inside cells,
the opposite of what you'd expect from the blanket label. For example, it was
recently shown that high doses of vitamin C selectively kill a type of
colorectal cancer cell, but the mechanism of action was actually that the
cells take up the oxidized form of vitamin C via a sugar transporter that
tends to be upregulated in cancer cells, and the vitamin C-derrived pro-
oxidant caused an oxidative stress signalling cascade that led to cell death
[5].

[1]
[https://en.wikipedia.org/wiki/Catechin](https://en.wikipedia.org/wiki/Catechin)

[2]
[https://en.wikipedia.org/wiki/Anthocyanin](https://en.wikipedia.org/wiki/Anthocyanin)

[3]
[https://en.wikipedia.org/wiki/Retinoid](https://en.wikipedia.org/wiki/Retinoid)

[4] A corollary is that, like other drugs, each of these chemicals that is
effective against some type of cancer probably won't necessarily work against
other types.

[5]
[http://science.sciencemag.org/content/early/2015/11/04/scien...](http://science.sciencemag.org/content/early/2015/11/04/science.aaa5004)

------
trhway
Being high-iron cells, cancer cells is supposedly more easily damaged by free
radicals (this is how artemisinin being super-peroxide works against cancer
and malaria), and one can see the logic that cancer cells can benefit
significantly from decreasing of oxidative stress, in particular by anti-
oxidants.

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jensen123
I read an interesting interview a while ago. Among other things it mentions
that "The beta-carotene that is produced synthetically is a single isomer -- a
very straight molecule called "all-trans" beta-carotene. Beta-carotene that is
found in nature frequently consists of both the straight "all-trans" molecule
and a variety of bent molecules that contain what are called "cis" double
bonds."

[http://drpasswater.com/nutrition_library/carotenoids_intervi...](http://drpasswater.com/nutrition_library/carotenoids_interview.html)

------
dnautics
Hilariously, James Watson has been sounding the bell on this for years
(possibly motivated by a rivalry with Linus Pauling, who was downing megadoses
of vitamin C at the end of his life). But nobody has been listening to Watson
because of the overt racism in his talks for most folks drowning out the
interesting parts. Of course, watson himself has been megadosing with
metformin to stay alive longer, and claims to have prophylactically prevented
prostate cancer in himself, though recently metformin has been shown to also
be problematic.

Both of these guys have lived to quite advanced age though, so who knows
anymore.

------
fffrad
What I find interesting is how everyone has already accepted that antioxidants
are amazing against cancer. Now with this information will be resisted and
fought, whether it is true or false.

Every health nut (or enthusiast) praised antioxidants and will hold on to the
belief because they already believed it for so long.

We don't believe in facts, we believe in whatever advertisers have exposed to
us everyday on tv, radio, internet, and so on.

~~~
jimrandomh
Wait, everyone accepted what now? Prior to reading this article, I was of the
belief that there had already been randomized controlled trials showing that
antioxidant supplements increased all-cause mortality, mostly from cancer, and
that this had a known mechanism (oxidative stress kills cancer cells more than
it kills regular cells).

------
ThomPete
As I am now on my second Melanoma (luckily stage 1) this article hit me right
in the stomach for some reason.

I kept looking to see if I am eating something wrong. So can someone with
better understanding of antioxidants explain if this is only via vitamin or if
it's specifically present in some types of food.

~~~
Symmetry
People have investigated antioxidants pretty thoroughly and supplemental
antioxidants really aren't needed in healthy cells. _Power, Sex, Suicide:
Mitochondria and the Meaning of Life_ goes into some details on the
biochemistry behind that but you can look at the Antioxidant Wikipedia page
for all the research showing no positive effect.

If I were to speculate it might be that while normal cells can make enough for
themselves cancerous cells benefit from external antioxidants. The damage done
by free radicals is mostly concentrated in the mitochondrial genome, which is
why evolution has brought as many genes as possible out of the mitochondria
into the nucleus. By contrast the mutations that causes cancer are, IIRC,
mostly inside the nucleus.

~~~
ploomans
I recently read the latest book of the same author on the same theme "The
Vital Question: Energy, Evolution, and the Origins of Complex Life".

I highly recommend it if you don't mind the higher degree of technical content
than your average popularizing science book

------
danieltillett
The problem is there are inducible antioxidant systems inside our cells. If
you increase the levels of exogenous antioxidants then your cells respond and
down regulate the inducible systems and you end up where you started
(homeostasis is a bitch).

~~~
Gibbon1
Homeostasis is why reducing dietary cholesterol doesn't do squat either.
Reduce your intake and your body just makes more.

------
bduerst
The title should have been "Some molecules, which happen to be antioxidants,
may cause cancer".

In no way does the research suggest that the antioxidant characteristics of
the molecules are what is causing the cancer.

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autodidacticon
This research seems to indicate that if you already have cancer, antioxidants
may accelerate its growth. It doesn't address the commonly held belief that
antioxidants prevent cancer.

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SocksCanClose
Cue the, "Half of everything we know about medicine is wrong... we just don't
know which half."

~~~
kevin_thibedeau
You sound just like a PBS infomercial. Where do I get your book and sign up
for your newsletter.

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SocksCanClose
cf "Adecade ago, I stood alongside my 99 fellow freshmen as we were welcomed
into the ranks of medicine in a ''white coat ceremony.'' Here, on our first
day of med school, we were presented with the short white coats that
proclaimed us part of the mystery and the discipline of medicine. During that
ceremony, the dean said something that was repeated throughout my education:
half of what we teach you here is wrong -- unfortunately, we don't know which
half." via
[http://www.nytimes.com/2003/03/16/magazine/16INTRO.html?page...](http://www.nytimes.com/2003/03/16/magazine/16INTRO.html?pagewanted=all)

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baconforce
Like a shipment of weapons sent to a castle to help defend it from outside
forces. Makes sense when the castle is occupied by the good guys, but when
occupied by the bad guys (cancer) it only strengthens them.

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pyre
I remember reading a comment somewhere (HN? Slashdot?) years ago that talking
about the mechanisms behind antioxidants. The gist was that antioxidants would
help prevent cancer, up until the point where cancer manifests itself. After
that, it would actually _help_ cancer.

Note that the comment was speaking from a critical thinking perspective about
the way cancer works and the way that the antioxidants work in the body (not
from actual study results).

So this doesn't seem so surprising to me.

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dschiptsov
Like any other poorly understood interventions into vastly complex, self-
balancing ecosystems.

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bad_user
Reductionist science does it again.

~~~
mmaunder
Yup. The trouble with this kind of linkbaity content is that it makes you dive
for the pill bottle or the juicer and consume even more high concentrations of
something our species never evolved into handling.

~~~
vvpan
Or in this case the opposite.

