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.
Note: Not a medical professional, with associated caveats.
I don't know about this article specifically, but the importance of hormesis in medicine has come on fairly strongly in recent years. Specifically, that persistent, low-level damage to your cells and subsequent autophagy can actually reduce one's risk of various ailments. Antioxidants reduce the occurrence of this damage.
Supplements contain massive levels of antioxidants compared to foods. I wouldn't want to completely cut out, say, glutathione, because then you'd miss cruciferous vegetables, for instance.
I'm not a medical professional, but I think whole, healthy foods are generally good choices.
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.
The overwhelming majority of these studies study these effects only in pill/supplement form. It's unknown if whole foods with the same vitamins present the same problems. IIRC, there's research suggesting whole foods are superior to vitamin pills (though I don't recall off the top of my head.)
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.
I think it's fair so say the idea that ingesting more antioxidants will cause there to be more in your cells despite homeostasis can be fairly called overly reductionist science. Science reporting in this case failed by essentially taking a side before the experiments came in and not backtracking afterwards.
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.
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).
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.
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.
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:
> 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
I too have come to realise this. Many times when I have been eating well, good quality food with plenty of variety, I catch a heavy cold that puts me out of action for at least a couple of days. Other times I have eaten like crap for weeks at a time, living off of pizza and fast food, skipping meals, and been around sick people and still don't catch anything. I have seen this pattern repeat over and over throughout my life.
"Polyphenols in coffee have been shown to affect free radicals in vitro,[132] but there is no evidence that this effect occurs in humans. Polyphenol levels vary depending on how beans are roasted as well as for how long. As interpreted by the Linus Pauling Institute and the European Food Safety Authority, dietary polyphenols, such as those ingested by consuming coffee, have little or no direct antioxidant value following ingestion."
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...
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.
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.
Antioxidants play a role in absorbing free radicals, which are unpaired electrons sitting on organic compounds inside the cell.
Free radicals are not entirely stable, and are mutagenic when they attach and break the phosphate molecules in the backbone of DNA (possibly leading to cancer).[1] These are dangerous because they can form reaction chains, which break molecule after molecule before finding a resting state. The antioxidants tend to give a more-stable resting state for the free radical, which makes it easier for your body to clear it.
Hence if your body has enough free-radical fighting antioxidants, it is more equipped to metabolize cancer-causing compounds.
Distilled, the article basically offer the contention that:
>.... it “could be that while antioxidants might prevent DNA damage—and thus impede tumor initiation—once a tumor is established, antioxidants might facilitate the malignant behavior of cancer cells..."<
Then immediately says this:
>The medical advice for people at this point is tentative. More studies need to be done to bolster this hypothesis and understand exactly how antioxidants affect cancer cells in humans. <
My takeaway is this:
Antioxidants may help prevent the sorts of DNA damage that contribute to cancers forming...
Antioxidants may contribute to the health of cancer cells, once formed, in much the same way...but that's not certain yet, even though it certainly seems plausible...
In actual practice--everyday life--we have no idea at any given time whether we have active cancer cells growing in our body, or not...symptoms are what lead us to suspect that such is the case and seek medical advice...with certain types of cancer symptoms can take months, years, to appear...if the contention is true it's possible that people are going out of their way (with supplements), or being obsessive (with diet), all the while unknowingly contributing to their undoing...
I think I'll just keep eating a healthy blend of foods, avoid all supplements unless they've been prescribed because a diagnosed deficiency, and get plenty of exercise...
That link states, "While it’s true that the package of antioxidants, minerals, fiber, and other substances found naturally in fruits, vegetables, and whole grains helps prevent a variety of chronic diseases..."
However, has even that much been proven? We know eating fruits and vegetables is good for you, and we know that in vitro, antioxidants help prevent damage to cells from free radicals. But considering that experiments with antioxidant supplementation have failed, do we really know that it's the antioxidants in fruits and vegetables that make them good for you?
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.
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."
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.
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.
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).
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.
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].
[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.
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).
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."
41 comments
[ 3.5 ms ] story [ 87.3 ms ] threadI 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.
I don't know about this article specifically, but the importance of hormesis in medicine has come on fairly strongly in recent years. Specifically, that persistent, low-level damage to your cells and subsequent autophagy can actually reduce one's risk of various ailments. Antioxidants reduce the occurrence of this damage.
https://en.wikipedia.org/wiki/Hormesis
https://en.wikipedia.org/wiki/Autophagy
I'm not a medical professional, but I think whole, healthy foods are generally good choices.
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.
I highly recommend it if you don't mind the higher degree of technical content than your average popularizing science book
http://www.ncbi.nlm.nih.gov/pubmed/22342103
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.
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.
http://miceats.blogspot.com/
I too have come to realise this. Many times when I have been eating well, good quality food with plenty of variety, I catch a heavy cold that puts me out of action for at least a couple of days. Other times I have eaten like crap for weeks at a time, living off of pizza and fast food, skipping meals, and been around sick people and still don't catch anything. I have seen this pattern repeat over and over throughout my life.
https://en.wikipedia.org/wiki/Coffee#Health_and_pharmacology
It's very hard to trust health information you get from the news.
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... and disease prevention studies
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.
Free radicals are not entirely stable, and are mutagenic when they attach and break the phosphate molecules in the backbone of DNA (possibly leading to cancer).[1] These are dangerous because they can form reaction chains, which break molecule after molecule before finding a resting state. The antioxidants tend to give a more-stable resting state for the free radical, which makes it easier for your body to clear it.
Hence if your body has enough free-radical fighting antioxidants, it is more equipped to metabolize cancer-causing compounds.
[1] http://www.ijpsr.info/docs/IJPSR10-01-03-04.pdf
>.... it “could be that while antioxidants might prevent DNA damage—and thus impede tumor initiation—once a tumor is established, antioxidants might facilitate the malignant behavior of cancer cells..."<
Then immediately says this:
>The medical advice for people at this point is tentative. More studies need to be done to bolster this hypothesis and understand exactly how antioxidants affect cancer cells in humans. <
My takeaway is this:
Antioxidants may help prevent the sorts of DNA damage that contribute to cancers forming... Antioxidants may contribute to the health of cancer cells, once formed, in much the same way...but that's not certain yet, even though it certainly seems plausible...
In actual practice--everyday life--we have no idea at any given time whether we have active cancer cells growing in our body, or not...symptoms are what lead us to suspect that such is the case and seek medical advice...with certain types of cancer symptoms can take months, years, to appear...if the contention is true it's possible that people are going out of their way (with supplements), or being obsessive (with diet), all the while unknowingly contributing to their undoing...
I think I'll just keep eating a healthy blend of foods, avoid all supplements unless they've been prescribed because a diagnosed deficiency, and get plenty of exercise...
However, has even that much been proven? We know eating fruits and vegetables is good for you, and we know that in vitro, antioxidants help prevent damage to cells from free radicals. But considering that experiments with antioxidant supplementation have failed, do we really know that it's the antioxidants in fruits and vegetables that make them good for you?
"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...
[2] http://www.nature.com/articles/nature15726.epdf
Both of these guys have lived to quite advanced age though, so who knows anymore.
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.
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
[2] https://en.wikipedia.org/wiki/Anthocyanin
[3] 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...
In no way does the research suggest that the antioxidant characteristics of the molecules are what is causing the 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.
http://drpasswater.com/nutrition_library/carotenoids_intervi...