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.
Antioxidants May Make Cancer Worse
21–30 of 42 posts
Re: Antioxidants May Make Cancer Worse
#22As 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.
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 the…
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
Re: Antioxidants May Make Cancer Worse
#23The 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...
Re: Antioxidants May Make Cancer Worse
#24Years 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.
Re: Antioxidants May Make Cancer Worse
#25Hilariously, 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.
Re: Antioxidants May Make Cancer Worse
#26What 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.
Re: Antioxidants May Make Cancer Worse
#27This 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.
Re: Antioxidants May Make Cancer Worse
#28What 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, r…
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).
Re: Antioxidants May Make Cancer Worse
#29The 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).
Homeostasis is why reducing dietary cholesterol doesn't do squat either. Reduce your intake and your body just makes more.
Re: Antioxidants May Make Cancer Worse
#30Many 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
[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...