Study: Some Antioxidants Could Increase Cancer Rates

sciencehabit writes "Many people take vitamins such as A, E, and C thinking that their antioxidant properties will ward off cancer. But some clinical trials have suggested that such antioxidants, which sop up DNA-damaging molecules called free radicals, have the opposite effect and raise cancer risk in certain people. Now, in a provocative study that raises unsettling questions about the widespread use of vitamin supplements, Swedish researchers have showed that moderate doses of two widely used antioxidants spur the growth of early lung tumors in mice."

Comments

Not very surprising.

[Ihlosi]

Oxidizing compounds (like H2O2) are one of the forms of "ammunition" the immune system has. Too many antioxidants in the body will make this weapon less effective.

Also, cancer cells are more susceptive to oxidative damage due to their generally higher cell division rate. This is also why ionizing radiation usually damages cancer cells more than regular cells.

Re:Not very surprising.

[fuzzyfuzzyfungus]

I think people labor under the delusion that 'health' is some sort of idyllic state of bodily perfection, rather than the state where most of the potentially catastrophic pathogens, precancerous cells, and who knows what else are being held in enough of a stalemate that something else will probably kill you first.

In the totally contra-factual world where your body exists in edenic good health until malign external influences crop up, tamping down a dangerous-but-effective system seems like a much better idea.

Re:Not very surprising.

[Ihlosi]

Probably misremembering this, but aren't cancer cells often under higher oxidative stress to begin with, too?

They are more susceptible to oxidative damage since they spend more time in the various stages of cell division (where the DNA is especially vulnerable to oxidative damage) than regular cells (which spend most of their time not actively dividing, where their DNA is less prone to being irreparably damaged by oxidizing compounds).

However, fast-growing cancer sometimes has the nasty habit of out-growing its network of blood vessels, creating areas of the tumor that are oxygen deprived and therefore hard to damage by using ionizing radiation.

Re:Not very surprising.

[Rosco P. Coltrane]

Look at it another way: evolution gave human beings their big brain, which allows them to invent stuff to live longer. If humans of the future live to a ripe old age because they've invented a cure for cancer, prosthetics for failing organs, and drugs for many ailments that afflict aging, undaided humans, well *that*'s evolution!

We're the first species that has evolved enough to escape, or rather accelerate evolution itself. Just like dairy cows and race horses, we're becoming designer beings. Only instead of designing other animals, we're designing ourselves. That's a lot more exciting than submitting to the blind laws of nature, that work very very slowly by elimination, don't you think?

Re:Not very surprising.

[Rosco P. Coltrane]

I think people labor under the delusion that 'health' is some sort of idyllic state of bodily perfection, rather than the state where most of the potentially catastrophic pathogens, precancerous cells, and who knows what else are being held in enough of a stalemate that something else will probably kill you first.

Well that's pretty much what life itself is: it's a process that tries to fight entropy for as long as possible, but always gets overwhelmed in the end no matter what.

I've read somewhere that people (and animals, and plants) get cancer all the time in the form of cells that have mutated or divided erroneously, but their body always manages to get rid of the misfit cells. But over time, the faulty cells get faulty in nastier ways, or become more numerous, and manage to overwhelm the immune system.

Re:Not very surprising.

[Anonymous Coward]

If the tumor is O2 deprived wouldn't that slow down cell division which would make it slow growing?

Regrettably, cancer cells usually have no problem generating the energy for sustained cell divisions entirely without oxygen. They can use oxygen if it's available, but they're not dependent on it.

http://en.wikipedia.org/wiki/Warburg_effect

Re:Yes, but...

[Anonymous Coward]

Since when sentences need verbs?

Re:kids these days

[daem0n1x]

we should stop putting unnatural things into our bodies that should only be enjoying god's creations

Yeah, all the great things god created, like Mycobacterium tuberculosis, Clostridium tetani, Variola virus, Poliovirus, let's put all that stuff in our bodies, not those evil vaccine things!

Why supplements?

[daem0n1x]

Supplements are just one more useless thing that businesses convince people they need. The only ones that need them are businesses, to make shitloads of money.

If you have a varied and balanced diet and don't suffer from any condition that makes you need a reinforced dose of any particular nutrient, you don't need any dietary supplements.

Eat properly and exercise! It's easier, cheaper, and it works.

Re:Trust me?

[gnoshi]

Well, since this is consistent with findings of previous studies which were not specifically looking for this - for example, a Vitamin E supplement trial which was called off early due to the high cancer rates in the active drug group (http://www.cancer.org/cancer/news/news/major-study-of-supplements-and-prostate-cancer-halted) - I'd say that this result is correct.
Of course, maybe that researcher was on the take too, right?

Re:Stop!

[ledow]

If you're eating in any way sensibly, you should have no need of extraneous vitamin supplements anyway.

There are certain conditions (either genetic or self-imposed, like veganism) where you don't get all that's required - and then you need to get a nutritionist on the case, not just buy things in dosages you have no clue of and take 100% RDA of on top of your normal diet.

It's an RDA for a reason. Not only is it a suggested (not absolute) minimum, but also a suggested maximum too. People miss the fact that anything other that can potentially be damaging (there's not been much study into it, but if X amount of a certain vitamin shows that you're healthiest and "plateaus" around that usage, why would you need to take more?) in the same way as lack of it.

And, with stuff like vitamins, it's not instantaneous results, so you can't correlate it with whether you feel better or not or got sick or not directly. In the same way that it will take you time to notice you don't have enough (say) iron in your diet, it might take you longer to notice that you have too much.

Your body is a machine that's honed by evolution. Eat well, eat properly, eat what it has evolved to eat (which includes meat!) and the amount it has evolved to cope with. And then you'll be fine.

Umm, don't you mean

[Maury Markowitz]

"Now, in a provocative study that raises unsettling questions about the widespread use of vitamin supplements"

I believe that should be worded, "Now *another* provocative study" After all, there's been a continuous stream of these. For whatever reason, the human body doesn't like being dosed with massive amounts of chemically reactive substances, gee, what a surprise.

You can get the same dose from eating fruit, but that has no known downsides in multiple studies. If you're worried about your health, eat your fruit and veg - like they've been saying forever,

Re:kids these days

[NotQuiteReal]

Heh, reminds me of an oldie, but a goodie -

All things dull and ugly,
All creatures short and squat,
All things rude and nasty,
The Lord God made the lot;

Each little snake that poisons,
Each little wasp that stings,
He made their brutish venom,
He made their horrid wings.

All things sick and cancerous,
All evil great and small,
All things foul and dangerous,
The Lord God made them all.

Each nasty little hornet,
Each beastly little squid.
Who made the spikey urchin?
Who made the sharks? He did.

All things scabbed and ulcerous,
All pox both great and small.
Putrid, foul and gangrenous,
The Lord God made them all.

-- Monty Python