Oxygen, antioxidants: Does the oxygen that keeps us alive slowly kill us too?

. I have always been curious about the term antioxidants. Free radicals are what they fight against I'm told.

But oxygen is what keeps us alive, so an antioxidant is good for you, flavonoids and such. I'm an idiot when it comes to science.

Does oxygen keep us alive and cause us death too?

If so, could another breathable chemical on another planet allow beings to grow to adulthood but not age, or die.

If I'm an idiot for asking this just tell me, I won't get offended.

Idiots are those who do not ask, 100% pure oxygen at 1 atmosphere, will kill you, with the mixture we breath now, what we evolved to breath, is okay, many people live to 80/90 these days, so it cannot be too bad!

a reply to: Rasalghul

Oxygen is highly reactive, and can be a catalyst that causes other compounds to break down (i.e. corrode, combust, and otherwise just break those compounds apart).

However, that's what makes it so useful as a way a complex living organism can metabolize energy. If it weren't so highly reactive, then it wouldn't be an efficient way of pulling energy from otherwise stable compounds.


In fact, prior to the oxygenation period in Earth's history that occurred about 2.3 Billion years ago (prior to a time when Earth's atmosphere had an abundance of free oxygen), most life on Earth would have found oxygen to be toxic and poisonous -- i.e., too reactive for that early life to survive. The life that did survive the oxygenation of the atmosphere could use that oxygen for much more efficient metabolic processes than the old anaerobic (non-oxygen) life -- which lead to much more complex life on earth, which eventually led to where we are now.

EDIT TO ADD:
...And welcome to ATS.

In a very basic sense yes it does. The oxygen reacts or oxidizes with other chemicals in our bodies, this is something the body does not want and tries to expel the oxidized materials.

a reply to: pikestaff
Cool, good point. So what is an antioxidant according to the scientific community?

a reply to: Nexttimemaybe

I figured as much. I bet somewhere in the universe is a planet with a breathable chemical that allows for at least a very long life, if not a never ending one( would have to be a big planet) making illness rare and murder or something violent the cause of death.

I theorize a lot. But I find it interesting, this specific theory of mine.

Yes, oxygen eventually oxidizes everything, especially us.

originally posted by: Rasalghul
. I have always been curious about the term antioxidants. Free radicals are what they fight against I'm told.

But oxygen is what keeps us alive, so an antioxidant is good for you, flavonoids and such. I'm an idiot when it comes to science.

Does oxygen keep us alive and cause us death too?

If so, could another breathable chemical on another planet allow beings to grow to adulthood but not age, or die.

If I'm an idiot for asking this just tell me, I won't get offended.

Too much of anything will harm you.

We are not a single 'thing' we are a grouping of many things, a colony of cells, constantly replicating, growing and dying.

What we call our life is actually a balance of living and dying.

Consider a cancerous cell, it has a defect where apoptosis (programmed cell death) does not occur. The cells replicate to the point where their population swamps the balance of our bodies, causing illness and potentially our death.

So, we know that from a chemical perspective, excess Oxygen binds very easily to our Carbon based biology, causing damage and death to our cells.

Studies (such as this one) have suggested that a lower Oxygen uptake may increase lifespan and other studies that oxidative stress causes symptoms of aging. Be aware, though that there are dissenting views and studies, so we may not yet have the full picture.

originally posted by: Rasalghul
Does oxygen keep us alive and cause us death too?

I don't know if you know anything about cars, but an analogy I'd use is optimizing the fuel to air mixture for an internal combustion engine. The air of course contains oxygen. Too much air mixed with the fuel is bad. Too little air mixed with the fuel is bad. What you want is just the right amount.

So oxygen isn't good or bad, too much or too little of it is bad for biological machines like people or mechanical machines like combustion engines. And that's not just true of oxygen, it applies to many things.

Take dihydrogen monoxide for example. Too little is bad because you need a certain amount of it to live. Too much is bad and in fact too much dihydrogen monoxide kills thousands more people each year than carbon monoxide. That's why campaigns to ban DHMO are stupid, even though too much will kill us, we need a certain amount of it.

Take Iron, if you have too little you're anemic, too much and it's toxic..

So most substances we need, including oxygen, iron, dihydrogen monoxide (DHMO), etc, are a matter of getting the optimal amount where and when we need it, and not too much where we don't.

originally posted by: Rasalghul
a reply to: Nexttimemaybe

I figured as much. I bet somewhere in the universe is a planet with a breathable chemical that allows for at least a very long life, if not a never ending one( would have to be a big planet) making illness rare..

Still, a compound or element that is reactive enough (such as oxygen) for complex organism's efficient metabolism will be reactive enough to eventually break an organism down.

It's a double-edges sword.

a reply to: chr0naut

I've always believed in balance and moderation, so that makes perfect sense. Thanks for the info!

a reply to: Rasalghul

From my understanding, yes, oxygen does slowly kill us. Like others have pointed out, oxygen is highly combustible, which is what makes it so useful for our bodies to produce energy in the mitocondria. It constantly destroys our bodies from the inside out and we are always repairing the damage done.. it's called oxidative stress, and eventually it catches up though as we age .

Oxygen is killing us slowly

a reply to: pikestaff

no - 100% oxygen will not kill you - divers use 100% oxygen for decompression stops at < 10m [ less that 2 bar absolute pressure ]

NASA spacesuits are 100% oxygen. They pre breath for 2 hours and 20 minutes before a space walk. The first 50 minutes at 14.7 psi, normal sea level air pressure.

a reply to: LostWoods

Thanks. I understand better now. Im going to be drinking a lot of coffee, green tea and a glass of red wine every night, I want to live a long time.

At one point, it was believed that oxidation was the cause of aging. That's pretty much shot. Anti-oxidants may actually contribute to aging, by down regulating repair mechanisms.

Way Way Way too much oxygen can cause death. You're not very susceptible to oxygen poisoning at STP though.

a reply to: Bedlam

I thought antioxidants rid the body of free radicals? Is that not true? I mean antioxidants are in vitamins, and are advertised as beneficial to your health.

I've also read that many people who live 100+ years insist it's a daily glass of wine and a very basic diet that has led to their longevity.

a reply to: Rasalghul

the way to get to age 100 is :

dont die in the first 100 years

simples

Don't blame Oxygen!

Blame the sun it's really all the suns fault well that and our ozone layer ain't what it used to be...

Thank God for all the pyramids that cover the earth and the electromagnetic shield our wonderful ionosphere!

Oops...I thought you knew that how it got there...

originally posted by: Rasalghul
a reply to: Bedlam

I thought antioxidants rid the body of free radicals? Is that not true? I mean antioxidants are in vitamins, and are advertised as beneficial to your health.

I've also read that many people who live 100+ years insist it's a daily glass of wine and a very basic diet that has led to their longevity.

Wine isn't the same as vitamin E or whatever.

Go look at the latest results on antioxidants and aging. You actually live a significantly shorter lifespan on them.

Whereas, if you either stimulate the replacement of mitochondria or replace NAD+, you can live for maybe 3x your normal lifespan, even if you don't extend your telomeres.