Why are they beneficial when we need oxygen to survive? Do they even exist, or is it a marketing buzzword?
In: Biology
Oxygen is useful to your body because it is very reactive. Think about it like your car: your car needs gas to go, but that doesn’t mean you want to just pour gasoline all over your engine.
In particular, oxygen can undergo a small chemical reaction in your cells that makes it somewhat dangerous and allows it to easily cause damage to important machinery or even your DNA, which can cause cancer. Anti-oxidants don’t just slurp up any oxygen, but particularly react with this dangerous form, rendering it safe. This means that anti-oxidants can slow down cell death and damage slightly. But the benefit of anti-oxidants in your diet is fairly small overall.
They can exist and be a marketing buzzword at the same time.
Example: vitamins. If you don’t have vitamins, you die. But vitamin supplements have not been shown to do anything for most people. And yet, people still buy vitamin supplements.
Vitamins are real and have real defined health benefits. But the vitamin industry is at best a waste of money and at worst can active cause health issues if taken incorrectly.
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To explain that, I must explain something called a “free radical”. These are atoms or molecules in the body that have an unpaired electron. Think of electrons in atoms as dancers, they like to have a partner. If some atoms have an unpaired electron, they can take one from another atom. This exchange of electrons is called a “reduction oxidation reaction” or redox reaction for short. The atom or molecule that gains an electron is called an oxidizing agent or oxidant.
In some cases, the body uses these for various functions. However, too many can start to damage the body, perhaps even DNA, as those radicals start looking to get their electron a partner.
This is where antioxidants come in. They have electrons to spare and can donate them to satisfy the free radical. They are “anti-oxidant” because they safely neutralize them in a redox reaction
Antioxidants have nothing to do with oxygen. Well, it’s unrelated to the molecule at least. An oxidizer is an atom or molecule that accepts free electrons in a chemical reaction, and the most famous oxidizer is, well, oxygen, which is why it’s called that. Oxygen has two free valence electron spots, ready and eager to accept another electron to fill that spot. In fact, the only element that’s a better oxidizer is fluorine. An oxygen molecule has two oxygen atoms that are double bonded, sharing two electrons with each other allowing it to be more stable than it otherwise would be. It’s still not the most stable since each oxygen wants those electrons all to themselves, and this makes it a fantastic oxidizer: it readily accepts electrons from other atoms that don’t care about giving them up. This is basically what fire/burning is, the release of energy as oxygen accepts new bonds that break the double bond it has with another oxygen atom. And in fact, oxygen is such an incredibly reactive and dangerous atom people forget that one time oxygen almost killed all life on earth. Even now too much will kill you. Oxygen is toxic. This all doesn’t really have much to do (directly) with what an antioxidant is.
When oxygen is alone, not in its molecular form, it is a free radical. There are others but in keeping with the naming convention and reality, they are the most common and problematic ones usually. It’s missing those two electrons, and it really *really* wants to get them back. So it’ll try and grab them from anything it can, and that includes your DNA. If it does bond to your DNA, that can cause problems up to and including cell death or cancer. In reality, this is not only oxygen, this is anything that wants to grab electrons off of something, which is called oxidation, and something that does it is an oxidant, or an oxidizer. So an antioxidant does the opposite. It prevents oxidation from happening. It does this by being a reducer, which means it has excess valence electrons. This allows it to “eat up” the free radicals, by encouraging them to bond with it, instead of the stuff you care about. When you eat stuff with a bunch of antioxidants in it, you’re basically preventing the oxidants from hurting you, but beware because too many antioxidants can be dangerous too. They really want to give up the electrons so they can damage you in very similar ways. It’s just that as life forms we produce free radicals all the time as a byproduct of living (breaking up oxygen molecules), we don’t generally produce a lot of antioxidants as a part of living
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