Anti-Oxidant / Reductant

[Hethrir]

This has been bothering me for many years, and I must ask...why does the media constantly talk about food/drinks/wonder medicines as having anti-oxidants in them? When I did chemistry in school years ago, I was taught that a reductant counters an oxidant/free radical - has something changed, or is it a misquote to save teaching a new term?

[wautd]

There are different kind of anti-oxidants. They all delay oxidation but all use a different mechanism. (eg oxygen scavengers, chelators, free radical quelchers). In foods you got your fatty acids that will oxidize (which means you'll get free radicals)

[Admiral Valdemar]

The balance isn't kept, and even if enough reducers were present, they may not be able to compensate for the free radicals that readily attack the genomes of cells etc. It's similar to radiation, the cells can sustain only so much damage before they are overwhelmed, and so too many reactive oxygen species in the body and too little anti-oxidants means bad things.

[Hethrir]

I don't think I phrased the question right, is there a difference between an anti-oxidant and a reductant?

[wautd]

I don't think I phrased the question right, is there a difference between an anti-oxidant and a reductant?

I believe they are the synonyms

[wautd]

I don't think I phrased the question right, is there a difference between an anti-oxidant and a reductant?

I believe they are the synonyms

or it's like: all reductants are antioxidants but not all antioxidants are reductans

[tharkûn]

"Antioxidant" is not well defined, it is one of those terms that emerged in the early days of "biochemistry" and has been used ever since. My personal favorite defintion is: a substance that, when present at low concentrations compared with those of an oxidizable substrate, significantly delays or prevents oxidation of that substrate. Thus an antioxidant need not be a reductant; it could merely be something which sequesters substrates to delay oxidation. Conversely most reductants do not meet the concentration requirements which is why we don't count plenty of reductants in the diet as antioxidants.

Other definitions exist, some of which are quite terrible being coined by dead men who hadn't the foggiest clue about real biochemistry, but the above is the general gist of the good ones.

[Trytostaydead]

The balance isn't kept, and even if enough reducers were present, they may not be able to compensate for the free radicals that readily attack the genomes of cells etc. It's similar to radiation, the cells can sustain only so much damage before they are overwhelmed, and so too many reactive oxygen species in the body and too little anti-oxidants means bad things.

Or the more immediate effects it has on the cell before it even hits the genomes. Losing irreplaceable cells can just be as bad as fucking around with the genome.

[HemlockGrey]

I always loved talking about free radicals in Chem class. I was an endless fount of Lenin/Che/Castro jokes.

[Hethrir]

Thus an antioxidant need not be a reductant; it could merely be something which sequesters substrates to delay oxidation. Conversely most reductants do not meet the concentration requirements which is why we don't count plenty of reductants in the diet as antioxidants.

In that case, wouldn't it be more beneficial to have reducers in your diet in proper dosages than anti-oxidants?

[wautd]

Thus an antioxidant need not be a reductant; it could merely be something which sequesters substrates to delay oxidation. Conversely most reductants do not meet the concentration requirements which is why we don't count plenty of reductants in the diet as antioxidants.

In that case, wouldn't it be more beneficial to have reducers in your diet in proper dosages than anti-oxidants?

Apart for in vivo benefits, antioxidants can also be used to increase the shelf life of your food (delay of rancidity or colourloss)