Talk:Antioxidant/Archive 1

message: An article from Food Production Daily  from May 9, 2005 asserts that a 3oz serving of button mushrooms offers 5 milligrams of ergothioneine, or 12 times the antioxidant of wheat germ.  Exotic mushrooms such as shiitake, oyster, or maitake can containe 40 times the antioxidant of wheat germ.  This finding was the result of a new assay developed at Penn State that uses traditional analytical chemistry techniques and is transferable to the analysis of other plants, not just mushrooms.
--208.50.113.34 13:37, 16 September 2005 (UTC)
thread_title: Food Production Daily

message: In the intro, the article states that an antioxidant is any chemical that prevents oxidation, but the rest of the article treats antioxidants as nutritional supplements, even referring to dosages in the "types" section. Should we perhaps have a separate section or article on antioxidants as nutritional suplements? Shaggorama 10:16, 2 January 2006 (UTC)
thread_title:  Article too focused? 

message: Big reorgs make me uncomfortable, it's difficult to watch which changes are being made to the article. I would ask that if this is done, that the creation of new sections and shifting of paragraphs be done in their own edits. Then, if you want to alter the CONTENTS of the paragraph, it be done as a separate edit. I wish wiki had a way of negating the red and drawing arrows showing paragraph movements. I realize that would be difficult, but it should be possible, and help reduce confusion and shock at large reorganizations. During them, information can slip in and out. You realize why, for those watching the community, this is hard? Tyciol 19:51, 17 January 2006 (UTC)
thread_title:  Big Reorganization 

message: :Fear not, everything that all y'all wrote is still in the article, but I couldn't help myself and had to do a massive reorg.  The *information* in the article was professional, but the *structure* of the article was amateurish.  I still left the Cleanup-Date tag that produces "This article may require cleanup" at the top of the article, because there are still many loose ends and rambling thoughts without references (including my own).  Can someone who is chemically knowledgeable put the straggler antioxidants such as the saponins, tannin polymers, and plant pigments, in their appropriate categories, or, if they are NOT antioxidants, remove them from the article?  Thanks.  N3362 04:19, 10 April 2006 (UTC)
replies: text: Nice work - this has added a lot more detail on the value of different foods. In accordance with wikipedia guidance, I have done a small amount of pruning that has not removed any factual content. Elroch 02:16, 12 April 2006 (UTC)
thread_title:  Article reorganized, and ALL previous work preserved 

message: I felt that this article was quite one-sided, so I'm the first to add parts mentioning the antinutrient and toxic effects of certain dietary antioxidants.
Zymatik 07:07, 13 April 2006 (UTC)
thread_title:  Health hazards 

message: The use of polymers in non-biological contexts is certainly of interest (but most would agree of less broad interest than their biological role). However, there is no reason to leave empty headings near the top of this article to remind editors of this fact. If someone does want to write these sections, the headings for empty sections that I removed are:
:::==Antioxidants in polymer industry==
:::==Antioxidant in fuel stabilisation==
Elroch 21:26, 21 April 2006 (UTC)
thread_title:  Non-biology sections need to be written 

message: The introductory sections relating to the biological role of antioxidants have possibly the highest potential impact of any in this quite lengthy article, since that is what the largest number of readers actually read. In light of this, the first paragraph might be expanded. The "Mechanism" section in particular is rather poor, giving a very patchy and incomplete picture. It would be useful if someone with a thorough knowledge of biology, and the inclination to present material in an accessible way, reworked the early sections. Elroch 21:37, 21 April 2006 (UTC)
thread_title: Introductory sections

message: I am guessing that there must be at least 300 extraordinary food sources of antioxidant chemicals. It is beyond the scope of this article to provide long descriptions of each editor's favorite antioxidant food source and its health benefits (health benefit descriptions are redundant, since they are already covered elsewhere in the article). There was a section named Antioxidants in walnuts (saved below). I copied several of its most pertinent points into a condensed description of walnut appearing elsewhere in the article, and then I deleted that section; parts of which more appropriately belong in the articles named walnut, and flavonoid, and tannin:
Antioxidants in walnuts
Analyses of walnut extracts show that walnuts:
Are the only nut containing high quantities of ellagic acid.
Are unique among the edible tree nuts because of their high content of omega-3 polyunsaturated linoleic and linolenic fatty acids.  These fatty acids are short-chain fatty acids that tend to oxidize easily, so the walnut has high quantities of antioxidants to protect itself (which results in protection of LDL oxidation in humans who eat them).
Have a high content of tocopherols (vitamin E) in the kernel, especially gamma tocopherol.
Have a high content of phenolic antioxidants.  These are what make the walnut taste bitter, and are found in the highest concentration in the pellicle. Some of these nonflavonoid phenolics are present as the monomers ellagic acid, gallic acid and methyl gallate, but most of these phenolics in the walnut are nonflavonoid phenolic polymers known as ellagitannins.  These are hydrolyzable tannins formed when phenolic monomers bind to sugar molecules and form polymers, such as valoneic acid dilactone and pedunculagin.
Contain at least one flavonol, related to quercetin.
Are potent inhibitors of plasma and LDL oxidation, (but only under certain circumstances).
The identities of all of the chemicals found in walnut extract, and their capacity and functionality as antioxidants, are still not completely known.  When walnut extract is compared to purified chemicals known to exist in the extract, the results sometimes seem to contradict each other (for example, extract has more antioxidant activity under some circumstances and less under other circumstances).
Consumption of walnuts improves one’s serum lipid profile:
Increases HDL cholesterol
Increases apolipoprotein
Decreases total and LDL cholesterol
Decreases triglycerides
Zymatik 18:24, 26 April 2006 (UTC)
thread_title: Long descriptions of particular nutritional sources

message: There is a strong case for separating antioxidants in living organisms and technological uses of antioxidants into two separate articles, with the main article being the biological one (based on what appears to be the large majority of readers), with a clear link at the top to an article on antioxidant technology. The role of antioxidants in chemistry and in food technology is important and could do with expansion, but it looks oddly out of place in the article as it stands, a bit like a discussion of combustion would be in an article on respiration. The historical material is rather anthropocentric - a balanced history would point out that antioxidants are believed to have been used as a protective mechanism by organisms since very early in the development of life, which predates rubber technology by about 2 billion years. My suggested title for the other article is simply antioxidant technology, as that would cover uses of antioxidants in chemistry and food technology. Has anyone else got any other suggestions for the title of the other article, or comments on this idea? Elroch 00:02, 1 May 2006 (UTC)
replies: text: I would oppose split at the current time although I can see a case for a split if the technological uses were ever expanded.  The concept of an "antioxidant" is, like all concepts in biology, an attempt by man to understand complex natural processes.  Thus I don't see how to separate it from chemistry that defines it, or to separate it from the history of how man came to define the term, and how the connotations have changed over the years as conceptions of nutrition and biology have changed.  Labeling phytochemicals and enzymes with a term as simplistic as "antioxidant" is anthropocentric regardless. I would rather think that the main article on antioxidant could use more emphasis the mechanisms by which antioxidants are thought (by people) to act in biology. I do agree that the evolutionary history of antioxidants would be very interesting -- except that very little is known about it. Prithason 02:08, 1 May 2006 (UTC)
replies: text: A very strong argument would be needed to outweigh the fact that biology and chemistry are different subjects. Elroch 11:45, 1 May 2006 (UTC)
thread_title: Suggested split of article

message: I moved this text here as it's had a request for verification for a while now with no improvement.
Coffee is often depleted of antioxidants due to the high-temperature roasting process.   The US FDA may have recently suggested that the average person should consume up to 7000 ORAC units daily, in order to reduce the risk of cancer.  As this is nearly 12 servings of high-ORAC-value fruit, the use of nutritional supplements containing bioflavonoids is likely necessary to reach this target. David.Throop 05:33, 27 May 2006 (UTC)
thread_title: Doubtful claims about coffee moved to Talk

message: The USDA chart listing the antioxidents of the top 20 foods looks wrong, because the foods do not have the same serving sizes. For example--(1) Small red beans, 1/2 cup dried beans, 13727; (2) Wild blueberry, 1 cup, 13427; (3) Red kidney beans, 1/2 cup dried beans 13259.  Shouldn't the wild blueberry's ammount be divided into half to arrive at 6,713.5. I suppose it's easier to talk about the antioxident of one plum, instead of a 1/2 cup of a plum, but, the 1/2 cup and 1 cup measurement should be either be all 1/2 cup or all 1 cup servings. I think the USDA could have made a better chart than this one. 204.80.61.10 16:48, 24 July 2006 (UTC)
thread_title: 20 foods serving sizes are not all the same

message: I have moved the following edits here so they can be discussed.  They do not belong in the article in their current form for the following reasons:
1.  The paragraph is discussing possible *harmful* effects of antioxidants. The original statements were already clearly stated as hypotheses, with a citation, not as proven fact.
2.  The statements are unsupported by the cites.  Neither Chendil et al nor Baatout et al make any claims in their papers that antioxidants work as sensitizers for radio- or chemotherapy.
3.  Any claim for strong evidence in the setting of effects on health must be based on clinical trials, not experiments on cell lines.
Prithason 05:01, 16 September 2006 (UTC)
replies: text: You can set the bar even higher than this.  You might want multiple trials in some areas.  We use this in the Alzheimer's disease page.  --Chrispounds 02:31, 27 November 2006 (UTC)
thread_title: Antioxidants and cancer chemotherapy

message: One thing this article needs is a better lead sentence.  I think the current one hits the reader with too much all ot once.  Any ideas on simplifying it? ike9898 15:47, 1 November 2006 (UTC)
thread_title:  lead sentence 

message: It would be good if an expert could go through the article and determine if all the chemicals discussed are in fact properly classified as antioxidants. It seems to me that while many of them counteract the action of free radicals, free radicals can also be reducing species. - Samsara (talk • contribs) 18:56, 14 November 2006 (UTC)
thread_title:  {{tl|expert}} 

message: The entire dietary supplements section is a big glorified list, not really appropriate for this article and dramatically under-cited. The "main article", List of phytochemicals and foods in which they are prominent, is a much more general list (itself uncited, but that's a separate problem). Any thoughts on moving the dietary stuff here to a subarticle, say Dietary sources of antioxidants or similar? Opabinia regalis 07:23, 25 November 2006 (UTC)
replies: text: One strategy would be to set a bar of scientific evidence necessary to be listed here.  Another subarticle can be more generous in describing the broader range of options.  --Chrispounds 02:29, 27 November 2006 (UTC)

text: If the benefits are mentioned or we think about relating this to a disease, we need to be very clear about the risks involved.  Vitamin E is not recommended in doses greater than 400 IU for those with CV risk factors, for example.  --Chrispounds 02:41, 27 November 2006 (UTC)
replies: text: The challenge here is that most of the chemicals mentioned really are antioxidants. I agree that "chemical X reduces the risk of disease Y" statements should have a high threshold for inclusion, but the dietary supplements section is just an undifferentiated list. Overall, what I'd rather see is that section moved (or removed entirely, it's not very useful as it stands) and replaced with a section that mentions only those for which major research has shown some benefit, as you suggest, accompanied by appropriate discussion of risks. A neutrally written section on the popularity/usefulness of 'antioxidant' products in the health food industry wouldn't go amiss either. Opabinia regalis 04:35, 27 November 2006 (UTC)

text: A general list of antioxidants in food is justified, so I have made this change, promoting the list to its own topic and reorg under antioxidants in food. MatthewEHarbowy 23:22, 1 December 2006 (UTC)
thread_title:  Dietary supplements section 

message: Hi Tim, just a question; did you mean to delete the propyl gallate and the abbreviations for the food preservatives?  I think many people will have heard of BHA and BHT from their cereal boxes, and might recognize them more than their proper chemical names.
The role of antioxidants in preserving cosmetics is perhaps a throwaway factoid, but it might be helpful in bringing home the message that all fat-based substances are apt to go rancid and can be protected with antioxidants.  People seem to think of antioxidants only in relation to health and food, but don't extrapolate that the same factors are at work in other areas, such as grease or whatnot.  Anyway, just a suggestion, Willow 22:02, 2 March 2007 (UTC)
replies: text: Oops, I hadn't realised I had. Added them back, my apologies. I moved the cosmetics to the industrial uses section, perhaps an unpleasant implication! TimVickers 22:41, 2 March 2007 (UTC)
thread_title: Gallic cosmetics? ;)

message: We certainly need a section on this, Sebastiano is quite right that this is a major omission from the article. This is what I would propose as an outline:
*Origin of life under reducing conditions.
*Oxygenic photosynthesis as the beginning of oxidative stress.
The evolution of oxygen-producing cells was probably one of the most significant events in the history of life. Protective endogenous antioxidant enzymes and exogenous dietary antioxidants [as Selenium and Iodine (I)] helped to prevent oxidative stress. When about 500 million years ago plants and animals began to transfer from the sea to rivers and land, environmental I-deficiency was a challenge to the evolution of terrestrial life. 
*Evolution of GSH, ascorbate and antioxidant enzymes, mention of iodine if particularly important in cyanobacteria?
Oxygen is a potent oxidant whose accumulation in terrestrial atmosphere resulted from the development of photosynthesis over three billion years ago, in blue-green algae (Cyanobacteria), which were the most primitive oxygenic photosynthetic organisms.
Obinger C, Regelsberger C, Strasser C, Burner U, Peschek CA (1997) Purification and characterization of a homodimeric catalase-peroxidase from the cyanobacterium Anacystis nidulans. Biochem Biophys Res Commun  235:545-552
Obinger C, Regelsberger C, Strasser C, Peschek CA (1997) Scavenging of activated oxygen species in cyanobacteria. 9th  International Symposium on Phototrophic Prokaryotes.Vienna, Austria  p.142
Gall EA, Küpper FC, Kloareg B (2004) A survey of iodine content in Laminaria digitata. Botanica Marina  47: 30–37 
*Evolution of carotenoids and other plant-specific antioxidants.
A summary report of evolution of some well-known antioxidants 
Selenium
Selenium is an antioxidant mineral, greatly present in primitive seawaters and is an essential component of the enzyme glutathione peroxidase in mammals. Selenium is present in cellular peroxidases and deiodinases ( type 1 and 3), which are able to extract electrons from iodides, and the latter iodides from iodothyronines. One family of selenium-containing molecules as glutathione peroxidases (GPx) repairs damaged cell membranes, while another (glutathione S-transferases) repairs damaged DNA and prevents mutations ( Stadtman, ’96). Selenium acts synergistically with iodine. The mono-deiodinase ( type I and type III ) enzymes are selenium-dependent and are involved in thyroid hormone regulation. In this way selenium status may affect both thyroid hormone homeostasis and iodine availability. 
Several selenoproteins participate in the protection of thyrocytes from damage by H2O2 produced for thyroid hormone biosynthesis. The deiodinase isoenzymes constitute the second family of eukaryotic selenoproteins with identified enzyme function. Deiodinases catalyze the reductive cleavage of aromatic C-I bonds in ortho-position to either a phenolic or a diphenylether oxygen atom in iodothyronine. Trace elements involved in glutathione peroxidase and superoxide dismutases enzymes activities – i.e. selenium, magnesium, copper and zinc, were lacking in some terrestrial iodine-deficient areas selenocysteine (Gladyshev and Hatfield, ’96). From about three billion years ago, prokaryotic selenoprotein families drive selenocysteine evolution. This micronutrient is incorporated into several prokaryotic selenoprotein families in bacteria, archaea and eukaryotes as selenocysteine (Gladyshev and Hatfield, ’96). The selenoprotein peroxiredoxins protect bacterial and eukaryotic cells against oxidative injury. Also selenoprotein families of GPx and deiodinase of eukaryotic cells seem to have  a bacterial phylogenetic origin. The selenocysteine-containing form also occurred in other fish, chicken, sea urchin, green algae and diatoms. New selenoproteins are recently (about 200 Mya) developed in mammalians (Castellano et al., 2004; Kryukov and Gladyshev, 2004; Wilting et al. ’97; Zhang et al., 2005). Marine fish and vertebrate thyroid gland have the highest concentra¬tion of selenium and iodine.
Ascorbic acid (Vitamin C)
Ascorbic acid (“Vitamin C” for humans) is a common antioxidant in mammals . Ascorbic acid  is a water soluble antioxidant and it exists primarily as ascorbate at physiological pH. Ascorbate is a powerful reducing agent capable of rapidly scavenging a number of ROS. Freshwater teleost fishes also require dietary (vitamin C) in their diet or they will get scurvy (Hardie et al.,’91). The most widely recognized symptom of Vitamin C deficiency in fish is scoliosis, lordosis and dark skin coloration. Terrestrial freshwaters salmonids also show impaired collagen formation, internal/fin haemorrhage, dark colouration, distorted/twisted gill filaments, poor wound repair, increased mortality, reduced egg hatchability. If fishes are housed in seawater with algae and phytoplankton, then vitamin supplementation seems to be less important, presumably because of the availability of other antioxidants in natural marine environment (Hardie et al.,’91).
For this reason, we hypothesise that the antioxidant action of ascorbic acid developed in the cell metabolism when, about 400 Mya, animals (fishes) and  plants started to adapting themselves to mineral (and iodine) deficient fresh waters of estuary of rivers and land. Like plants, most mammals (with exception of humans and guinea pigs) make their ascorbic acid from glucose and can make glucose from ascorbic acid. Remote ancestors of humans suffered a genetic mutation about 40-45 million years ago and haven't been able to make “vitamin C” since. Therefore living humans need nowadays to get all our “vitamin C” from food. Some scientists think that the loss of our ability to make “Vitamin C” may have caused Homo Sapiens' rapid evolution into modern man (Challen et al., ’98; Benhegyi et al., ’97; Stone, ’79).
Carotenoids and Flavonoids 
More than 600 plant carotenoids have been identified in plants but less than 50 are abundant in the human diet. Carotenoids are nutritionally important for normal cell regeneration, plus numerous other health aspects linked to unstable oxygen molecules called free radicals (Packer, ’92; Packer, ’93; Cadenas and Packer, 2002). Lucy and Lichti (1969) reported an interesting electron transfer from vitamin A (and carotenoids) to iodine in cellular membranes, in which iodide ions are formed, where a double bond in retinol (or retinoic acid) is presumably the source of these electrons that are transferred from the vitamin to iodine. Two different mechanisms may be proposed in the present context to account for the effectiveness of very small quantities of vitamin A in vivo.
(1) The electron-deficient products that are formed when the vitamin behaves as a donor have access to a regenerative source of electrons. 
(2) Vitamin A interacts with a donor of electrons immediately before, or at the same time as, it donates electrons itself. The electron-acceptor properties of vitamin A, and its interactions with electron-donor substances, may be relevant to the latter possibility.  
In both of these theoretical mechanisms electron transfer occurs without the vitamin being destroyed. In fact carotenoids and vitamin A (as iodine/iodide) are both excellent donors and acceptors of electrons. Vitamin A participates catalytically in certain oxidation-reduction reactions that are essential for the normal functioning of organized tissues in vivo, and the physical properties of vitamin A indicate that these reactions may occur on or in membranes. Flavonoids and carotenoids are the biggest group of antioxidant phytochemicals studied. 
Some of these pigmented antioxidants form the colors of plants and in particular of fruits and flowers. Flowering plants are Angiosperms, which produce seeds enclosed in fruits and flowers. Angiosperms, the dominant type of plant today, evolved rather recently about 200-100 million years ago from cone-bearing gymnosperms, during the late Jurassic period. So also most of the antioxidant pigments are evolved rather recently. Most of carotenoids are "sacrificial" antioxidants, in other words, carotenoid molecules are not regenerated like other antioxidants, and are degraded in the process of neutralizing free radicals or reactive oxygen species.
*Evolution of animals dependent on plant-produced antioxidant vitamins.
When about 500-300 Mya some living plants and animals began to transfer from the sea to rivers and land, environmental I-deficiency was a challenge to the evolution of terrestrial life (Venturi 2000a). In fishes, plants and animals the terrestrial diet became deficient in many primitive marine trace-elements, including iodine and selenium. 
Terrestrial plants slowly optimized the production of “new” endogenous antioxidants such as ascorbic acid,  polyphenols, carotenoids, flavonoids, tocopherols, some of which became essential “vitamins” in the diet of terrestrial animals (vitamins C, A, E). According to Coic and Coppenet (1990) and Lamand (1991), iodine and selenium became no longer necessary to many plants. 
In a different way, some chordates, about 500 Mya, began to use also the “new” thyroidal follicles, as reservoir for iodine, and to use the thyroxine in order to transport antioxidant iodide and triiodothyronine into the peripherical cells. Triiodothyronine (T3), the biologically active form of thyroid hormone in vertebrates, became active in the metamorphosis and thermogenesis for a better adaptation to terrestrial fresh-waters, atmosphere, gravity, temperature and diet. 
The family of peroxidase enzymes includes mammal, mi¬croorganism, plant, algal, and fungal peroxidases. Some of these peroxidases, known as haloperoxidases, use halide ions (iodide, bromide, and chloride) as natural electron donors, and have an antioxidant function in Cyanobac¬teria (Obinger et al. 1997, 1999; Venturi and Venturi 1999). Taurog (1999) reported that the relation between animal and non-animal peroxidases probably rep¬resents an example of convergent evolution to a common en¬zymatic mechanism. 
Broadhurst et al.(2002) and Cunnane (2005) suggested that early Homo sapiens, living around the Rift Valley lakes and up the Nile Corridor into the Middle East, received iodine and n-3 fatty acids from littoral food resources.
Dobson (1998) suggested that Neanderthal man suffered I-deficiency disorders caused by inland environment or by a genetic difference of his thyroid compared to the thyroid of the modern Homo Sapiens. I-deficient humans, like endemic cretins, suffer physical, neurological, mental, immune and reproductive diseases. Iodine has favored the evolution of the nervous system for a better adaptation to terrestrial environment as recently reported by 
Cunnane (2005), who suggested that “iodine is the primary brain selective nutrient in human brain evolution.” Cordain et al.(2005) recently reported that the significant changes in diet, that began with the introduction of agriculture and animal husbandry approximately 10,000 years ago, occurred too recently on an evolutionary time scale for the human genome to adjust. In conjunction with this discordance between our ancient, genetically determined biology of hunter-gatherers and fisher-gatherers human societies and the nutritional patterns of contemporary Western populations, many of the so-called diseases of civilization have emerged. 
Cordain suggests that iodine deficiency was probably one, among other dietary variations, introduced during the Neolithic and Industrial Periods, which have altered crucial nutritional characteristics of ancestral human diet (simultaneously fiber and polyunsaturated fatty acid contents). The evolutionary collision of our ancient genome with the nutritional qualities of recently introduced foods may underlie many of the chronic diseases of Western civilization. 
I think that studies of molecular evolution of primitive antioxidants might provide the basis for further research into “new” active substances against many human chronic pathologies. 
Regards,  Sebastiano
Comments? TimVickers 15:57, 16 April 2007 (UTC)
replies: text: Melatonin evidently started out as an antioxidant before it acquired a signaling role.  See the relevant page.--68.35.43.82 13:32, 25 April 2007 (UTC)

text: One of the better (best?) examples of antioxidant evolution might be the sequestration of iron (sometimes with directed H2O2 scavenging) into protein cages, aka ferritin, bacterioferritin, Dps, DpsL, etc.  Check  and  for background. TheTweaker 14:55, 22 June 2007 (UTC)
replies: text: Indeed. That's already covered in the third paragraph of the "Overview" section. TimVickers 15:24, 22 June 2007 (UTC)
replies: text: It's mentioned there, but it's lacking the fact that some ferritins can act as a dismutase.  However, my point is that the ferritins should be included in any discussion of antioxidant evolution: the structural and sequence conservation, ubiquity throughout kingdoms, varying catalytic activity etc all make them a good example of the evolution of oxidative stress mechanisms.  Persons better familiar with them than I might make the case for them to be one of the oldest and most important antioxidants.  TheTweaker 16:43, 22 June 2007 (UTC)
thread_title: Evolution outline

message: Selenium is not really an antioxidant. Selenium is a toxic metal. Selenocysteine is an amino acid present in several selenoproteins that have antioxidant functions, but this does not make selenium an antioxidant as other elements are equally important for the function of these enzymes. Selenium is certainly essential for the function of some antioxidants, but I don't really think this makes the element an antioxidant itself. TimVickers 18:31, 16 April 2007 (UTC)
thread_title: Selenium as an antioxidant

message: Hi, I was gonna add :Image:Foods highest in antioxidants.jpg to this page 'cause it looks informative (pinto beans? I had no idea..), but since this is an FA under mediation.... I'll just let y'all decide. later... Ling.Nut 05:24, 12 June 2007 (UTC)
replies: text: Tabular data shouldn't really be presented in an image file (see WP:MOS), but this data might be quite a useful addition to List of antioxidants in food if it were converted to the correct format. TimVickers 14:52, 12 June 2007 (UTC)
replies: text: I was just trying to find a home for the orphan... if it needs to be converted to a table, I'll leave that task for someone else.. thanks.. Ling.Nut 15:07, 12 June 2007 (UTC)
replies: text: I'll happily convert it to a wikitable. However, it would be nice to find a "citable" source we can attribute the information to (i.e. an URL, not just "USDA"). Also, is there an unit for "Total antioxidant capacity per serving size"? Fvasconcellos (t·c) 19:38, 12 June 2007 (UTC)
replies: text: Done, in my sandbox. I'd still like a source and an unit :) Fvasconcellos (t·c) 19:51, 12 June 2007 (UTC)

text: Added to your sandbox. TimVickers 20:13, 12 June 2007 (UTC)
replies: text: Excellent! Feel free to move it to its proper location, then. I agree it would be a welcome addition to our List of antioxidants in food. Perhaps on Oxygen radical absorbance capacity as well? Fvasconcellos (t·c) 20:20, 12 June 2007 (UTC)

text: Done and done. TimVickers 20:33, 12 June 2007 (UTC)
thread_title:  orphan image: [[:Image:Foods highest in antioxidants.jpg]] 

message: "Redox cycling may allow other antioxidants (such as vitamin C) to act as pro-oxidants, counterintuitively promoting free radical formation."
Vitamin C first acts as an anti-oxidant before acting as a pro-oxidant.
I suggest that ", counterintuitively promoting free radical formation" be deleted.
Michael H 34 01:08, 22 June 2007 (UTC)
replies: text: Pro-oxidants do promote free-radical and ROS production though, what about "...to act as pro-oxidants and promote free radical formation." TimVickers 02:02, 22 June 2007 (UTC)

text: It is the reduced form of antioxidants that produce ROS, usually through reduction of metal ions. This is explained in a bit more detail on the pro-oxidant page. TimVickers 22:34, 22 June 2007 (UTC)
thread_title:  Redox recycling 

message: Vitamins that are reducing agents can also be pro-oxidants.  Vitamin C has antioxidant activity when it reduces oxidizing substances such as hydrogen peroxide, however, it can also reduce metal ions which leads to the generation of free radicals through the fenton reaction.
:2 Fe3+  +  Ascorbate  →  2 Fe2+  +  Dehydroascorbate
::2 Fe2+ + 2 H2O2 → 2 Fe3+ + 2 OH· + 2 OH−
The relative importance of the antioxidant and pro-oxidant activities of antioxidant vitamins are an area of current research, but vitamin C, for example, appears to have a mostly antioxidant action in the body. However, less data is available for other dietary antioxidants, such as polyphenol antioxidants, zinc, and vitamin E.
(I only changed the order of the reactions.)
Best wishes,  Michael H 34 23:36, 22 June 2007 (UTC)
thread_title: Anti-oxidant vitamins can also be pro-oxidants

message: The third sentence mentions a 
"dangerous chain reaction"  
that can be caused by free radicals.  The use of dangerous here needs some context for this article and introduction to stand on its own.  I don't know what type of danger these radicals may be putting us in, otherwise I would edit it myself.  Thanks.
::Rewritten to give specific example. TimVickers 02:45, 22 June 2007 (UTC)
thread_title:  Dangerous Chain Reaction 

message: The scheme "The free radical mechanism of lipid peroxidation." is incorrect.  It is the allylic positions that are attacked, not the vinyl C-H.--Smokefoot 23:17, 30 July 2007 (UTC)
replies: text: Thanks, you're quite right. Is there anything else wrong with the new version? Tim Vickers 23:31, 30 July 2007 (UTC)
replies: text: The SVG is now fixed. Fvasconcellos (t·c) 00:10, 31 July 2007 (UTC)

text: The regiochemistry of the allylic oxygenation looks ok - you folks work fast.  From March's "Advanced Organic Chem" the homolytic bond dissociation energy for allylic CH (i.e., CH2CHCH2-H) is 361 kJ/mol, vs. 419 for ethane (Et-H) vs 444 for ethene (CH2CH-H).  In terms of the presentation, O2 appears at first glance to be a product whereas one might place this reagent over an arrow.  Also the same unsaturated lipid is shown twice, which is confusing to me at least.  And usually, ROO. is thought to abstract an (allylic) H from another lipid to give hydroperoxide (ROOH) and a new allyl radical, hence the key idea of a radical chain.  Finally, while I am at it, the identity of the radical initiator is usually not known, is there really a proposa that its HO.? (O2 is out, I know)  This report is indeed very nice and should be well received. --Smokefoot 22:58, 31 July 2007 (UTC)
replies: text: Looks good to me.  --Smokefoot 00:42, 1 August 2007 (UTC)
replies: text: And fixed. Sorry, Tim—I know you want to have a go at Inkscape :D Fvasconcellos (t·c) 02:42, 1 August 2007 (UTC)
thread_title: The mechanism shown is incorrect

message: Under Health Effects - adverse effects:
"smokers given beta-carotene supplements", "smokers given beta carotene", and "showed that β-carotene, vitamin A".
Which one of these is right (or at least more appropriate)? Fabometric (talk) 14:26, 13 December 2007 (UTC)
replies: text: Good point, "smokers given supplements containing beta-carotene and vitamin A had increased rates of lung cancer" is more accurate. Thank you. Tim Vickers (talk) 16:02, 13 December 2007 (UTC)
thread_title: B-carotene question

message: This page is confusing for the average reader. Side by side claims such as "the SU.VI.MAX trial, which suggested that antioxidants have no effect on cause-all mortality", "Antioxidants can cancel out the cell-damaging effects of free radicals,[8] and people who eat fruits and vegetables rich in polyphenols and anthocyanins have a lower risk of cancer, heart disease and some neurological diseases.[119]" and "however antioxidant vitamin supplementation has no detectable effect on the aging process, so the effects of fruit and vegetables may be unrelated to their antioxidant contents.[109][110]" end up meaning nothing for the average reader. People shouldn't have to do a year long literature review and be PhDs in biochemistry to make sense of this article. Can an expert please address the questions everyone has in mind when reading this! Should one take antioxidant supplements? How much? For what? Should one eat foods rich in antioxidants instead? Or is there too much contradicting data to tell? This should be clearly spelled out. I'm a physiology major and the section on health effects confused the hell out of me! How can I possibly evaluate the relevancy of all those studies? What about the average joe who just wants to pick up good eating habits? What is he supposed to think? Come on, we can do better than this! I'm not an expert but I'm sure there are some out there who would have a word to say about this. As it is, it's merely a list of studies that are overall confusing. We need a clear summary and conclusion. Can someone please do some editing and summarizing of this section? We need the average reader to leave this page feeling that s/he understood what the scientific community knows about the health effects antioxidants and what there is doubt and controversy about. Thank you! Horia (talk) 21:24, 14 February 2008 (UTC)
replies: text: I thought the section in the lead might achieve that "Antioxidants are also widely used as ingredients in dietary supplements in the hope of maintaining health and preventing diseases such as cancer and coronary heart disease. Although some studies have suggested antioxidant supplements have health benefits, other large clinical trials did not detect any benefit for the formulations tested, and excess supplementation may occasionally be harmful." Is this still too confusing and technical? I've also re-written first section of the "disease prevention" section, to try to make this clearer. Tim Vickers (talk) 21:31, 14 February 2008 (UTC)
replies: text: Seems like a clear summary of current knowledge; 'eat your fruits and veggies and don't waste time with supplements'.CynRNCynRN  Talk 18:52, 1 May 2008 (UTC)
thread_title: What's in it for the average reader?

message: The following statement is inaccurate:
"people who eat fruits and vegetables, which are good sources of antioxidants, have a lower risk of cancer, heart disease and some neurological diseases.[119]"
It should read:
"people who eat fruits and vegetables, which are good sources of antioxidants, have a lower risk of heart disease and some neurological diseases,[119] and there is evidence that some types of vegetables, and fruits in general, probably protect against a number of cancers." (reference: http://www.dietandcancerreport.org/downloads/chapters/chapter_04.pdf - 4.2.7 Conclusions)
--Phenylalanine (talk) 23:45, 16 March 2008 (UTC)
replies: text: That new version goes from talking about antioxidants to referring to "these foods" without saying what "these foods" actually are. Tim Vickers (talk) 18:17, 8 January 2010 (UTC)
thread_title: Cancer prevention

message: This is a fine overview, and it overall probably deserves its status as a featured star class article.  However, there are a couple of suggestions and concerns.  First of all, the relationship between antioxidant activity and effects on numerous other cellular pathways is still a bit murky and poorly articulated, both within state-of-the-art science and within the article.  The article leaves the reader with the impression that antioxidant compounds have a neatly discreet mechanism of cellular action, when there is plenty of evidence that this is simply not true, and indeed could not be true.  
For example, it is clear that numerous classical polyphenol antioxidants have a host of other effects on cellular mechanisms beyond reduction of reactive oxygen species, including what appears to be a common down-regulation of nuclear factor kappa B (a transcription factor widely regarded as a fundamental link between chronic inflammation and the eventual generation of cancer).  It may turn out that numerous phytochemicals protect us from cancer not primarily because of reduction of reactive oxygen species and associated damage to DNA but also because of their inhibitory effects on NF kappa B, and their associated promotion of apoptosis in damaged cells.  Additionally, the classic polyphenol antioxidant resveratrol (one of the hottest molecules in the anti-aging business) may have its most biologically protective effects mediated through mechanisms that have little or nothing to do with the reduction of oxidative stress.  For example, resveratrol appears to activate surtuins, and about 20 other cellular pathways (including COX-2, iNOS, JNK, MEK, AP-1, p53, Bax, caspases, survivin, cyclins, Bcl-2, CIAP, Egr-1, PKC, PKD, casein kinase II, 5-LOX, VEGF, IL-1, IL-6, IL-8, just to name a partial list). (see Aggarwal 2006 in Biochemical Pharmacology for an excellent review).  
Indeed after reading some of the recent molecular work on antioxidant phytochemicals, one has to genuinely wonder if the term antioxidant really does them justice.  It seems like they are more very complex cellular physiology modulators affecting transcription pathways, energy metabolism pathways, inflammatory pathways, apoptotic mechanisms, and a dizzying array of cellular signaling processes.  However the term "cell physiology modulators" obviously is not going to catch on or replace the term "antioxidants".  However, if this is truly a star class article in Wikipedia, it should reflect some of these considerations.  DFW April 8, 2008
:Hi there, thanks for the comments. The problem is that this article is about "antioxidants" and the antioxidant activities of various enzymes and compounds, the fact that some compounds may have other activities in addition to their antioxidant effects is something that should be discussed in the articles on these particular compounds but wouldn't really fit in the article about their antioxidant effects. For example, I could write a lot about the role of glutathione in xenobiotic metabolism, but this wouldn't belong in this article. However, you are right that I should probably note that the polyphenolics in particular have other effects in the section on clinical trials, since this may be one reason why the level of antioxidant intake don't seem to correlate with any health benefits. Tim Vickers (talk) 00:16, 9 April 2008 (UTC)
thread_title:  Some General Concerns and Questions - A Possible Clarification

message: This sentence...
"However, no benefits to athletes are seen with vitamin A or E supplementation."
...is contradicted by the footnote it is attached to.  The study cited (http://www.ncbi.nlm.nih.gov/pubmed/10701711) reports: "Supplementation with 100 to 200mg of vitamin E daily can be recommended for all endurance athletes to prevent exercise-induced oxidative damage and to reap the full health benefits of exercise."
Also, there is no mention of Vitamin A in the study that was cited.
Thanks...Kevin  —Preceding unsigned comment added by 63.203.211.242 (talk) 23:21, 25 June 2008 (UTC)
replies: text: That reference says "The majority of subsequent well controlled studies have reported no significant effect on physical performance from vitamin E supplementation." so I have reworded this sentence to say "However, no benefits for physical performance to athletes are seen with vitamin E supplementation." Tim Vickers (talk) 02:06, 26 June 2008 (UTC)
thread_title: Misleading Sentence