OmniAct Mango – A fortified Mango (Mangifera indica) extract with high anti-oxidant potential
Ajinomoto NaturalSpecialities
Dr Hollman, associate professor at RIKILT – the Institute of Food Safety at Wageningen University, said decades of research had turned up little that demonstrated polyphenols’ ability to deliver antioxidant benefits in vivo.
The compounds had other more complicated potentialities for human beings, he said, which was where his research efforts, and those of other scientists were moving.
“What we have found is that polyphenols don’t add too much [to the body’s defence against oxidative damage],” he said at the NutraIngredients Antioxidants 2010 conference in Brussels recently.
“If you are really depleted with all kinds of antioxidants and your system is not functioning well then maybe there is some possibilities that antioxidants can have an additional effect but for a healthy population there is no effect at all.”
“But there is a lot of evidence that polyphenols have good effects in your body; they have good effects on the cardiovascular system and there is some good evidence for that but that has nothing to do with their antioxidant activity. So they are healthy compounds to some extent but not because they are antioxidants but because they have lots of other properties. That’s the interesting part. There are a lot of other properties which are really very interesting.”
7 comments (Comments are now closed)
Listen to what is said, not to what you want to hear
Thank you very much Peter, for saying out loud and clear what is well known, but often not said! To achieve progress in this field (and others) and exploit its many possibilities, it is necessary to face the facts and use the data as they are, not as we want them to be!
It is incredibly easy to overlook the unexpected, see http://viscog.beckman.illinois.edu/grafs/demos/15.html for an illustrative example.
Another good example, which specifically addresses several antioxidant vitamins, is the paper by Tatsioni et al. 2007, JAMA 298: 2517-2526.
The fact that things don't work in the way we expected, does not mean that there is no effect, it just means that the effects must be investigated in other ways than before. Unfortunately it also means that much of the previous research, designed and done according to the old mindset, is no longer relevant.
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Posted by Dr Kirsten Brandt
05 August 2010 | 11h05
Polyphenols do have a role
I go with the comments made by earlier commentators.There are whole lot of studies from Japan and China which show effect of green tea.They may not add anything extra ,if your antioxidant system is intact, but what about in conditions like obesity, cancer and even in aging, as Hollman himself has admitted..
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Posted by Giridharan Nappanveettil
24 July 2010 | 02h32
On the other hand....
I think Dr. Hollman has adopted an extreme point of view. Certainly the polyphenolic literature tells us that these plant-derived ring compounds are not only potent antioxidants, but also have the capability of modifying enzyme activity and signaling pathways as well as interacting with chromosomes and altering the expression of important genes critical for human health.
We have shown that an isotonic polyphenolic product, Isotonix OPC-3, can modify various parameters in the cardiovascular system and reduce circulating concentrations of C-reactive protein by greater than 50% (M.R. Cesarone et al., Improvement in circulation and in cardiovascular risk factors with a proprietary isotonic bioflavonoid formula OPC-3. Angiology 59 (4): 408-414, Aug.- Sept. 2008). We also observed a concomitant drop in oxidative stress as measured by the D-ROM test, indicating that antioxidant compounds were diffusing into circulation.
As a follow-up D-ROM study, we conducted a time course study comparing OPC-3 prepared as an isotonic liquid versus tablets of OPC-3 powdered extracts (M.R. Cesarone et al., Accelerated antioxidant bioavailability of OPC-3 bioflavonoids administered as isotonic solution. Phytotherapy Research, published online in Wiley Interscience, DOI: 10.1002/ptr.2651, 2009.) Although both delivery forms of polyphenolic compounds resulted in significant, time-dependent reduction in oxidative stress markers, the isotonic delivery system was superior. Clearly, both studies showed that regardless of whether the isotonic OPC-3 solution was ingested for 8 weeks (Angiology) or for one sitting (Phytotherapy Research), the polyphenolic compounds are absorbed within 10 minutes (as measured by lowered reactive substances in a small blood sample by the D-ROM test) and have significant, sustained antioxidant activity up to 4 hours after ingestion on an empty stomach.
While the human body has numerous antioxidant systems to neutralize radicals, there appear to be additional radicals that can be scavenged by the use of antioxidant products.
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Posted by James L. Wilmer, Ph. D.
20 July 2010 | 17h52
Yes, he is right!
I fully agree with Dr. Hollman. We have also reported a number of times that many 'powerful' antioxidants are either metabolized or not absorbed and do not exert antioxidant activity in vivo as the ingested parent polyphenols do in vitro.
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Posted by Dr. Juan Carlos Espin
14 July 2010 | 17h09
Let me see if I understand
If polyphenols are the most potent and plentiful dietary antioxidants (well established) but have little or no value as antioxidants, it would seem to follow that antioxidants in food have little or no value, unless somehow, fewer amounts of weaker antioxidants (C, D, E, selenium) have greater value. Are we seriously ready to make that leap?
Is it coincidence that the polyphenols with the highest antioxidant capacity (resveratrol, ECGC, procyanidins) are also the most beneficial, or that foods with the highest antioxidant value are also whole foods, the least processed foods, the healthiest foods?
The Mayo Clinic is not testing just any green tea polyphenol in leukemia patients. They're testing high doses of pure EGCG, the highest antioxidant compound in tea.
Tufts University has reported that polyphenol-rich blueberry juice reverses dementia symptoms in Alzheimer's patients. Blueberry juice has a high antioxidant capacity. We do not see these same results with watermelon or other fruits with less concentrated polyphenol profiles (and lower antioxidant capacity). If antioxidant capacity were only valuable as a mechanism to determine polyphenol-rich foods potent enough to affect AD symptoms, it would still be a useful measure. But that is clearly not the only value of antioxidant capacity, as an overwhelming body of science shows.
I understand that Dr. Hoffman wants to look beyond the antioxidant factor, but dismissing dietary antioxidant capacity as irrelevant doesn't fit the facts.
There are serious economic and political incentives behind EFSA and FDA censorship of health claims. I have little trust that the public health is the true priority. Public health policy in the USA, based on the interests of the food and drug industries, is now yeilding catastrophic consequences. Epidemics in AD, obesity, diabetes and cardiovascular disease are not the result of eating too many antioxidants. In fact, there is good evidence that the opposite is true.
The message the public will get is that antioxidants don't work and make no difference. This is not only demonstrably wrong, it will serve to compound the public health disasters now looming.
Perhaps we should remove the high antioxidant foods from the American diet and see what happens? Oh wait- we already have, and it's a disaster. Could there be some other reason to warn people away from high-antioxidant foods? If "useless" doesn't work, we could try "dangerous." I have no doubt we will.
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Posted by David L. Kern
14 July 2010 | 00h44
Question of absorption in the first place
I would like to talk to Dr. Hollman. I am researching encapsulating nutraceuticals in nanoparticles. I have heard from another researcher with thirty years nutracetical/cancer research, and he says a large portion of the phytochemicals in the clinical literature weren't absorbed into the systemic circulation from their peroral protocols.
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Posted by Charles Armes
12 July 2010 | 22h14
I agree with peter Hollman
Most researchers have known for some time that in-vitro antioxidants are not effective in-vivo. An antioxidant health claim has little meaning and EFSA have backed this science-based conclusion.
Polyphenols do have active molecules which interact with signalling pathways and improve blood flow.
Long-live polyphenols - antioxidants are dead!
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Posted by Richard
12 July 2010 | 14h23
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