Talk:Health effects of phenols and polyphenols

May polyphenols cause cancer? There is no data to support this!
The data you have http://www.nejm.org/doi/full/10.1056/NEJM199309233291302 is irrelevant and does not refer to cancer induced by polyphenols. The assumption about that is made by yourself! Please give reliable data that support the above assumption, otherwised remove it because it is wrong. I haven't noticed any scientific reference about cancer caused by polyphenols in the pub med or cochrane library. 688dim (talk) 12:22, 16 March 2011 (UTC)

Potential references
Moved from Further reading section: --Ronz (talk) 03:08, 29 December 2011 (UTC)
 * D’Archivo, M. et al. ”Polyphenols, dietary sources and bioavailability”, Annali dell'Istituto Superiore di Sanità (2007),43(4):348-361.
 * Hu, Miao-Lin “Dietary polyphenols as antioxidants and anticancer agents: more questions than answers”, Chang Gung Medical Journal (2011),34(5):449-460.
 * Queen, B.L. / Tollefsbol, T.O. “Polyphenols and Aging”, Current Aging Science (2010),3(1):34-42.
 * Quideau, S. et al. ”Plant Polyphenols: Chemical Properties, Biological Activities, and Synthesis”, Angewandte Chemie International Edition (2011),50(3):586-621.

Thank you for your opinion and suggestion.

These reviews are meant for readers who would like to delve deeper into the subject.

The reviews are placed in the “further reading” – section because the Wikipedia guideline for this section read: “… publications that would help interested readers learn more about the article subject. The Further reading section (…) should normally not duplicate the content of the References section” (WP:FURTHER).

The Wikipedia content guideline for “Identifying reliable sources (medicine)” (WP:MEDRS) read: “It is usually best to use reviews and meta-analyses where possible.”

The reviews in question reflect the latest research (last 10 years) in the field, they are scholarly and peer-reviewed, and they are published in academic journals. Granateple (talk) 13:34, 29 December 2011 (UTC)

Revisions
Had to make some revisions based on my revisions of the general topic 'polyphenols'. Before the edits, it looked like biting into an apple could cause cancer....(talk) 22:34, 12 August 2013 (UTC))

Research added
I added some proper research about the health affects of polyphenols. I included a reference to this research. Sadly the additions were deleted by https://en.wikipedia.org/wiki/User:Alexbrn. I would be happy to discuss here. Saul "benqish" Davis 19:49, 16 November 2013 (UTC)
 * I was deleting your addition at the same time but User:Alexbrn beat me to it.  Please read WP:MEDRS and reconsider your edit.. the content you wrote was far too strong and certain for a single clinical study. Jytdog (talk) 19:54, 16 November 2013 (UTC)
 * It is very bad form to do anything to another editor's comments without their explicit permission.  You should not have moved my comments to Talk:Polyphenol without without asking.Jytdog (talk) 20:28, 16 November 2013 (UTC)
 * My apologies but you will agree that Talk:Polyphenol is the correct place! Saul "benqish" Davis 05:01, 17 November 2013 (UTC)
 * No buts about it. I do not agree; had you asked I would have said no. The discussion goes where the relevant edits are. Jytdog (talk) 05:58, 17 November 2013 (UTC)

Dose is a crucial thing
it doesn't seems right to incubate cells with a substance to prove if it is carcinogenic ! ! "potentially" too many compounds that are healthy may have devastating effect if applied in high concentration ... I guess even if you use a high concentration of amino acids cells may show bad outcome. no sufficient discussion about what dose did that study use, but in general a study should respect the bioavailability & the "expected" range of plasma concentration. — Preceding unsigned comment added by Yasir muhammed ali (talk • contribs) 04:33, 21 March 2018 (UTC)

Removal of more recent literature reviews on health effects
Pertaining to:. Seriously Zefr, a single old 2013 review is used to say that there is negative results. You should certainly know that "absence of proof is not the proof of absence". If such a single source is deemed adequate, certainly multiple reviews converging on "there may be beneficial effects", which is their words and is a lot more evidence than a negative result, is adequate. --Signimu (talk) 13:49, 7 October 2019 (UTC)

Plus in fact the reviews do not say there may be beneficial effects, they find significant effects, but I added "may" since it's not the role of researchers to make recommendations but health institutions, you know that very well Talk:Intermittent_fasting. If I don't add "may", you revert because it's not toned down enough, and when we add "may", you say it's unencyclopedic because not certain enough. There is NO guideline that requires content to be sure to be added to Wikipedia, it only needs to be verifiable from high quality reliable sources, which these references are. Your interpretation of WP guidelines is inconsistent. --Signimu (talk) 14:00, 7 October 2019 (UTC)
 * Nice sense of humor ;-) From the 2013 review currently used in the entry (BTW not even a systematic one, and also including animals), here's what it says: «As such, there is good evidence to suggest that the acute and/or regular consumption of flavan-3-ol rich cocoa or tea can have a positive effect on the vascular system, mainly through their effects on endothelial function, NO bioavailability, and BP. However, the long-term effects of flavan-3-ol interventions are presently unclear, and there are issues to resolve with respect to the efficacy of tea and caffeine.» --> contrast with what is currently written: «A review published in 2013 found insufficient consensus for the hypothesis that the specific intake of food and drink containing flavonoids may play a meaningful role in reducing the risk of cardiovascular diseases.». You see the difference? What is written currently fails verification. Furthermore, the systematic reviews on humans I have provided, and which are more recent, support the same conclusion. Furthermore, the EFSA now recognizes the flavonols beneficial effects in cocoa, as I added and you rewrote with more details (thank you). Can we agree to rewrite this part to be more faithful to the source, and add the new sources that just say the same? (including that more clinical trials are needed). --Signimu (talk) 14:23, 8 October 2019 (UTC)
 * Same for the ref currently used for this sentence in the entry: «Preliminary research on the association of consuming polyphenol foods, such as olive oil, soy, and pomegranate products, with lower risk of cardiovascular diseases has been low in quality, with little evidence of any possible benefit.» --> contrast with what the ref writes: «Subgroup analyses and individual studies reported additional improvements in inflammatory markers and blood pressure. Most studies were rated as having low-to-moderate risk of bias. High polyphenol oils confer some CVD-risk reduction benefits; however, further studies with longer duration and in non-Mediterranean populations are required.» -- again this fails verification. Also the "low in quality" fails verification, the ref writes "low-to-moderate risk of bias", which is the opposite! BTW, this systematic review that you keep removing includes 10 cohorts with a total of 125K participants, so that's totally in the continuation of what these previous studies asked to investigate. --Signimu (talk) 14:49, 8 October 2019 (UTC)
 * You know, tbh, I'm not convinced about the claims on polyphenols either, I saw them a lot about the mediteranean diet when researching for NAFLD and IF. Anyway, it's not about our opinion, but what the sources says. I'm ok with not adding these sources, but we can't then others of lesser quality for health claims, let's stay coherent. About cohort studies, I think I understood your point, I won't restore until I get another opinion. Thanks, have a nice day :-) --Signimu (talk) 17:22, 8 October 2019 (UTC)
 * pertaining to reference . If it is going to be used to say that polyphenols act as anti-oxidants in vitro but in vivo effects are negligible, should it also be mentioned that they may have indirect effects as antioxidants being metal chelators?Marissaviqueira (talk) 00:37, 9 November 2019 (UTC)Marissaviqueira

Lab research on "anti-inflammatory" effects
made this edit for this article about polyphenols and human health, and on the Polyphenol article here, both of which I reverted. Both edits are based on lab research on mice or in vitro, which is basic primary research at the lowest level of evidence quality, so is not usable to address inflammation mechanisms or effects in vivo, or more broadly human health, as described in WP:MEDANIMAL and WP:MEDASSESS. The last paragraph in this section addresses why. Please don't edit war and discuss further here. --Zefr (talk) 04:58, 13 December 2019 (UTC)

Proposed deletion
The proposed deletion is premature and far ahead of the guidelines. There has been no discussion and no attempt to improve the article with adequate WP:MEDRS reviews. See WP:MOVE where steps to preserve content and sources and those involving a merge of material are considered. Zefr (talk) 23:56, 14 May 2022 (UTC)


 * The article is WP:REDUNDANTFORK. Polyphenols is very similar. Ggux (talk) 08:25, 15 May 2022 (UTC)


 * Some effort needs to be taken to define the scope of this article because it's too broad. We have pages on over 600 phenols. Vitamin E is a phenol (essential, good), 2,4-dinitrophenol is a phenol (toxic, bad). Naturally occurring phenols is another possible merge location. --Project Osprey (talk) 10:07, 16 June 2022 (UTC)

Bioactives
Some polyphenols are bioactives - there is abundant literature from the last decade, e.g. Lupton et al. []. The paper by Yetley cited in the text [] is a report from a US/Canada workshop which highlights discussions that take place - I'm not sure why @Zefr considers this source as "dubious". The Linus Pauling Institute is considerably less reliable as it is neither peer-reviewer nor from a disinterested source.

The entire entry is fairly light on information anyway - one could expand it a bit, but most of it is fairly speculative when one assumes that even health benefits of flavanols are not permitted to be included in any reasonable way.Ggux (talk) 06:04, 26 August 2022 (UTC)


 * "Bioactive" is a buzzword for compounds that have effects in vitro when applied in supraphysiological doses, but no known effects in vivo because they are impossible to study precisely.
 * User Ggux continues to edit the article with promotional language to push a positive viewpoint on health that remains in question as a professional conflict of interest, WP:COI, posted on the user's talk page. Ggux can declare the extent of that COI here.
 * The article was revised for neutrality with this edit.
 * Each EFSA scientific opinion expressly states in its Disclaimer: "The present  opinion  does  not  constitute,  and  cannot  be  construed  as,  an  authorisation  for  the marketing of...".  EFSA reviews are reports on safety and possible mechanisms, not authorizations, which are a subsequent process handled through the European Commission. No sources have been provided to indicate the cocoa flavanol or olive polyphenol claims are actually approved, active in 2022, and marketed as health claims. Zefr (talk) 22:47, 26 August 2022 (UTC)
 * "Bioactive" is a common expression in nutrition research which has even a definition by the US government (see Bioactive entry). It might be used as a marketing term, but that does not invalidate its use. There is also abundant literature about the use of "bioactives" in dietary guidelines as the expression describes nutrients that are not essential (dietary fibre for example).
 * EFSA opinions are used by the EU commission to authorise health claims - the health claim register can be searched (link added). These health claims exist.
 * A 2mmHg change in systolic blood pressure has a considerable impact on population health - so while it might be minor in effect size, it is quite substantial in effect. It is comparable to Mediterranean Diet or moderate salt reduction.
 * My COI is available - the COI of Zefr is not. Neither is the COI of the LPI which is known to promote certain compounds (in particular Vitamin C). unsigned edit by 05:56, 27 August 2022 (UTC)
 * I agree with the deletion of this article and move of the content and sources, as exist as of today at Polyphenol. WP:PROD indicates a 7-day waiting period after which an admin will delete the article, unless objections are raised. I have no affiliation with LPI or any company or university involved in polyphenol research, whereas the POV-pushing by user Ggux on this article, persistent citing of the COSMOS study, and flavan-3-ol make COI seem likely. Please disclose your professional involvement and adhere to the normal expected practice for Wikipedia editors with COI to avoid editing articles within their professional collaborations, research activities, and publications. Zefr (talk) 19:08, 27 August 2022 (UTC)
 * @Zefr - I have put my COI in my talk page and I would appreciate to see yours as well. I object to POV claims - what I have written is largely consensus in nutrition research. LPI clearly has a POV as evident by many conference presentations by LPI academics. Ggux (talk) 19:35, 27 August 2022 (UTC)
 * There is a disclosure process at WP:DISCLOSE which you have not followed on your talk page under the COI section, and minor information, albeit with your admission of being "terribly biased" from your own research program on polyphenols, is on your user page. Specifically from the COI guide, "you are required by the Wikimedia Foundation's terms of use to disclose your employer, client, and affiliation with respect to any contribution which forms all or part of work for which you receive, or expect to receive, compensation." You attempted to create an article about the Department of Food and Nutritional Sciences, University of Reading, which publishes a bioactives guideline, indicating professional association you may have with this department and university where you are employed and compensated - this violates the COI policy. If you don't clear this up, I will report you to admin.
 * Wikipedia has hundreds of related articles you could be working on other than those related to polyphenols or bioactives where your "terribly biased" views would not raise questions about biased editing for unproven health effects - which you admit, rather than neutral editing, as I have emphasized. Zefr (talk) 20:44, 27 August 2022 (UTC)
 * I am not sure what "unproven health effects" you are referring to. Perhaps you might elaborate. You might also point out which 'bioactive guideline' has been published by the Department of Food and Nutritional Sciences, University of Reading - colleagues from there are unaware of such a guideline being published (in the UK, such a guideline would be published by SACN, OHID or DHSC).
 * Most of all, I would appreciate a discussion that focuses on content and not persons - you make wide ranging (negative) claims that are no longer true. You were - at your own admission - surprised that one can determine the metabolic fate of polyphenols and that they are used as nutritional biomarkers; this is state of the art for at least a decade. You claimed that there was no authorised health claim for polyphenols in the EU when there clearly was. Perhaps it would be good to discuss before making accusations?
 * I am biased - every one is biased, and a good scientist is aware of that. You are equally biased - so perhaps instead of throwing around accusations it would be better to work together? (Although should one really trust someone who threatens doxxing?) Ggux (talk) 08:59, 28 August 2022 (UTC)
 * Over months, the EFSA scientific opinions were used as sources in this article and others, explicitly stating each was not an approval for a health claim, but rather provided evidence of safety and possible causality. The European Commission health claims you eventually included were your original burden to source, WP:BURDEN. But even these are just two rare cases, apparently with no acceptance by other national regulatory agencies of polyphenol health or nutritional effects.
 * The standards for proving health effects and gaining regulatory approval of health claims are micronutrients (RDIs) and prescription drugs. In both cases, anti-disease effects are proved by the compound having in vivo efficacy (dose-response proof) and specificity on a target (mechanism of action, affirmed for drugs by a pharmacological antagonist).
 * Due to their general absence of having met the above standards, it seems unlikely that many polyphenols (or other non-nutrient "bioactives") will have sufficient scientific basis to earn the status of a health-effect RDI or an approved health claim within the foreseeable future. Zefr (talk) 21:54, 30 August 2022 (UTC)
 * EFSA scientific opinions are usually a good overview of the state of science and are generally recognised as being thorough. The EU Commission usually follows EFSA advice - but I appreciate that this is too lax an approach for here and it is good that this has been corrected. However, I do not understand why two health claims are "rare cases" - they are for compounds that have been investigated quite thoroughly - most polyphenols have not. Moreover, a health claim is only assessed if there is a submission by an interested party, i.e. there has to be someone (usually a company) that considers the effort of obtaining a health claim of sufficiently beneficial to them. An absence of a health claim does not provide any information about the health effects or absence thereof of a compound.
 * Unfortunately, this is not correct - see for example fibre (Lutpon, From basic science to dietary guidance: Dietary fiber as an example (2012)). Mode of action is not necessarily important as it is unknown for many compounds (including some prescription drugs). Most dietary recommendations are based on deficiencies, not the prevention of diseases (e.g. Yetley, 2017) and there is an ongoing shift especially in the US dietary guidelines committee about how to address this (Yetley, 2017). Criteria for the development of recommendations are actively discussed (see e.g. Lupton et al., Exploring the benefits and challenges of establishing a DRI-like process for bioactives (2014) and will rather follow Bradford Hill considerations. There is a wealth on literature about this which I have attempted to cite elsewhere. This [] might be useful.
 * There are two aspects to this: health claims are only authorised if there has been an application (see above) - the absence of health claims therefore does not provide any evidence for a lack of activity. Rejected health claims would be more informative. Dietary recommendations are considerably more likely and are actively discussed (see elsewhere) - it is very likely that there will be dietary recommendations in the next decade. The evidence for beneficial effects e.g. for flavan-3-ols is very strong (see e.g. Raman 2019 or Ried 2017) and the beneficial effect is broadly in line with other dietary interventions (such as Mediterranean diet).
 * A lot of what is stated here is clearly too speculative to put into the actual article - but the scientific background clearly shows that there is a fundamental misunderstanding regarding the current state of research.Ggux (talk) 04:56, 31 August 2022 (UTC)