Talk:Curcumin

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Research distorted in this article

Several botanists brought to my attention that research is misrepresented in this article to the point of distortion. I read the linked articles and changed several sentences to reflect what the research said, quoting it directly. Overnight someone reverted those edits. One of the bloggers quoted in the original is a pharmaceutical company rep. but treated as an expert. That blogger does not identify where he works. That article, which is made central to the usefulness or lack of usefulness of curcumin, is a casual opinion piece with informal language, not at all rigorous science by any stretch of the imagination. That curcumin is unstable when isolated is proven. That it is useful for health reasons in certain diseases is carefully stated by the US National Institutes of Health. That curcumin is unstable means that the pharmaceutical industry has been unable to turn a profit on it. All of this was reverted overnight to reflect the Rx industry opinion. The reverts show how easy it is for someone stubborn enough and persistent enough to distort facts on Wikipedia without challenge. This is not a reliable article as it is based on deliberate distortions of what scientists have found. Anyone reading the linked articles will note that the ambiguity in the original articles is smothered in the Wikipedia article, and aspects treated as the whole and not a part of the research conclusions. Skywriter (talk) 18:29, 28 May 2018 (UTC)

In fact it is so highly unstable, that it vanishes before reaching its target. So, curcumin itself cannot have any therapeutic effects. This applies to both pharmaceutic usage as for natural intake of curcumin. Tgeorgescu (talk) 18:45, 28 May 2018 (UTC)

Derek Lowe is an expert in medicinal chemistry with a long record of doing, and writing about, med chem. Dismissing him as "a pharmaceutical company rep" is frankly stupid. (we actually have a page on him that i just found -- Derek Lowe (chemist).)

You do not bring a single source.

There is nothing to respond to. Jytdog (talk) 23:54, 28 May 2018 (UTC)

Frankly stupid? How collegial! How many Wiki rules do personal attacks violate, Jytdog?

Absolutely nothing you have stated changes the fact that Derek Lowe is a lifelong pharmaceutical industry representative. Is the opposite of that stupid? No, it just suggests you are prone to making personal attacks on Wikipedia editors with whom you disagree.Skywriter (talk) 15:57, 9 July 2018 (UTC)

Recent additions

The following was recently added:

However, a response published in Nature on March 1 to the January review noted that as of its publishing, "a PubMed search under 'curcumin double-blind placebo-controlled clinical trial' yields 49 entries, of which 17 recent trials show efficacy". Reviews have since found a wide variety of clinical effects of curcumin for chronic conditions.

Curcumin is not meaningfully bioavailable in humans when administered in isolation, because upon ingestion it is rapidly degraded via glucuronidation in the liver and intestinal wall; accordingly, compounds such as piperine, a known inhibitor of hepatic and intestinal glucuronidation, can increase curcumin bioavailabilty by 2000%.

References

The sourcing is not sufficient. Good WP:MEDRS sources are needed for content on health. Alexbrn (talk) 19:58, 30 May 2018 (UTC)

This isn't content on health. It makes no specific medically-actionable claims whatsoever that curcumin has even one iota of medical efficacy for anything, except insofar as a third-party reviewer has provided links to studies which say so, and reported their existence. It's primarily content on research methodology. It's documentation of a confounding factor regarding claims that past researchers have actually proven any absences. Moreover, it's four secondary-source reviews from four highly reputable institutions, three of which prove the existence of the phenomenon named, namely, that piperine improves curcumin bioavailability. I fail to see how these sources are anything but good.2610:130:104:200:9D91:3A68:3C47:20F (talk) 20:09, 30 May 2018 (UTC)

It is WP:Biomedical information, which requires WP:MEDRS sourcing. Alexbrn (talk) 20:14, 30 May 2018 (UTC)

All four sources are: independent; secondary sources; from reputable institutions; summarizing scientific consensus; which avoid over-emphasizing single sources; published using up-to-date evidence. How the bloody hell is that *not* WP:MEDRS sourcing?2610:130:104:200:9D91:3A68:3C47:20F (talk) 20:19, 30 May 2018 (UTC)

We don't use "comments" (which is what the first source, PMID 28252078, is) to discount MEDRS sources. Ever. See WP:MEDREV on this. That is classic tendentious editing, and there is no way you will get this badly sourced content into the article. You really need to pay attention to MEDRS and summarize what MEDRS sources say. We all get it that you believe in curcumin. Jytdog (talk) 20:26, 30 May 2018 (UTC)

And (though they're so poorly cited it's necessary to check) the others appear to be out-of-date or off-topic. We are already using a 2017 review article. Alexbrn (talk) 20:32, 30 May 2018 (UTC)

As far as I'm aware, chemistry does not change over time. Nevertheless, I have just added three reviews which took place after the review mentioned, all of which found clinical evidence of the efficacy of curcumin. I am unclear why you accuse me of "belief", but c'est ça. Do these constitute MEDRS sources?2610:130:104:200:9D91:3A68:3C47:20F (talk) 21:15, 30 May 2018 (UTC)

Also, since I have no idea what you people want regarding psychoanalyzing my motivations, I'm just gonna leave the source that led me to make any edits at all here. If you need to write a section about their malpractice, so that you may conflate evidentiary-completeness with genuine malefactors, feel free: http://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/curcumin#authors-reviewers — Preceding unsigned comment added by 2610:130:104:200:9D91:3A68:3C47:20F (talk) 21:39, 30 May 2018 (UTC)

It lists six articles by Aggarwal, who has a conflict of interest and has produced fraudulent research (now retracted). Tgeorgescu (talk) 21:49, 30 May 2018 (UTC)

6 of 123. The first citation of Aggarwal is for this claim: "Curcumin, the principal curcuminoid found in turmeric, is generally considered its most active constituent". The second citation of Aggarwal is for this claim: "In the intestine and liver, curcumin is readily conjugated to form curcumin glucuronide and curcumin sulfate or, alternately, reduced to tetrahydrocurcumin, hexahydrocurcumin, and octahydrocurcumin (Figure 2)". The fourth citation of Aggarwal is for this claim: "Examples of approaches include conjugation to peptide carriers (e.g., to polylactic-co-glycolic acid [PLGA]); complexation with essential oils; coadministration with piperine; and encapsulation into nanoparticles, liposomes, phytosomes, polymeric micelles, and cyclodextrins". The third and fifth citations of Aggarwal are paired with others. The sixth citation of Aggarwal is this claim: "Turmeric is the dried ground rhizome of Curcuma longa Linn (106)."

I'm sure it's quite the scandal that they didn't bother updating their source for the definition of turmeric. — Preceding unsigned comment added by 2610:130:104:200:9D91:3A68:3C47:20F (talk) 22:10, 30 May 2018 (UTC)

The gist is that Aggarwal should not be jury, judge and executioner over his own patented medicines. Tgeorgescu (talk) 22:17, 30 May 2018 (UTC)

These kind of extensive research fraud cases are so hard. It is going to take several years for the field to rethink what we know and what we don't know, especially in terms of in vivo activity. In other words, current secondary sources about biological activity and efficacy need to be read... cautiously as it will take time for the rethinking to be expressed in them. In the meantime, the cautions raised by medicinal chemists based on the chemistry and in vitro results are all the more important. Jytdog (talk) 22:21, 30 May 2018 (UTC)

Agreed, and in addition to the cautions, we must also take seriously the body of evidence that remains after removing Aggarwal's data e.g. that which makes up the Linus Pauling Institute's review. As noted by the cabal-approved parts of this article, there's been a shit-ton of research into this thing, probably more than merited. Let's not waste it.2610:130:104:200:9D91:3A68:3C47:20F (talk) 22:46, 30 May 2018 (UTC)

The shit-ton of clinical research is all unfortunately weak and constantly hyped with woo of "promise". So much money has been thrown away on this. Jytdog (talk) 22:50, 30 May 2018 (UTC)

I've offered multiple meaningful secondary sources from world-class research journals regarding the pharmacokinetics of curcumin. When they were from before Aggarwal, they were determined to be "not up to date". When they were from after, it was assumed they should be mistrusted because of Aggarwal's existence, even when their citations of him were passive-aggressively superficial. You offer no way around this catch-22. My note on pharmacokinetics was most recently taken down for "not being replicable", which I assume is why I just found yet another systematic review from a major research journal mentioning the existence of exact mechanism I mentioned, one without meaningful Aggarwal citations.

Ha! Guess what I just read? That "unverifiable" phenomenon I named, glucuronide degradation, is explicitly named in the very same Nelson citation that y'all cited three times for its claim of no clinical efficacy. Are we to assume that this "unverified" claim makes this source unreputable? Because if so, your own beliefs (can I call them that?) are derived from a single source back in 2017. "The most abundant conjugates are glucuronides and sulfates at the phenolic positions." -Nelson, 2017 2610:130:104:200:9D91:3A68:3C47:20F (talk) 23:39, 30 May 2018 (UTC)

So not everyone thinks alike. I didn't understand this edit by User:Rhode Island Red - RiR would you please explain why you removed all of that? (the prior edit was fine with me btw) Jytdog (talk) 23:52, 30 May 2018 (UTC)

As stated in the edit summaries, the first half failed verification (was not in the cited source). The second half is a case of WP:UNDUE and reliance on what is ultimately a single study (Shoba et al. 1998) about piperine (a black pepper constituent) that's given undue prominence -- i.e., it doesn't matter that a couple of sources among thousands of articles on curcumin bioavailability have cited it, it’s still a single study AND it was in 10 subjects AND it happens to be from a spice extract nutraceutical company in India (SAMI Chemicals & Extracts) AND it was in an obscure journal (Planta Medica) AND it was published 20 years ago. So, yeah, bit of an issue with using WP to carry water for pepper extract merchants ;> Rhode Island Red (talk) 00:39, 31 May 2018 (UTC)

Actually on closer inspection of the Shoba study, it was only 8 subjects, not 10 (2 dropped out) AND I forgot to mention that the study was not placebo-controlled or blinded AND the dose of curcumin was 2 g per kg, which corresponds to eating more than a whopping quarter pound of curcumin for an average (70 kg) man, a completely irrelevant paradigm. Rhode Island Red (talk) 00:59, 31 May 2018 (UTC)

Nobody is contesting the first edit and i explictly said that. You did not explain the second, and I am reverting. Jytdog (talk) 01:15, 31 May 2018 (UTC)

I have said twice now that it failed verification (was not in the cited source). Oh, and sorry about misreading about the second part about piperine. I thought you were disputing that as well but just noticed it wasn't in the diff edit you posted. My bad. Cheers Rhode Island Red (talk) 01:42, 31 May 2018 (UTC)

Am I missing something here. I keep removing this text and explaining that it is not in the source cited and you keep restoring it.[1] What is the issue? Rhode Island Red (talk) 02:08, 31 May 2018 (UTC)

Better now -- a world of difference.[2]

• IP hopper per the discussion above there is no consensus. I am asking to have this page protected. Jytdog (talk) 17:58, 5 June 2018 (UTC)