Talk:Urtica dioica

Proposed changes

Hello, I have a suggested addition.

It is on my sandbox User:Adjerbi/sandbox, please have a look and tell me if something needs to be modified or improved.

It's my first major edit and I'm not sure linking my sandbox is the right way to suggest an edit, please feel free to correct me. It's supposed to be a new addition under "uses", and it will include the existing "traditional medicine" subsection. Adjerbi (talk) 13:20, 6 December 2022 (UTC)

@Adjerbi: thanks for not adding your material directly to the article; putting it in your sandbox and asking for comments is helpful. Unfortunately, very little of what you have drafted can be used in an article. You need to read WP:MEDRS carefully, and some of the pages linked at User talk:Zefr. You cannot add medical claims to Wikipedia unless they are sourced to the standards of WP:MEDRS, which basically means systematic reviews. Single studies in journal articles, claims of possible effects, etc. are all not allowed. You must not imply in vivo effectiveness from in vitro studies. Studies on mice can't be used to make claims of effectiveness in humans.

It's certainly desirable to say more about the use of nettle preparations in traditional medicine, but unless there are acceptable sources, you must not imply that they are effective in any way. Peter coxhead (talk) 15:05, 6 December 2022 (UTC)

Thanks for your insight, I have subsequently modified my suggested edit in my Sandbox. I removed any claim of efficacy in the traditional use subsection and only kept the information that they are used as traditional medicine without mentioning what they're supposed to cure as I hope that is what you meant by "desirable to say more about the use of nettle preparations in traditional medicine [without implying] that they are effective in any way" and I believe it now falls into the "general information" category instead of biomedical information (if not I'll just scrap this subsection altogether). I also found a source that aggregates results from the Committee on Herbal Medicinal Products and European Scientific Cooperative on Phytotherapy and cited it in the conventional medicine subsection as well as the corresponding assessment reports from the EMA (that are in any way cited as sources at the end of the website article). Please tell me any feedback you might have. Adjerbi (talk) 23:08, 13 December 2022 (UTC)

Poultry supplement sources are primary research

This disputed edit by Herrmannr is based on early-stage primary research represented in the proposed sources. It also contains misinformation that nettles are a dietary source of antioxidants. There is no WP:MEDRS evidence that nettles have any antioxidant or nutritional value in vivo as a feed supply. None of the sources provided indicates use of dietary nettles as a common practice in poultry farming, so remains WP:UNDUE. Further, Herrmannr is edit-warring, WP:3RR, and is warned to first obtain consensus on the talk page before further reverting per WP:BRD and WP:CON to establish consensus among other editors. Zefr (talk) 15:58, 13 December 2022 (UTC)

Nativity

According to Flora of North America, there are several subspecies, two of which are indeed native to North America. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220014002 98.118.134.179 (talk) 19:45, 7 June 2023 (UTC)

However, they are not currently accepted by Plants of the World Online as a subspeices of U. dioica. They classify one as the full species and the other as a subspeices as Urtica gracilis subsp. holosericea. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:286576-2 The text should certainly reflect that other sources continue to regard them as subspecies of U. dioica, but currently on Wikipedia we follow POWO for deciding what is or is not a "real" species. If no one else wants to do it I will get around to the issue of subsp. holosericea along with my ongoing cleanup to Urtica gracilis as a full species. MtBotany (talk) 20:19, 7 June 2023 (UTC)

Cystoliths

This article repeats the (extremely) oft-repeated claim that nettle cystoliths can cause urinary irritation (most also claim potential kidney stones.) I am unable to find any scientific sources of this information. The two sources cited are not scientific; the first (from which the claim is copied) makes the claim apparently without citation (though I don't have access to the full text.) Neither are scientific sources, AFAICT.

I'm not familiar with Wikipedia's policy on sources, so I have no opinion about the appropriateness of those works as citations for that claim, but I am troubled at the repetition of this information that appears (by my non-expert research) to be repeated without grounds.

So far, it seems that either the claim is false, and has just been copy/pasted on a million blog posts about nettles, or the claim is true and known only via oral tradition, in which case it doesn't seem appropriate that this article would present it in scientific terms.

Does anyone have thoughts on this, or any links to science that makes a link between cystoliths and kidney issues? Cystoliths are just calcium carbonate (i.e. chalk) and it seems unlikely that they could cause any problems.

Otherwise, I'd like to remove that caution from the article.

(Nettles seem likely to have some oxalic acid, though I can't find hard info on that either, so depending on how much of it is present, it might be appropriate to have a mention of that re: kidney stones.) Chconnor (talk) 23:20, 18 June 2023 (UTC)

Hello @Chconnor. If you want to fully understand Wikipedia's source policy you can read WP:SOURCE. A short summary is that the English Language version of wikipeda takes information from anything that is used as a reliable source. Non-reliable sources are those that are self-published or that contradict well established scientific consensus.

In this case the wording might be adjusted to either only reflect that the leaves contain cystoliths, which are unpleasant to eat since the causing urinary irritation is a medical claim. Though, it might be more useful to note the claim is commonly made, but without any specific medical study to back it, since if it is just taken out it is likely to be added back in by someone at a later date since it is commonly made in otherwise reliable books about wild food foraging.

If you want to research this further perhaps try searching for information about cystoliths and urinary irritation more generally rather than specifically about nettles.

Also, if there is any equally reliable sources that are not scientific in nature we would want that information in Wikipeida so that readers will know the information is uncertain. MtBotany (talk) 15:51, 19 June 2023 (UTC)

Thank you --I have searched in vain for any reference to CaCO3 cystoliths causing irritation of any kind. Bladder stones are sometimes referred to as cystoliths, but despite the name they are distinct (i.e. not CaCO3). I wonder if that's a source of confusion on the subject as well.

So this is an interesting conundrum and I wonder how Wikipedia handles this: when there is a profusion of "reliable" sources that are incorrect and not citing their own sources, it doesn't seem appropriate for an editor like me to make claims to the contrary. Additionally, if there is no explicit scientific consensus that cystoliths are safe because it hasn't been studied (even if there is no good argument to worry about it), then I can't argue that the numerous foraging guides making claims are contradicting well established science.

I assume there is no WP policy to allow me to add a paragraph like "Although this is often claimed, it is difficult to find any scientific evidence to back it up". So it would seem that WP is not the forum to remedy this prevalent (possibly/probably incorrect) information, which I can accept.

(And to follow up on my comment about oxalates above: nettles have only a little, so it does not sound like it's an issue: https://pubmed.ncbi.nlm.nih.gov/35807487/) Chconnor (talk) 19:33, 20 June 2023 (UTC)

@Chconnor I do think it would be appropriate to say there are no studies to support the contention. Wikipedia does have a very specific rule about medical claims, which I think this falls under. WP:MEDASSESS If you do not want to reword it I certainly will tag it with "medical citation needed". Though not today, I have sprained my wrist and this makes writing slow. MtBotany (talk) 20:32, 20 June 2023 (UTC)

@MtBotany thanks -- I sprained my shoulder so we're in a similar boat. No pressure to respond quickly. :-)

So, given that WP:MEDRS seems to say that medical claims require a more particular standard than the normal reliable sources policy, and that the current sources in the article do not appear to meet that standard, what if I reword the section, on those grounds, from this:

After the stinging nettle enters its flowering and seed-setting stages, the leaves develop gritty particles called cystoliths, which can irritate the kidneys and urinary tract.[37][39]106-107 Cystoliths are made of calcium carbonate, and will not dissolve when boiled. Leaves harvested post-flowering must have their cystoliths broken down by acid, as in the fermentation process.

To this:

After the stinging nettle enters its flowering and seed-setting stages, the leaves develop gritty particles called cystoliths. Many non-scientific sources caution that these can cause irritation of the kidneys or urinary tract [37][39]106-107, but these claims may not have any scientific backing.

I took out "Cystoliths are made of calcium carbonate, and will not dissolve when boiled." which I believe to be true, but which feels irrelevant if the warnings are unsupported.

I took out "Leaves harvested post-flowering must have their cystoliths broken down by acid, as in the fermentation process." as it was not cited at all, and seems to further allude to the unsupported claims of dangers of cystoliths, and ignores that stomach acid will also break down cystoliths. (source [40] at the end of that paragraph only applies to the protein content.)

If it seems appropriate, I'd also like to add "Confusion may stem from the fact that kidney stones and bladder stones are sometimes referred to using the same "cystolith" term, but they are chemically distinct" [a couple sources here]

Let me know your thoughts (when your wrist feels better.) Chconnor (talk) 20:28, 21 June 2023 (UTC)

@Chconnor I think you should be even firmer in the wording.

"After the stinging nettle enters its flowering and seed-setting stages, the leaves develop gritty particles called cystoliths. Many non-scientific sources caution that these can cause irritation of the kidneys or urinary tract [37][39]106-107, but these claims are not supported by scientific study." MtBotany (talk) 17:46, 22 June 2023 (UTC)

@Chconnor

I did finally get around to adding what I think is a good disclaimer. "Many sources claim consumption of these can irritate the kidneys and urinary tract, however there is no medical evidence to support this claim." What do you think? MtBotany (talk) 15:23, 9 July 2023 (UTC)

@MtBotany Thanks! I've been traveling so I hadn't gotten to it yet. Looks good to me. I do wonder if we should add something about nettle cystoliths being distinct from kidney cystoliths, though, as it seems a common confusion. Thoughts on that? I have some sources which don't address the distinction but do describe the chemical composition and show the difference. Chconnor (talk) 18:33, 10 July 2023 (UTC)

@User:Zefr, you reverted a change I made, but the sources are making a medical claim and not medical sources. If you have a medical source that says that cystoliths can cause kidney stones or urinary irritation, do add it. If you think my wording could be better, please alter it. But this needs to be clarified as it is a medical claim. See Wikipedia:Identifying reliable sources (medicine). MtBotany (talk) 15:57, 9 July 2023 (UTC)

Cystoliths (or cistoliths) are a term commonly used in bladder and kidney stone disorders as the piece of calculus that causes the pain. There is no practical way of studying whether consuming a nettle preparation a) leads to formation in vivo of a cystolith or b) induces formation of a cystolith that enters the bladder or urinary tract. Let's leave your wording as it is. Zefr (talk) 16:25, 9 July 2023 (UTC)

@Zefr - Bladder/kidney stone cystoliths are distinct -- they are not the same thing as the cystoliths in Nettles. See e.g. here: "In adults, the most common bladder stone composition is uric acid, which accounts for about 50% of cases. ... Other chemicals that form bladder stones include calcium oxalate, calcium phosphate, ammonium urate, cystine, and calcium-ammonium-magnesium phosphate (also called triple phosphate or struvite stones and are always associated with infection)." In contrast, nettle cystoliths are calcium carbonate, i.e. the same thing in most calcium supplements or multivitamins, i.e. chalk. Not known to cause any stones or urinary tract issues as far as all my searching has discovered. Nettles do have some oxalic acid (unrelated to the cystoliths and, as far as I can discover, flowering), but about half that of spinach and roughly the same as a carrot, i.e. not really a concern either in terms of stone formation. Chconnor (talk) 18:46, 10 July 2023 (UTC)

I wasn't implying that urinary tract cystoliths (commonly called "stones" - not actually rocks;>) are chemically the same as nettle cystoliths. In both cases (if consuming a nettle preparation actually causes a cystolith problem), pain is the only result to compare the two conditions, as nettles consumption in any form will not be studied in a systematic way. No organization would finance that. Zefr (talk) 18:53, 10 July 2023 (UTC)

Mechanics & chemicals in the stinging trichomes

1. Mechanics

The mechanics can be compared to the mechanism of a plastic pipette used in biochemistry: the tip penetrates through the skin and as the more the trichome gets bent, the more its content is emptied under pressure. [1]https://www.youtube.com/watch?v=VvvmGmat55Q&ab_channel=TomRocksMaths

1. Chemicals

"It is commonly thought that the compound which causes the pain is formic acid (the same substance which stinging ants inject) but that is now known to be untrue regarding Stinging Nettle." More on the list of chemicals: http://wildflowerfinder.org.uk/Flowers/N/Nettle%28Stinging%29/Nettle%28Stinging%29.htm

• silicon dioxide, Phytolith and/or Cystolith are also responsible for the sharp trichomes
• MONOAMINES
• serotonin, histamine and acetylcholine, but although all three are super-irritants, experimental injection under the skin still does not unleash the full stinging experience of nettles. Therefore other substance(s) must also be involved.
• MOROIDIN; consists of 8 differing moieties, 6 of them contained within two fused rings. The exocyclic moieties are PyroGlutamic Acid (bottom left corner) and Arginine, (top right). Attached to PyroGlutamic Acid on the first ring, and going clockwise, are: β-Leucine, Leucine, Valine and Tryptophan (with part of the Tryptophan molecule attaching at the top between Valine and Arginine). Those attached to the Arginine at top right, going clockwise, are Glycine and Histidine, which adjoins Tryptophan in the left ring. Have you got that?

These substances are bicyclic peptides and tend to be highly resistant to digestion within the stomach and can persist in the digestive tract. Although not present in Nettle, there also exists a plethora of other bicyclic polypeptides such as α-Amanitin, the highly toxic principle responsible for many fatalities after consuming Death Cap (Amanita phalloides) mushrooms. Cyclosporin A, a synthetic mono-cyclic polypeptide is used as an immunosuppressant drug in organ transplants. Echinomycin is another bicyclic polypeptide produced within various bacteria and is used medicinally as an antibiotic. There are hundreds more.

• LEUKOTRIENES

Thy for complementing, no more time, SvenAERTS (talk) 00:34, 11 July 2023 (UTC)