Talk:Saturated fat/Archive 4

Cochrane and AHA

I tried to verify the following sources [1] and [2] from the section on mortality and found that they offer a lot more than just mortality and the AHA wasn‘t even summarized correctly.

These are high-quality sources and they can be used in the article. However, instead of cherry-picking a single clinical endpoint they should be summarized in all their breadth.

I will also add that picking only mortality can be heavy POV, because it sounds as if SAF bring no health issues while in reality people get sick with CVD and are duct-taped together to live as long as people without CVD. (Disclaimer: before someone calls me out on POV, I love duct tape.) CarlFromVienna (talk) 10:42, 27 December 2022 (UTC)

Vandalism of this talk page

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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An editor is reverting good-faith comments on this saturated fat talk page. See edit history.sbelknap (talk) 14:12, 27 December 2022 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

MDPI journals for startling claims

An editor removed content that cited an article in Nutrients apparently on the basis of WP:OR by this editor regarding the journal's publisher, MDPI. Notably, the journal Nutrients was one of the top 200 journals cited in wikipedia according to multimedia appendix 2 in this article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356187/

Here is the link to the inappropriate deletion of this material: https://en.wikipedia.org/w/index.php?title=Saturated_fat&oldid=1129925191

I request that this editor stop applying their original research as a criteria for their editing. I request that the content with cites be restored for this deletion and also for the other inappropriate deletions that we have seen w/r/t the saturated fat article.sbelknap (talk) 23:08, 27 December 2022 (UTC)

Don't be daft. WP:OR does not apply to discussion of whether a source is reliable. Making such assessments is a cornerstone of competent Wikipedia editing, and in fact there is a whole noticeboard for that where, incidentally, MDPI has been much discussed: see WP:MDPI. Bon courage (talk) 07:27, 28 December 2022 (UTC)

Expansion of "Cardiovascular disease" section

I've moved the recent expansion from the article [3]:

A review of 11 meta-analyses bearing on the association between saturated fat and mortality found that only 2 of the 11 reported a mortality benefit from interventions that lowered dietary saturated fat. These authors concluded that diets low in saturated fat that reduce serum cholesterol do not prevent deaths. Specifically, diets that replace saturated fat with polyunsaturated fat do not convincingly reduce cardiovascular events or mortality. The authors note that their conclusions contradict current opinion.

References

I'm concerned that it's being given UNDUE weight. Even if used, it needs rewording for clarity. --Hipal (talk) 00:15, 28 December 2022 (UTC)

The text is a paraphrase of the main findings of the article. It is accurate. If you have a rephrase, great. I will restore the text as written, as you have given no specific request for a change. sbelknap (talk) 01:23, 28 December 2022 (UTC)

The BMJ article is identified as "opinion and debate", i.e., it is not a WP:MEDRS review, and is a minority position which has not gained significant scientific agreement, so is WP:UNDUE. Zefr (talk) 03:28, 28 December 2022 (UTC)

Given the type of article, it's grossly undue. --Hipal (talk) 03:36, 28 December 2022 (UTC)

This is not a BMJ article. Instead, it appears in a different journal which is named, "BMJ Evidence-based Medicine." It is a review of the available 17 meta-analyses on this topic. The chief result is that most of these meta-analyses find that diets low in saturated fat do not prevent deaths. The removal of this content with citation from the saturated fat article does not appear to have any rational justification. Here is the link: https://ebm.bmj.com/content/26/1/3 sbelknap (talk) 04:01, 28 December 2022 (UTC)

I'm afraid that assessment is incorrect. It's identified as "opinion and debate". It's grossly undue as such. --Hipal (talk) 04:20, 28 December 2022 (UTC)

Perhaps you are unfamiliar with this journal and have not read the article. I have taught evidence-based medicine to medical students for 30 years. I've published in the journal Evidence-based Medicine. I've published meta-analysis articles. I've served as a peer-reviewer for journals. I'm also an experienced wikipedia editor.

BMJ Evidence-based medicine presents rigorous discussions of medical evidence. The subject matter of this article are the 17 meta-analyses on this topic. This review article is a high-quality secondary source. It presents important information that is directly relevant to this wikipedia article.

The rejection of this article is absurd, as is the rejection of the other half-dozen I've attempted to add.

What is to be done? sbelknap (talk) 04:36, 28 December 2022 (UTC)

You can address the concerns directly instead of telling us what an expert you are. --Hipal (talk) 17:42, 28 December 2022 (UTC)

Outdated reading

This section below - removed from Further reading - is too outdated to represent the mainstream current science on the topic. The guidelines of numerous clinical and government organizations serve this purpose. See WP:MEDSCI ("summarize scientific consensus") and WP:MEDDATE.

• Feinman RD (October 2010). "Saturated fat and health: recent advances in research". Lipids. 45 (10): 891–2. doi:10.1007/s11745-010-3446-8. PMC 2974200. PMID 20827513.
• Howard BV, Van Horn L, Hsia J, et al. (2006). "Low-fat dietary pattern and risk of cardiovascular disease: the Women's Health Initiative Randomized Controlled Dietary Modification Trial". Journal of the American Medical Association. 295 (6): 655–66. doi:10.1001/jama.295.6.655. PMID 16467234.
• Zelman K (May 2011). "The great fat debate: a closer look at the controversy-questioning the validity of age-old dietary guidance". Journal of the American Dietetic Association. 111 (5): 655–8. doi:10.1016/j.jada.2011.03.026. PMID 21515106.

Zefr (talk) 04:52, 28 December 2022 (UTC)

It is not the case that Wikipedia depends on guidelines as the chief sources to cite in support of content in medical articles. Instead, Wikipedia relies on secondary sources (and tertiary sources, when these are available). When there are strong primary sources, those are OK as well. There is also clear evidence in the literature of serious flaws in the Dietary Guidelines for Americans with regard to recommendations on dietary saturated fat.

The Women's Health Initiative Randomized Controlled Dietary Modification Trial is a strong primary source. In my view, it remains relevant. The Zelman review remains relevant. So does the Feinman article. Here we see arbitrary decisions where some articles are deemed "old" and deprecated for reasons that are unclear.

Meanwhile, we are neglecting the large and growing medical literature showing that the quality of evidence is very poor regarding the association between bad health outcomes and saturated fats. A systematic effort has been underway for years to resist the inclusion of such articles, even when they are of high quality. This is bizarre. What is going on? sbelknap (talk) 05:33, 28 December 2022 (UTC)

If the organizations mentioned in the first paragraph here were to change their guidelines - the basis of WP:MEDSCI for presenting the prevailing scientific consensus - then we would have reason to acknowledge alternative concepts. Meanwhile, the 3 articles above are weak, outdated sources providing little value to the general user. See WP:MEDMOS, audience. Zefr (talk) 05:52, 28 December 2022 (UTC)

This is not consistent with the custom and practice of wikipedia w/r/t content of medical articles. We use mostly secondary sources. sbelknap (talk) 05:55, 28 December 2022 (UTC)

We use government and clinical practice guidelines as the highest-quality sources which consolidate the secondary review literature; see WP:MEDASSESS, top of left pyramid. Zefr (talk) 06:02, 28 December 2022 (UTC)

Indeed, these are golden sources for us. Bon courage (talk) 07:29, 28 December 2022 (UTC)

At WP:MEDASSESS we find this: "When writing about any health effect, assessing evidence quality helps distinguish between minor and major views, determine due weight, and identify accepted evidence-based information. Even in reputable medical journals, different papers are not given equal weight. Studies can be categorized into levels of evidence,[6] and editors should rely on high-level evidence, such as systematic reviews. Medical guidelines or position statements by internationally or nationally recognized expert bodies also often contain recommendations, along with assessments of underlying evidence (see WP:MEDORG). The best evidence for efficacy of treatments and other health interventions is mainly from meta-analyses of randomized controlled trials (RCTs).[10] Systematic reviews of literature that include non-randomized studies are less reliable.[11] Narrative reviews can help establish the context of evidence quality. The best evidence for efficacy of treatments and other health interventions is mainly from meta-analyses of randomized controlled trials (RCTs).[10] Systematic reviews of literature that include non-randomized studies are less reliable.[11] Narrative reviews can help establish the context of evidence quality."

There is a figure at WP:MEDASSESS with two pyramids which present contradictory information: the one on the left puts clinical practice guidelines at the top of the evidence hierarchy and cites a dead link and a outdated link. Clicking on the outdated link reveals that that the current version of the pyramid at the source does not place clinical practice guidelines at the top of the evidence hierarchy but instead places systematic reviews and meta-analysis at the top of the hierarchy. It is therefore the case that some engaged editors here are relying on a deprecated pyramid in the WP:MEDASSESS wikipedia article which differs from the one at the cited source. Here is the pyramid from the current version of the source https://libapps.s3.amazonaws.com/accounts/174160/images/pyramid12.jpg sbelknap (talk) 12:38, 28 December 2022 (UTC)

Thus, it is simply not the case that wikipedia editors working on medical articles on wikipedia are to consider clinical practice guidelines as a higher level of evidence than systematic reviews plus meta-analysis or other types of secondary sources. This repeated assertion that clinical practice guidelines, society position statements, and the like are to be considered the highest level of evidence. This is false. The text at [[WP:MEDASSESS] does not place clinical practice guidelines at the top of the hierarchy. The figure being quoted as authoritative here on this Saturated fat talk page has been deprecated and the figure is currently in error at [[WP:MEDASSESS].

Now that we've cleared up this misunderstanding, let us revise this saturated fat article so as to rely on high-quality secondary sources, such as systematic reviews and meta-analyses. Tertiary reviews (e.g., umbrella reviews or reviews of meta-analyses) may also play a useful role. Primary sources in some cases may also be cited in certain circumstances, as is discussed in various wikipedia guidelines. sbelknap (talk) 12:48, 28 December 2022 (UTC)

The positions of major national/international bodies make ideal WP:MEDRS. Bon courage (talk) 12:54, 28 December 2022 (UTC)

That is not what the guidelines at WP:MEDASSESS tell us. Not at all. You are welcome to reread the guidelines at WP:MEDASSESS, including the deprecated hierarchy of evidence presented there, click through to the current pyramid at the source and thus revise your misinformed opinion.

Here at wikipedia, editors are to rely on high-quality secondary sources, such as systematic reviews & meta-analyses whenever possible. There is often a useful role for umbrella reviews, primary studies, society recommendations, clinical practice guidelines, etc. However, wikipedia policy for editing medical info is to give preference to citing high-quality secondary sources. sbelknap (talk) 12:59, 28 December 2022 (UTC)

You're wrong, but welcome to raise it at WT:MED if you seek some kind of shortcut to WP:CLUE. Or even review some of the recent discussions there about sourcing. At the top of the page MEDRS helpfully includes "medical guidelines and position statements from national or international expert bodies" among the list of ideal MEDRS. Bon courage (talk) 13:08, 28 December 2022 (UTC)

I am an experienced editor. Here is the relevant text from MEDRS [4]

"Ideal sources for biomedical information include: review articles (especially systematic reviews) published in reputable medical journals; academic and professional books written by experts in the relevant fields and from respected publishers; and guidelines or position statements from national or international expert bodies."

What part of "especially systematic reviews" are you struggling with?

The wikipedia policies are clear. Perhaps you might adhere to them. sbelknap (talk) 14:59, 28 December 2022 (UTC)

WP:CLEARLY not. Systematic reviews are preferred to narrative ones, yes. Bon courage (talk) 15:23, 28 December 2022 (UTC)

There is something wrong here.

I have presented content citing a half-dozen systematic reviews with meta-analyses as new edits to this Saturated fats page. Various editors have objected to these giving specious reasons. Various editors have claimed that clinical practice guidelines are preferred over systematic reviews and other secondary sources.

I'm hoping that correcting this misunderstanding leads to improvements in this Saturated fats article, which is in a sorry state of disrepair at the moment. sbelknap (talk) 15:44, 28 December 2022 (UTC)

Rewrite of lede

At very best, this rewrite does not appear directed at Wikipedia's audience. It doesn't appear to follow WP:LEDE either. --Hipal (talk) 17:59, 28 December 2022 (UTC)

The lead was verbose and lacked important detail. The rewrite is written to a US 6th grade level. It is directed at the laymen. If you have a specific suggestion, then make it. sbelknap (talk) 18:04, 28 December 2022 (UTC)

I'd rather just leave it as is. If you want to make a case for any of the changes, it would help. --Hipal (talk) 18:12, 28 December 2022 (UTC)

sbelknap's version was a jargon mess. Wikipedia is not an encyclopedia for experts, but rather serves the general user, WP:NOTTEXTBOOK #6-7, and WP:MEDMOS, here. Please stop your disruptive editing, take a break from this article, and go explore/edit other content. Zefr (talk) 18:15, 28 December 2022 (UTC)

Please be specific. Which jargon are you referring to? My version was directed at the general user of wikipedia. I am an experienced wikipedia editor and have contributed to many medical articles. sbelknap (talk) 18:17, 28 December 2022 (UTC)

I agree with Zefr. --Hipal (talk) 18:24, 28 December 2022 (UTC)

My edits are clearly in good faith. Why am I being attacked on my talk page? sbelknap (talk) 18:32, 28 December 2022 (UTC)

The current lede contains this sentence:

"A double bond along the carbon chain can react with a pair of hydrogen atoms to change into a single -C-C- bond, with each H atom now bonded to one of the two C atoms."

This sentence is difficult to parse, off-topic and unnecessary in the lede. I recommend it be deleted. sbelknap (talk) 18:38, 28 December 2022 (UTC)

The first sentence in the second paragraph is not informative. For example, the fat in typical grocery store beef is about 50% saturated fat, 45% monounsaturated fat, and 5% polyunsaturated fat. I have edited it to be more accurate.sbelknap (talk) 18:57, 28 December 2022 (UTC)

There is mention of hydrogenated fat in the lead but this is not presented well. Transfat is discussed in the body of the article, but the presentation is incoherent. It seems to me that the next place to do work is in the body of the article regarding transfat and hydrogenated fat. Some of this info can then be summarized in the lede.

This article needs extensive work. There is a lot of potential for improvement. Are any other editors interested in making good-faith productive edits?sbelknap (talk) 19:17, 28 December 2022 (UTC)

Please work here to gain consensus. You're edit-warring. Please stop making comments about other editors, especially ones that fail to assume good faith.

I'm unclear what the second paragraph (in either version) is based upon from the article body. That's definitely problematic. --Hipal (talk) 19:42, 28 December 2022 (UTC)

I am an experienced editor engaged in good faith edits on this page. If you have something useful to add, do so. sbelknap (talk) 20:25, 28 December 2022 (UTC)

I think it best we have you blocked or banned from this article. You're far too disruptive and hostile to others. Sorry you refused to discuss the matter on your talk page. --Hipal (talk) 21:07, 28 December 2022 (UTC)

My focus is on improving wikipedia. Stay well. sbelknap (talk) 23:34, 28 December 2022 (UTC)

NPOV dispute - article does not discuss benefits vs. common alternatives

User Zefr repeatedly reverts my contributions, where I compare saturated fat to omega-6 and carbs. He claims that the well-known studies I cite are "not reliable" or "do not reflect consensus". Of course nutrition is controversial (the reasons for this are well understood). That doesn't mean prevailing viewpoints should be blocked. Unsigned by IP 108.185.180.195

Correct. Read the above talk topics and article history over the past many years to see the editorial (and scientific) consensus; WP:QUACKS. Do not drop unwarranted notices. Zefr (talk) 19:43, 6 June 2023 (UTC)

Fine, but what your repeated revisions amount to is "Zefr's view is right therefore the article shouldn't cover any other views" and that is not constructive. Let me know when you have a constructive contribution. Unsigned by IP 108.185.180.195

Article and talk page histories show the involvement of many editors and MEDRS sourcing for the article content as it existed before your disruptive, non-consensus edits today. What specifically is your NPOV issue?

You added this 10-year old cohort study and limited meta-analysis which has been superceded by several newer sources, with prevailing scientific consensus as stated in the article. You added this low-carbohydrate diet study which has nothing to do with saturated fat. Zefr (talk) 20:45, 6 June 2023 (UTC)

108.185.180.195 has been blocked but I agree this user was adding off-topic and unreliable sources. The low-carb meta-analysis if you read it, the trials were all less than 6 months. It tells us nothing about mid-term or long-term cardiovascular health and is not about the topic of this article. Psychologist Guy (talk) 21:44, 6 June 2023 (UTC)

"Saturated fat and cardiovascular disease" listed at Redirects for discussion

The redirect Saturated fat and cardiovascular disease has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 August 28 § Saturated fat and cardiovascular disease until a consensus is reached. Mdewman6 (talk) 22:54, 28 August 2023 (UTC)

"Arterycloggingsaturatedfat" listed at Redirects for discussion

The redirect Arterycloggingsaturatedfat has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 August 28 § Arterycloggingsaturatedfat until a consensus is reached. Mdewman6 (talk) 22:57, 28 August 2023 (UTC)

"Cardiovascular disease and saturated fat" listed at Redirects for discussion

The redirect Cardiovascular disease and saturated fat has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 August 28 § Cardiovascular disease and saturated fat until a consensus is reached. Mdewman6 (talk) 23:08, 28 August 2023 (UTC)

NPOV dispute - Research showing no link between saturated fat and CV risk is missing from this article

This paper was published September, 2022. It unfortunately does not fit popular opinion despite utilizing scientific rigor. I assume that's the reason for its exclusion. https://academic.oup.com/eurjpc/article-abstract/29/18/2312/6691821

It came to the same conclusion this meta-analysis did in 2014: https://www.acpjournals.org/doi/10.7326/M13-1788?articleid=1846638

Which came to the same conclusion this meta-analysis did in 2010: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824152/

(The point is to illustrate that this has been an ongoing debate for at least 12 years.)

Apparently the science is not so clear cut on the relationship between saturated fat and CV risk, but that's not the impression someone reading this article would get. Are we going to present all the scientific data, or are we taking sides? Agenda or no? 2600:4040:5012:7500:3000:9EF2:F8B5:125A (talk) 13:29, 26 March 2023 (UTC)

2014 is old, but the more recent paper might be worth mentioning. Or is it just an outlier? We cite WHO stuff which is more recent. Bon courage (talk) 13:56, 26 March 2023 (UTC)

The best sources on this are the World Health Organization (2023) [5], American Heart Association [6] (2017), UK Scientific Advisory Committee on Nutrition (2019), [7] and Cochrane review (2020) [8]. In total they have looked at hundreds of studies. The scientific consensus is clear on this, high saturated fat intake does increase CVD risk. Psychologist Guy (talk) 16:15, 26 March 2023 (UTC)

We have about 60 years research on this, it has been known for a long time since the research of D. Mark Hegsted and colleagues that palmitic acid increases LDL-c and total cholesterol. The debate has continued in recent years about specific saturated fatty acids on CVD risk. Long-chain saturated fatty acids increase CVD risk (palmitic and myristic acid for example) but stearic acid a medium-chain saturated fatty acid is neutral or may lower LDL. It's probably worth mentioning this on the article at some point. The World Health Organization have discussed it. Psychologist Guy (talk) 16:38, 26 March 2023 (UTC)

Yeah, Cochrane is a always a great source. Let’s see what it actually said:

“ We found little or no effect of reducing saturated fat on all‐cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate‐quality evidence.

There was little or no effect of reducing saturated fats on non‐fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low‐quality evidence), but effects on total (fatal or non‐fatal) myocardial infarction, stroke and CHD events (fatal or non‐fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.” Antisoapbox (talk) 21:41, 9 June 2023 (UTC)

Hopefully you have read that review, rather than just the abstract. Firstly, the trials in most cases were only two years long and they were on "participants at varying levels of risk of cardiovascular disease, men and women, with mean ages from 46 to 66 years". But you deliberately left out "There is a large body of evidence assessing effects of reducing saturated fat for at least two years. These studies provide moderate‐quality evidence that reducing saturated fat reduces our risk of cardiovascular disease" and "In this review, saturated fat reduction had little or no effect on all‐cause or cardiovascular mortality but did appear to reduce the risk of cardiovascular events by 17%". The conclusion is that reduction of saturated fat reduced risk of cardiovascular events in the participants that had or were at risk of cardiovascular disease by 17%. If you have any Cochrane reviews telling us the opposite that increased saturated fat consumption reduces cardiovascular events, let us know but no such finding has ever been published because saturated fat clearly increases CVD risk and yes it takes decades, not two years but those trials have shown us reducing CVD for around two years can reduce CVD events. Psychologist Guy (talk) 23:48, 9 June 2023 (UTC)

Here is a major study: [9]. The conclusion is: "In this cohort, substituting omega 6 linoleic acid for saturated fat did not provide the intended benefits, but increased all cause morality, cardiovascular death, and death from coronary heart disease." A recent meta-analysis -- included in the provided link -- addresses more recently raised concerns, and reaffirms the original result. Therefore exclusion of this result is an NPOV issue.

With every food investigated in nutrition there will always be an outlier study. There is no point in cherry picking 1 study or meta-analysis when every other meta-analysis and review says the opposite as you are ignoring consensus. The study you are quoting is from 2013. We since have many recent reviews published between 2014 and 2023 which conclude linoleic acid consumption lowers risk of CVD and mortality [10], [11], [12], [13]. Psychologist Guy (talk) 21:40, 6 June 2023 (UTC)

It is undeniable that the wikipedia article on saturated fat violates NPOV.

"Available evidence from adequately controlled randomised controlled trials suggest replacing SFA with mostly n-6 PUFA is unlikely to reduce CHD events, CHD mortality or total mortality. The suggestion of benefits reported in earlier meta-analyses is due to the inclusion of inadequately controlled trials. These findings have implications for current dietary recommendations.".

Source: doi.org/10.1186/s12937-017-0254-5 sbelknap (talk) 20:59, 9 September 2023 (UTC)

You already cited that paper before on the red meat talk-page. It's a bit silly to be talking about CHD mortality or total mortality from randomized controlled trials that are around a year and a half long. There is no long-term clinical data. Of course there will be no signifcant effect here. Total mortality is not something that can be studied within a year from a couple of short-term trials. The best evidence that we have for this are epidemiological studies that look at decades of data and show consistent results. Psychologist Guy (talk) 20:53, 10 September 2023 (UTC)

You have misstated the findings of the Hamley meta-analysis. Perhaps you have not read it. Is this one behind a paywall for you?

If you have access to the article, look at Figure 6.

Poor-quality RCTs show that switching satfat → PUFA *reduces* CHD mortality while the high-quality RCTs show switching satfat → PUFA *does not reduce* CHD mortality.

I propose that the findings of Hamley be included in this wikipedia article on Saturated Fat. sbelknap (talk) 22:21, 10 September 2023 (UTC)

Most controlled trials will not give us good results for CHD mortality or total mortality because nearly all of the controlled trials are short-term. Hopefully you realise this. We need long-term data, that is why we rely on epidemiological studies here.

Many of these short-term trials that the author you cite mentions are between 1 and 2 years. In a human lifetime that is a short time. It will not give us significant data about mortality. The paper you are talking about by Steven Hamley is online in full [14]. The review he is criticizing is the Hooper review [15]. The Hooper review reported that there was little or no effect of reducing saturated fat on all‐cause mortality or cardiovascular mortality. The reduction was in cardiovascular events. It is not our purpose here to be doing original research like Steven Hamley has been doing. The Hooper review is a high-quality source and is cited on the article. There is no reason to cite a weak source like Steven Hamley. If like Hamley you believe certain controlled trials are "inadequate" that is up to you, but this type of original research will not be put onto the article. It is not up to us to question reliable reviews here, we just report what they say. The Hooper review is cited on the article. Psychologist Guy (talk) 00:22, 11 September 2023 (UTC)

I've published two meta-analyses. I'm familiar with how this is done.

Hamley's meta-analysis is a separate analysis and is not a commentary on the Hooper review. He does critique prior meta-analyses, including Hooper. This is a routine part of a meta-analysis & systematic review. Hamley does a more comprehensive analysis than Hooper, as he studies how different types of studies compare.

In the methods section of Steven Hamley's meta-analysis, he states, "I followed the PRISMA (www.prisma-statement.org) guidelines [52] throughout the design, implementation, analysis, and reporting of this meta-analysis."

Hamley does follow the PRISMA guidelines. Hooper does not follow the PRISMA guidelines. For these and other reasons, the Hamley review is of higher quality than the Hooper review.

This article could be improved by including the points made by Hamley. sbelknap (talk) 04:02, 11 September 2023 (UTC)

Ramsen and Hamley both deal with the question whether SFA should be replaced primarily with omega 6. Ramsen concludes that

"RCT that substituted mixed n-3/n-6 PUFA in place of TFA and SFA reduced CHD risk. By contrast, n-6 specific PUFA interventions tended to increase CHD risk.".

Hamley concludes that

"By contrast, n-6 specific PUFA interventions tended to increase CHD risk."

Both authors are looking for the best way to replace SFA and conclude that a replacement with primarily omega 6 does not reduce risk. Based on these two studies it seems that replacing SFA with a mix of omega 3 and omega 6 is the best strategy to reduce CVD risk. CarlFromVienna (talk) 09:26, 11 September 2023 (UTC)

You are correct that Hamley & Ramsen have different conclusions. Thanks for sharing your original research. As you know, editors are not to cite their own original research for content in wikipedia articles. Neither Hamley nor Ramsen draw the conclusion you state, that "replacing SFA with a mix of omega 3 and omega 6 is the best strategy to reduce CVD risk."

The way ahead with this article is to cite Hamley's findings. sbelknap (talk) 11:40, 11 September 2023 (UTC)

Hamley seems to be using some subjective criteria about what he classifies as a "adequately controlled trial" and the ones which are "inadequate" in his view. The adequate trials all seem to support his POV. For example this 1965 trial that used corn oil [16] was using high-dose corn oil in supplement form. The conclusion of this trial is that there was no benefit. This is not surprising. The subjects were consuming corn oil capsules, not a healthy diet. This is in contrast to another trial he cited that involved a plasma-cholesterol-lowering diet that included soybean oil, fish and vegetables [17], the conclusion was "the cholesterol-lowering diet reduced the incidence of total CHD". Yet Hamley excludes this trial as "inadequate". Why would we cite an article by Hamley that does original research?

I would agree that replacing SFA with a mix of omega 3 and omega 6 is a good strategy to reduce CVD risk. The scientific consensus is telling people to consume a mixture of n-3/n-6 PUFA in place of SFA. The idea to include just n-6 or "mostly" n-6 is not the consensus view. Hamley seems to be misrepresenting scientific consensus. The consensus view is very clear, we do not need to add one opinion piece from Hamley challenging it. See WP:Fringe. Psychologist Guy (talk) 11:58, 11 September 2023 (UTC)

Here, you misstate Hamley's methods, describing his criterion for "adequately-controlled" as being subjective. You also mischaracterize Hamley's article as "an opinion piece." Hamley is conducting and reporting meta-research and review in his article. If one follows his process, one obtains the same meta-research result. Perhaps you are unfamiliar with PRISMA. The failure of the Cochrane group to distinguish RCT quality is a deviation from PRISMA, which perhaps accounts for why the Cochrane meta-analysis does not claim adherence to PRISMA.

In the methods section, Hamley describes the criterion he used:

"Clinical trials were identified from earlier meta-analyses. Relevant trials were categorised as ‘adequately controlled’ or ‘inadequately controlled’ depending on whether there were substantial dietary or non-dietary differences between the experimental and control groups that were not related to SFA or mostly n-6 PUFA intake, then were subject to different subgroup analyses."

Hamley excludes the Oslo Diet Heart study because of a dietary difference between the experimental and control groups that was unrelated to SFA or (mostly) ω-6 PUFA intake—trans fatty acids: that is, in the Oslo Diet Heart study, "only the experimental group (the high n-6 PUFA group) received advice to avoid major sources of industrial trans fatty acids (TFA), such as common/hard margarines, shortenings and/or hydrogenated oils." This info is presented by Leren et al in the primary source. There is nothing subjective or original about Hamley's exclusion of the Oslo Diet Heart study. In fact, this critique of the Oslo Diet Heart study is well-known.

These objections to inclusion of Hamley's meta-analysis in this wikipedia article on saturated fat are without merit. Hamley is more careful in his meta-analysis than other authors, he adheres to PRISMA & he reaches conclusions that are important and relevant here. Hamley's work is a high-quality secondary source. Inclusion of Hamley's work would improve this article. sbelknap (talk) 12:26, 11 September 2023 (UTC)

The title of this discussion is „no link between SFA and CVD“. Both studies you brought up do not deal with this question but with the question if SFA should be replaced with primarily omega 6. That is a different discussion. Do you have any study that actually deals with the question at hand and supports that there is no link between SFA and CVD? If not this discussion can be closed. CarlFromVienna (talk) 15:30, 11 September 2023 (UTC)

Have you read these studies? They compare a control diet to a diet that substitutes PUFA for SatFat. The PUFA diet was high in ω-6 fat and was not pure ω-6 fat. Thus, the intervention diet reflects standard diet recommendations at the time these studies were done. It is still routine to prescribe a PUFA diet high in ω-6. That is what happens when one eats grains, legumes, and many other plant-based foods as these foods contain PUFAs high in ω-6 fats.

A reduction in satfat *requires* an increase in some other macronutrient: carbohydrate, fat, or protein. For purposes of this line of inquiry, protein & carbohydrate is kept reasonably constant, it is the fat component of diet that is manipulated. To maintain constant total fat intake, some type of dietary fat is increased and someother type of dietary fat is decreased. It is not possible to satisfy your demand for a study that *only* manipulates satfat. That's not a thing.

I propose including discussion of Hamley's meta-analysis in this wikipedia article on saturated fat. sbelknap (talk) 18:15, 11 September 2023 (UTC)

Hamley's criteria for "adequately-controlled" and "inadequately-controlled" is indeed subjective. He just made up reasons to exclude certain trials as "inadequate", when such trials were actually reliable. For example he put the LAVAT trial (Los Angeles Veterans Administration Trial) [18] on the "inadequately-controlled" list based on his bizarre reason that there was insufficient vitamin E intake in the control group. The trial is one of the most rigorously controlled trials performed on the subject (they commissioned food companies to design foods to keep the subjects blinded). It's well known that vegetable oils contain higher vitamin E than animal foods so subjects consuming vegetables oils are going to have higher Vitamin E levels. There is no way round this. It's ridiculous to exclude the trial for this reason. He has other stupid reasons for dismissing other trials.

Steven Hamley is a conspiracy theorist who delivered his paper at the Low Carb Down Under event. He spends a lot of time attacking the American Medical Association. I doubt you are going to gain a consensus here by getting other users to agree with you. I am not convinced by Hamley's methods. This is not the place to promote fringe science. He is not a reliable medical source. You should also disclose here that you have had interaction with Steven Hamley which is an obvious conflict of interest. Psychologist Guy (talk) 20:25, 11 September 2023 (UTC)

The criterion for defining adequacy of control used by Hamley is objective and adequately described in the methods section of his meta-analysis. The lack of sufficient vitamin E constitutes an instance of a "substantial dietary or non-dietary difference between the experimental and control groups that were not related to SFA or mostly n-6 PUFA intake." Assuring adequacy of all essential nutrients in the control group is essential to excluding deficiency of a nutrient as a confounding variable. The scientists who designed LAVAT erred in this way. Excluding LAVAT from his meta-analysis meets his objective exclusion criteria for an adequately-controlled trial. Hamley was not the first one to critique the excluded trials for these design flaws. Many of these critiques were made by others.

Your ad hominem ("conspiracy theorist", "fringe science") against Hamley is hard to take seriously. Hamley gives enough detail in his paper that any competent meta-researcher could duplicate his results.

I don't know Hamley, never met him. I've never had any private exchange with Hamley. I don't recall any public exchange on twitter with Hamley. As Twitter (now X) is a public forum, this is possible, of course. Regardless, this does not constitute a COI. I have no other COI.

As you fellas are anons, there is no way to independently assess your COIs.

Regardless, my proposal stands. So far, the objections raised to inclusion of Hamley in this wikipedia article range from specious to laughable. I've countered each one fully. Enough of this. Lets craft some text on the Hamley article to put in the article. sbelknap (talk) 20:53, 11 September 2023 (UTC)

The criteria Hamley uses is laughable, nobody else would use criteria like this. The LAVAT trial involved commissioning food companies to create entirely new products with vegetable oils in them to keep subjects entirely blinded. This isn't a design flaw. Show me another trial that went this far, the methodology and control was top notch. That trial is one of the most well controlled that we have on this subject. If vegetable oil is going to be used in a trial, the Vitamin E content will always be higher than that of an animal-based diet. I don't know how you would get round this, you would have to invent and alter a vegetable oil which would be very hard to do, almost impossible. If you want to believe Hamley is an objective researcher that is up to you, but it is obvious he isn't. This is very much WP:Fringe. He never published a Meta-regression. The Hooper 2020 meta-analysis includes a meta-regression and is does not employ outrageous criteria [19]. It is a much more reliable source. Nobody outside of the low-carb community takes Hamley seriously. We shouldn't be promoting him on Wikipedia. Psychologist Guy (talk) 21:21, 11 September 2023 (UTC)

To be sure, a near order-of-magnitude difference in dietary vitamin E in LAVAT is no small thing! FTFA:

Vitamin E: in LAVAT, α-tocopherol intake in the con- trol group was 9.4-fold lower than the experimental group (22.6 mg vs. 2.4 mg) [48] and only 16.0% of the current RDA (15 mg) [49]. Based on the average energy intake of the control group reported in the vitamin E paper (2400 kcal) [48] and the estimated energy intake (3150 kcal) and vitamin E (11.54 mg of α-tocopherol equivalents) per capita in the United States food supply between 1959–1968 [50], the vitamin E intake of the control group would be expected to be about 8.79 mg of α-tocopherol equivalents. This was not discussed by any of the meta-analyses.

sbelknap (talk) 21:11, 11 September 2023 (UTC)

And how do you suggest that could be modified? Vegetable oils are higher in Vitamin E than animal fats. Of course a diet high in animal fat will be lower in Vitamin E. This isn't a control issue. There is no way round this. It's ridiculous for this reason alone for Hamley to discount the trial as "inadequate". It is not a valid reason. I have read a lot of meta-analyses and I have never seen any nutritional researcher dismiss a trial as "inadequate" based on the reason cited here. The Hooper meta-analysis is a much better source. Psychologist Guy (talk) 21:44, 11 September 2023 (UTC)

Seriously?

The issue isn't that the PUFA diet had more Vitamin E. Instead, it is that the control diet was *deficient* in vitamin E at 16% of the RDA. Thus, the effect of vitamin E deficiency serves as a confounder. Vitamin E deficiency is relevant to the effect variable, as glycemia drives atherosclerosis. The deficiency of vitamin E in the control group is a serious design flaw. nutritionj.biomedcentral.com/articles/10.1186/s12937-023-00840-1

Hamley was correct in excluding LAVAT from his meta-analysis. sbelknap (talk) 22:22, 11 September 2023 (UTC)

It isn't a design flaw. It is just a consequence of a diet being based on animal fats. Like I said, there is no way round this. Any control diet with high amounts of animal fat will be low in vitamin E. This doesn't mean the trial is inadequately controlled. Even if you disagree with this, hopefully you agree that the Hamley meta-analysis does not show anything significant. Take a look at figure 2 [20]. Look where the summary point is for total CHD events for Hamley's adequately controlled trials. The risk ratio is 1.02 with a p value of 0.84. This is non significant. There is a clear noninferiority in the treatment effect. The difference between the diets is non-significant in Hamley's meta-analysis. Psychologist Guy (talk) 00:51, 12 September 2023 (UTC)

The control diet in LAVAT was the domiciliary diet at the Los Angeles Veterans Administration Center. This was not a diet "based on animal fats" — the domiciliary diet at that time was only 40% total fat, as described in the primary source articles.

The adequately-controlled trials showed that the PUFA-enriched diet did not reduce CHD events compared to placebo. That is the point. This is why citing Hamley would improve this wikipedia article. sbelknap (talk) 02:13, 12 September 2023 (UTC)

As all major nutritional societies recommend swapping SFA for PUFAs, can you point to one that has reflected Hamley in their research? If not, Hamley is only a primary source with no impact. Why then would we allow him to make an impact here if he cannot even make one in nutritional science? CarlFromVienna (talk) 06:18, 12 September 2023 (UTC)

Here on wikipedia, we are to rely on high-quality secondary sources.

Hamley is a high-quality secondary source. It has > 150 citations in the peer-reviewed literature.

According to the two United States National Academies of Science review, the Dietary Guidelines for Americans are not evidence-based.

In its most recent iteration, the Dietary Guidelines for Americans no longer presents the conclusion that saturated fat is harmful. There is a diversity of views and this article would be improved if it reflected that.

The current version of this article gives the position of the nutritional societies. It does not reflect the state of the relevant scientific literature, including Hamley. Lets fix that. sbelknap (talk) 14:34, 12 September 2023 (UTC)

Most recent Dietary Guidelines for Americans [21] says "Chapter 1 explains the importance of limiting intakes of saturated fat to support healthy dietary patterns. Staying within saturated fat limits and replacing saturated fat with unsaturated fat is of particular importance during the adult life stage" (page 102), also "For those 2 years and older, intake of saturated fat should be limited to less than 10 percent of calories per day by replacing them with unsaturated fats, particularly polyunsaturated fats." (page 44). Guideline 4 is to "Limit foods and beverages higher in added sugars, saturated fat, and sodium, and limit alcoholic beverages". Your claim that "the Dietary Guidelines for Americans no longer presents the conclusion that saturated fat is harmful", is odd because they are telling people to limit saturated fat to support health. You dislike scientific consensus I get that but this isn't the place to challenge medical consensus. These sorts of discussions are not productive (a vote may be better). The Hamley source is unlikely to be included on the article because it is unreliable. Psychologist Guy (talk) 15:55, 12 September 2023 (UTC)

Going over the history of this topic, the Hamley source has been mentioned before on Wikipedia in two places. The consensus was to not include it as it is unreliable. I have raised this issue at WikiProject Medicine to gain a new consensus. Hopefully there will be input from other editors so this can finally be resolved. Psychologist Guy (talk) 17:01, 12 September 2023 (UTC)

The way wikipedia works is that engaged editors decide how to proceed.

Now that I've addressed every objection that has been raised here among engaged editors, lets craft some text and add it to the saturated fat article.

Unless there is some other objection? sbelknap (talk) 18:15, 12 September 2023 (UTC)

I am puzzled by the claim that the Hamley article is unreliable. No engaged editor has presented any plausible reason why they hold this opinion. Each objection raised has been shown to be wrong. What is going on here?

AFAIK, this is the best meta-analysis that has been done so far on substituting PUFA for satfat. sbelknap (talk) 20:11, 12 September 2023 (UTC)

These are the recommendations, not the conclusions of the analysis of satfat in DGA. In previous revisions, DGAAC ignored high-quality data and concluded that satfat was harmful. This has been removed from the 2020 DGAs. sbelknap (talk) 03:51, 13 September 2023 (UTC)

Hamley is a paleo low-carber who, at the time he wrote his paper, wasn't even a PhD. His paper doesn't have co-authors. He is a single voice following a fad diet. Weighting this in the article against international nutritional societies would be false balance. CarlFromVienna (talk) 09:31, 13 September 2023 (UTC)

Unfortunately he has also been taking his information about the Dietary Guidelines for Americans from Gary Taubes, Nina Teicholz, James DiNicolantonio etc who are all well noted for conspiracy theories about nutrition. Add Hamley into the bag. The outcome is nutritional misinformation from the low-carb diet crowd. Psychologist Guy (talk) 21:26, 13 September 2023 (UTC)

Whatever the merits of these ad hominem attacks on Hamley, they are original research presented by engaged wikipedia editors. This oft-cited meta-analysis in a quality peer-reviewed journal stands on its own merits. A wikipedia article is improved when important minority POV is included. It seems relevant that there were lengthy delays in publication of the research results of several of the RCTs. The current wikipedia satfat article omits mention of secondary sources that present a POV that *differs* from the current draft of the satfat wikipedia article.

I propose that we proceed with crafting text covering the matters raised by Hamley. sbelknap (talk) 11:28, 14 September 2023 (UTC)