Talk:Omega-3 fatty acid/Archive 4

Mayo Clinic
This might be helpful:

http://www.mayoclinic.com/health/fish-oil/NS_patient-fishoil/DSECTION=evidence

— Preceding unsigned comment added by Cowicide (talk • contribs) 06:38, 20 September 2009‎

More sources in food
Prickly pears, radishes and raw broccoli have some according to http://nutritiondata.self.com/facts/fruits-and-fruit-juices/2039/2, if anyone cares to add — Preceding unsigned comment added by 70.177.68.241 (talk • contribs) 03:50, 10 May 2012

Dietary sources
Why is the order of the omega3 table so inconsistent - neither alphabetical nor consistently decreasing???2A02:8108:9640:AC3:9CA8:8B2:AC86:1470 (talk) 14:13, 19 July 2021 (UTC)

The sections Health effects and History are in disagreement
The sections Health effects and History appear to have been written by two disjunct groups or individuals quoting disparate sources. It makes the article unbalanced and difficult to read. Could an unbiased editor/expert align these two sections? Theking2 (talk) 09:51, 28 July 2021 (UTC)

Omega 3 in the brain
@Noobnubcakes

This content was recently removed "the brain being 60% fatty acids, of which 84% is omega-3, and less than 2% omega-6". The reason for removal was "Both saturated and monounsaturated fat is more common than omega-3 in the brain" Yet the Wikipedia article also states "A major structural component of the mammalian brain, DHA is the most abundant omega−3 fatty acid in the brain" and elsewhere on the article "The omega−3 fatty acid DHA, also known as docosahexaenoic acid, is found in high abundance in the human brain." We need to know how much omega-3 is in the brain.

Do we have any reliable sources showing that saturated and monounsaturated fat is "more common" than omega-3 in the brain? It is difficult to find exact figures on omega-3 in the brain but this but these sources claim:


 * "The omega-3 docosahexaenoic acid (DHA) and omega-6 arachidonic acid (AA) are the most abundant polyunsaturated fatty acids in the brain as the healthy brain contains ∼15% DHA, three to four times higher than the amount of DHA in any other tissue, and ∼13% AA".
 * "DHA is the most abundant omega-3 fatty acid in the brain and the retina of the eye, representing about 97% and 93% of all omega-3 fatty acids in the brain and eyes, respectively. DHA is key to the developing brain, accumulating in vast amounts during infant development and during the first few years of life. DHA is a central component of the nervous system and promotes neurological development, particularly with regard to the eyes and to fundamental cognitive function." taken from   Psychologist Guy (talk) 13:34, 3 August 2021 (UTC)

The line "the brain being 60% fatty acids, of which 84% is omega-3, and less than 2% omega-6" that was removed was sourced to this article  which says "Omega-6 fats comprise <2% of the total brain fatty acids and, hence, are considered as non-functional. Whereas saturated and omega-3 fats make up over 84% of the total brain fatty acids — and they are mandatory for proper brain functions and development" and "DHA alone makes up 40% of the total brain fatty acids. In contrast, EPA is about 250–300 times lower than DHA in the brain and plays more important anti-inflammatory roles in other organs." So the human brain is not 84% total omega 3 is is 84% omega 3 + saturated fat. Unfortunately it does not cite the exact figures.

All sources agree that the human brain is about 60% fat but we need to know what fatty acids make this number. What is the total omega-3 and what is the total saturated fat? The edit summary "saturated and monounsaturated fat is more common than omega-3 in the brain" does not appear entirely accurate. Do you have any reliable references showing that saturated fat and monounsaturated fat is more common than omega-3 in the brain? Psychologist Guy (talk) 14:10, 3 August 2021 (UTC)


 * Diets that are high in saturated fats negatively impact brain functions and increase the risk of cardiovascular and neurological diseases Psychologist Guy (talk) 15:17, 3 August 2021 (UTC)
 * We have an article on the human brain but there is no mention of what fatty acids it contains. This review says "The omega-3 polyunsaturated fatty acid content of the brain is extremely high, indicating that these fats are involved in brain physic chemistry, biochemistry, physiology and function; and, consequently, in brain development, in some neuropsychiatric diseases and in the cognitive decline of aging". I cannot find any sources discussing monounsaturated fat in the brain. Psychologist Guy (talk) 16:25, 3 August 2021 (UTC)

Lead
The current lead says "Dietary supplementation with omega−3 fatty acids does not appear to affect the risk of cancer or heart disease", this is sourced to a cancer review from 2006 (the review is not about heart disease). A recent meta-analysis published in 2020 in the Mayo Clinic Proceedings concluded "Supplementation with EPA and DHA is an effective lifestyle strategy for CVD prevention, and the protective effect probably increases with dosage."

The following line in the lead says "Furthermore, fish oil supplement studies have failed to support claims of preventing heart attacks or strokes or any vascular disease outcomes", this sourced to a meta-analysis from 2018 and an older source from 2014. However, a meta-analysis published in 2019 in the Journal of the American Heart Association concluded that "Marine omega‐3 supplementation lowers risk for myocardial infarction, CHD death, total CHD, CVD death, and total CVD". . It seems the lead is citing some outdated information. Psychologist Guy (talk) 00:52, 4 August 2021 (UTC)


 * As for the Mayo Clinic Proceedings:








 * The study in the AHA looks legit but had a narrow focus with rather morbid participants. Participants were ~64 years old, 40% had diabetes and 70% needed to take statins. The risk reduction was 8% for MI, 8% for CHD death and 5% for total CHD. I wonder what the outcome would have been when they had rather eaten healthy. CarlFromVienna (talk) 19:19, 20 February 2022 (UTC)


 * I agree having looked a bit deeper, it is not a stronger source like the others. Based on what all the reviews are saying there is either no effect or a very small effect for fish oil in supplement on many health outcomes. It appears to be quite useless, maybe they even cause more harm than good, I can certainly see why the media and experts picked up on the Cochrane review and reported that it has no effect on heart disease, cancer or strokes, , . Obviously the supplement business is about making money so I can see why you talked about the omega 3 hype but this is only in regard to fish oil supplements. The problem with our Wikipedia article is that we have a section on "health effects" which is mostly on Omega 3 supplements (fish oil) but also contains some studies on omega-3 PUFAS from fish and seafood (I don't think we should be confusing or mixing the two here). There is a big difference between consuming oily fish (salmon) and a supplement. When you look at omega 3 reviews that look at studies on fish consumption they report a lot of positive health outcomes (CVD, stroke etc), not like these fish oil supplement studies. The fish oil supplements seem to have become under heavy fire but all health agencies and governmental groups are recommending people to eat seafood twice a week for omega 3. I think we need to split the article's health effect section so the omega 3 supplement health effects are in one section and not confused with regular omega 3 consumption from foods (even some ALA studies have been mixed in here). Psychologist Guy (talk) 01:01, 21 February 2022 (UTC)


 * , this new review similar to the one already cited in the lead concluded that "Omega-3 supplementation at <2 1 g capsules/day showed no association with CVD outcomes; this seems unlikely to change from future research." It is probably worth citing this on the article as it is a high-quality source. Psychologist Guy (talk) 01:13, 21 February 2022 (UTC)


 * I have skimmed a little through the AHA study. ASCEND, VITAL, AREDS, R&P, ORIGIN, OMEGA, Alpha Omega, SU.FOL.OM did not find any benefits (I looked only at the Conclusion of those studies) while DOIT found "tendency almost reaching statistical significance". GISSI-HF found "a small beneficial advantage". GISSI-P found "an important benefit". (REDUCE-IT also found a benefit but it was not included in the % values I posted above.) So I was wondering how the AHA meta-study could come up with a benefit. Maybe because they also looked at MI? I am not against including the AHA study, but I feel we need someone who better understands what's going on here. CarlFromVienna (talk) 13:20, 22 February 2022 (UTC)
 * Having read through every modern review on this topic in the last 5 years, the evidence seems to indicate that omega-3 supplementation has either no effect or a weak effect on CVD or CVD mortality and either no effect on cancer or an increased prostate cancer risk. No effect on stroke. The positive evidence seems to be limited to cognitive and mental health such as protective effect against cognitive impairment or improving memory function ("mild benefit") or depression in pregnant women which has been cited as moderate to high evidence. There are a few studies which report a protective effect against CVD as moderate or high evidence but they are industry funded by omega 3 supplement companies. My own opinion from looking at many of these reviews and the totality of the evidence is that the supplements are useless for everyday healthy people but might help with certain mental health issues. I have updated the article with some modern reviews but I don't think I will contributing to the article anymore after this. Psychologist Guy (talk) 18:15, 23 February 2022 (UTC)
 * The concern about fish oil supplements increasing risk of prostate cancer has been around for a decade, and supported by this recent review  although we are dealing with what would be considered low evidence, for example the review noted "Increasing total PUFA in 1000 people appears to prevent five people dying from CHD, but two additional people will die from cancer. Sixteen people will be protected from CVD events, nineteen from CHD events, but eight more will be diagnosed with cancer". Which ever way you look at this, these numbers are not very encouraging for these supplements. As a summary on a website I found of these reviews concluded, "Taken together, the results refute the notion that omega-3 [supplementation] is a cure-all. As far as cardiovascular disease and cancer are concerned, it has little influence." ,  Psychologist Guy (talk) 21:59, 23 February 2022 (UTC)
 * I removed a primary study (rat model), we should not be including in vivo studies, they fail MEDRS Psychologist Guy (talk) 22:06, 23 February 2022 (UTC)

Splitting up fish vs supplements
I'll give this an extra headline, because I think it is important for others that watch this page and later on for the archive. The article is about omega 3s and I would not include studies or recommendations about fish in it. Possible positive effects of fish consumption may have a variety of reasons, one being that less read or processed meat is eaten because it is replaced with fish. Studies about fish consumption are usually observational studies, while studies on omega 3 are usually clinical studies and trials. To my knowledge there is no definitive proof that the effects of fish consumption are mainly linked to omega 3. CarlFromVienna (talk) 09:11, 21 February 2022 (UTC)

Food Politics & cognitive decline
Marion Nestle has written about the food politics surrounding omega 3. I think it should be included in the article. Omega 3s (especially DHA + EPA) are not like any other well-understood nutrient. There is a lot of scientific uncertainty and industry interest at play. For the politics around this nutrient I think no MEDRS are needed and Nestle is a reputable source. Here are some links to her blog:

CarlFromVienna (talk) 09:21, 21 February 2022 (UTC)
 * here and
 * here and
 * this broader search (rather time consuming)


 * I read though a bit, she is finding that some of the studies on omega-3 are industry funded (companies selling omega-3 supplements) so the research is obviously biased. That is a valid point but not all studies are. For example this review found that "Evidence from 33 studies suggests that dietary and supplemental LC ω3 PUFAs have a protective effect against cognitive impairment... The protective effects LC ω3 PUFAs on cognitive function and reduced risk of Alzheimer’s disease were supported by both observational studies and RCTs, with RCTs suggesting a more pronounced effect in individuals with early and mild cognitive impairment." The authors were not funded by any omega 3 company, I cannot see any conflict of interest. The authors look well experienced i.e. . I agree that many of the studies probably are funded by the food industry in this area, but not all are. I don't object to mentioning this fact but I think most readers will be aware of this. Psychologist Guy (talk) 17:45, 23 February 2022 (UTC)
 * If I find the time I will add a little form Nestle to the article. The conclusion of the study you mention sounds to me as if the authors jump from observational studies on fish consumption to supplements: "Evidence from observational studies appears promising for prevention of cognitive decline. Regular consumption of LC ω3-PUFA rich foods in healthy populations without pre-existing AD or dementia suggests a protective effect against future AD. Conversely, clinical trials that primarily focus on participants already diagnosed with AD consistently report no effect. The incongruence between these findings highlights the precedence of LC ω3 PUFA intake earlier in life, before cognitive decline is apparent and AD risk has been recognised." So the long-term protective effects of O3 are only a conjecture. What if it's not the O3 in fish but that fish replaces more unhealthy food like processed meat and cheese? This whole field of research is a total mess. CarlFromVienna (talk) 07:20, 24 February 2022 (UTC)