6

votes

Shifting From Saturated To Polyunsaturated Fat Linked To Lower Heart Disease Risk

Answered on September 12, 2014
Created March 23, 2010 at 3:54 PM

I seem to be constantly under fire by a throng of vegetarian/vegan acquaintances who think my lifestyle is wrong wrong wrong. I can usually defend myself fairly intelligently, but I'm not exactly sure what to make of their most recent round of ammo:

http://www.medicalnewstoday.com/articles/183129.php

Any takers? Thoughts? Opinions?

0d2dec01a5ed9363a9915e111ae13f7e

(4583)

on March 24, 2010
at 03:02 PM

Stephans post is up regarding this: http://wholehealthsource.blogspot.com/2010/03/leave-your-brain-at-door.html and he explains it much as I'd expected. I am glad that I now see through these mainstream reports and dig deeper to see the truth. Thanks to a couple years of reading Dr Eades, Peter D at Hyperlipid, Stephan at Whole Health Source, Gary Taubes etc, I have a pretty good BUNK-Science meter.

Eae21abfabb19c4617b2630386994fd9

on March 24, 2010
at 06:14 AM

Stephen wrote up a critique: http://wholehealthsource.blogspot.com/2010/03/leave-your-brain-at-door.html This is the harshest conclusion I have ever seen him write: This paper is a breathtaking example of how far a person will go to confirm his own pre-existing ideas. I can't imagine this kind of paper in any field other than diet-health science.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 10:44 PM

Given that you have to find some balance between 3 and 6, you have two choices. You can limit omega 6 PUFAs or you can take 10 grams or more of fish oil. The later is (a) gross, (b) unnatural, and (c) not generally accepted as safe. I think the better route is to drastically limit n-6 PUFAs. I avoid vegetable oils, pork fat, poultry fat, farmed fish, non-omega 3 eggs, olive oil, avocados, nuts, and seeds.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 10:43 PM

Given that choice you have to find some balance, you have two choices. You can limit omega 6 PUFAs or you can take 10 grams or more of fish oil. The later is (a) gross, (b) unnatural, and (c) not generally accepted as safe. I think the better route is to drastically limit n-6 PUFAs. I avoid vegetable oils, pork fat, poultry fat, farmed fish, non-omega 3 eggs, olive oil, avocados, nuts, and seeds.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 10:42 PM

I agree -- many of the controlled studies are deeply flawed. If that were not the case, I wouldn't advocate against PUFAs, as I do. The Finnish trial, in particular, was really badly done. I trust the Lyon Diet Heart Study much more. In fact, it is the strenth of the Lyon Diet Heart Study and the various studies on "primitive peoples" -- the Inuit, the Kitavans, the Masai, the Tokelauns, the Kuna, etc -- that gives me confidence that omega 3/6 balance is produces dramatic results.

Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 10:28 PM

They had to use the uncontrolled Finnish mental hospital to get their meta-effect for "controlled" studies. I think you will find that is the case with all the reviews coming to the strong conclusion to replace saturate with PUFA. If the evidence were really that strong, it would have been shown in controlled studies by now considering all the effort and millions (billions I think) of dollars spent trying to demonstrate it.

Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 10:21 PM

Great job backing up your statement with the studies! Somehow just because a new study came out we are supposed to forget about any older ones that contradicted it.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 06:43 PM

They cited the 7 country study, it seems, for historical context. They didn't draw any conclusion from it. I do agree that it is unfortunate. That said, there are other reviews coming the same conclusion. Remember, these are studies of people consuming 10% of their calories form omega 6s and about 0.1% from omega 3s. Evberything changes if you change the inputs. That's why I am very very anti-PUFA.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 06:42 PM

They cited the 7 country study, it seems, for historical context. They didn't draw any conclusion from it. I do agree that it is suspicious. That said, there are other reviews coming the same conclusion. Remember, these are studies of people consuming 10% of their calories form omega 6s and about 0.1% from omega 3s. Evberything changes if you change the inputs. That's why I am very very anti-PUFA.

Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 06:06 PM

In GCBC (which may be the best review of the evidence) Taubes dismantles the PUFA good/saturated bad CVD evidence. It is hard to believe that the review article you linked to is not biased when it starts with the 7 countries study by Keyes and doesn't mention that the study is total BS. Certainly n-3 is beneficial to health- the first explanation that would come to mind of any benefit found from a PUFA study is that the omega ratio was probably improved in the subject.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:52 PM

I am as anti-PUFA as anyone, but there is convincing evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe the results are due to relatively abysmal omega 3 intakes of modern peoples. See my comment below/above. Also, see this meta review on fatty acids and CVD, concluding, like every other meta review of which I am aware, that PUFAs prevent CVD (among the omega 3 deficient): http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:50 PM

I am as anti-PUFA as anyone, but there is convincing evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe the results are due to relatively abysmal omega 3 intakes of modern peoples. See my comment below. Also, see this meta review on fatty acids and CVD, concluding, like every other meta review of which I am aware, that PUFAs prevent CVD (among the omega 3 deficient): http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:50 PM

I am as anti-PUFA as anyone, but there is convincing evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe the results are due to relatively abysmal omega 3 intakes of modern peoples. See my comment below. See this meta review on fatty acids and CVD, concluding, like every other meta review of which I am aware, that PUFAs prevent CVD (among the omega 3 deficient): http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:41 PM

I am as anti-PUFA as anyone, but there is overwhelming evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe that the results are due to the fact that once over a threshold omega 6/omega 3 imbalance stops doing so much harm and more PUFAs start helping CVD risk. see my comment below. See this meta review as well: http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

6426d61a13689f8f651164b10f121d64

(11478)

on March 23, 2010
at 05:35 PM

Hi barnaby. I'm not the one who voted you down, but I would find it helpful if you summarized or explained the link in your answer, rather than just pasting a link. Thanks,

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5 Answers

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5
15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 04:55 PM

For a fixed level of omega 3 intake, once over a certain threshold (about 4% of calories), more omega 6 PUFAs don't significantly increase inflammation, including vascular inflammation.

PUFAs do lower LDL cholesterol, however. The end-result seems to be that more omega 6 PUFAs does reduce heart disease slightly (among people over-consuming omega 6 oils and under-consuming omega 3 oils) when compared to other kinds of fat, including monounsaturated and saturated fats. Both of these other fats, however, likely reduce CVD risk when compared to calories from sugar.

On the other hand, getting PUFA intake balanced between omega 3 and omega 6, seems to produce much more dramatic results (huge reductions in CVD and cancer risk). Since most Americans get about 10% or more of their calories form omega 6 PUFAs, this is much more safely done while limiting omega 6 PUFA consumption rather than taking massive doses of fish oil. See the Lyon Diet Heart Study.

By the way, the reason you are better off reducing total PUFA consumption is because of PUFAs tendency to oxidize. It's unclear whether this damage can be mitigated by consuming polyphenol/antioxidant rich omega 6s (like almonds or walnuts or olive oil or avocados) but I would guess it can be to some extent. Modern vegetable oils are often lacking in proper antioxidants.

I try to limit overall PUFA and sugar intake since I know that saturated fat, monounsaturated fat, and starch are safe and I'm not sure I want to gamble on antioxidants preserving my fats to keep me healthy. I also take a small quantity of fish oil (about 1 gram).

6
5cd18bfcafadc56292971e59f2f1faf6

on March 23, 2010
at 07:56 PM

Well, there is one good thing about this study -- the full text is actually available online for free!

http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1000252

I'll read the full thing later but initial impression is that "meta-analysis" throws off all sorts of alarm bells. They took a bunch of randomized controlled trials (the gold standard for studies) that showed no connection between saturated fat and CVD and then did a meta-analysis to show a connection. Meta-analysis is a useful but potentially dubious method. If you've read GCBC, you know Taubes's negative opinion of meta-analysis. The Wikipedia article on meta-analysis does a good job of summing up the problems:

http://en.wikipedia.org/wiki/Meta-analysis#Weaknesses

In any case, this isn't the first meta-analysis to be done on saturated fat and I'm not sure why your vegetarian/vegan acquaintances would think this one is more valuable than say these two...

A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. - http://www.ajcn.org/cgi/content/abstract/ajcn.2009.27725v1?papetoc

No significant differences in fat intake were noted in six case-control studies of CVD patients and CVD-free controls; and neither total or CHD mortality were lowered in a meta-analysis of nine controlled, randomized dietary trials with substantial reductions of dietary fats, in six trials combined with addition of PUFA. The harmful effect of dietary SFA and the protective effect of dietary PUFA on atherosclerosis and CVD are questioned. - http://www.ncbi.nlm.nih.gov/pubmed/9635993

I guess it's back to the old game of pick the study that supports whatever viewpoint you already have.

The other obvious thing that stands out is that this involved replacing one kind of fat with another kind of fat. In the context of the past research on SF, this study seems to be more about the potential protective quality of PUFA than harm from SF. Maybe getting more PUFA is a good thing but it seems unrealistic that someone could get the bulk of their calories from PUFA so the rest have to come from somewhere else. It seems clear that getting those calories from saturated fat is vastly preferable to getting them from carbs and nothing about this particular meta-analysis suggests otherwise.

Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 10:21 PM

Great job backing up your statement with the studies! Somehow just because a new study came out we are supposed to forget about any older ones that contradicted it.

5
Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 05:13 PM

For starters, this is a review meta-analysis article of RCT data- potentially the highest quality of evidence we can come across. So I am glad to see these kinds of things being cited and used as evidence instead of the usual non-causal evidence. But the problem with review articles and meta-analysis is the bias in applying the inclusion/exclusion criteria. I can almost guarantee they found a way to exclude the studies that showed margarine was killing people. These studies have been gone over in GCBC by Gary Taubes.

The Cochrane Collaboration was specifically setup to provide unbiased review articles, and they have already done these reviews- they never find a protective effect on total mortality

This is the glaringly obvious problem with this article- the "hard endpoint" that was chosen (heart attacks). A much better endpoint is total mortality, and they would have used it if they could have. Do you care if you die of cancer instead of a heart attack?

There may well be other flaws with the studies used- I haven't read past the abstract. Hopefully Dr. Eades or someone else (that is not brainwashed) will review this article more thoroughly.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 06:42 PM

They cited the 7 country study, it seems, for historical context. They didn't draw any conclusion from it. I do agree that it is suspicious. That said, there are other reviews coming the same conclusion. Remember, these are studies of people consuming 10% of their calories form omega 6s and about 0.1% from omega 3s. Evberything changes if you change the inputs. That's why I am very very anti-PUFA.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 10:42 PM

I agree -- many of the controlled studies are deeply flawed. If that were not the case, I wouldn't advocate against PUFAs, as I do. The Finnish trial, in particular, was really badly done. I trust the Lyon Diet Heart Study much more. In fact, it is the strenth of the Lyon Diet Heart Study and the various studies on "primitive peoples" -- the Inuit, the Kitavans, the Masai, the Tokelauns, the Kuna, etc -- that gives me confidence that omega 3/6 balance is produces dramatic results.

Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 10:28 PM

They had to use the uncontrolled Finnish mental hospital to get their meta-effect for "controlled" studies. I think you will find that is the case with all the reviews coming to the strong conclusion to replace saturate with PUFA. If the evidence were really that strong, it would have been shown in controlled studies by now considering all the effort and millions (billions I think) of dollars spent trying to demonstrate it.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:50 PM

I am as anti-PUFA as anyone, but there is convincing evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe the results are due to relatively abysmal omega 3 intakes of modern peoples. See my comment below. See this meta review on fatty acids and CVD, concluding, like every other meta review of which I am aware, that PUFAs prevent CVD (among the omega 3 deficient): http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:52 PM

I am as anti-PUFA as anyone, but there is convincing evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe the results are due to relatively abysmal omega 3 intakes of modern peoples. See my comment below/above. Also, see this meta review on fatty acids and CVD, concluding, like every other meta review of which I am aware, that PUFAs prevent CVD (among the omega 3 deficient): http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:50 PM

I am as anti-PUFA as anyone, but there is convincing evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe the results are due to relatively abysmal omega 3 intakes of modern peoples. See my comment below. Also, see this meta review on fatty acids and CVD, concluding, like every other meta review of which I am aware, that PUFAs prevent CVD (among the omega 3 deficient): http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 10:44 PM

Given that you have to find some balance between 3 and 6, you have two choices. You can limit omega 6 PUFAs or you can take 10 grams or more of fish oil. The later is (a) gross, (b) unnatural, and (c) not generally accepted as safe. I think the better route is to drastically limit n-6 PUFAs. I avoid vegetable oils, pork fat, poultry fat, farmed fish, non-omega 3 eggs, olive oil, avocados, nuts, and seeds.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 05:41 PM

I am as anti-PUFA as anyone, but there is overwhelming evidence that PUFAs lower CVD risk (using any endpoint) when consumed by modern peoples. I believe that the results are due to the fact that once over a threshold omega 6/omega 3 imbalance stops doing so much harm and more PUFAs start helping CVD risk. see my comment below. See this meta review as well: http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowPDF&ArtikelNr=229002&Ausgabe=250361&ProduktNr=223977&filename=229002.pdf

Eae21abfabb19c4617b2630386994fd9

on March 23, 2010
at 06:06 PM

In GCBC (which may be the best review of the evidence) Taubes dismantles the PUFA good/saturated bad CVD evidence. It is hard to believe that the review article you linked to is not biased when it starts with the 7 countries study by Keyes and doesn't mention that the study is total BS. Certainly n-3 is beneficial to health- the first explanation that would come to mind of any benefit found from a PUFA study is that the omega ratio was probably improved in the subject.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 06:43 PM

They cited the 7 country study, it seems, for historical context. They didn't draw any conclusion from it. I do agree that it is unfortunate. That said, there are other reviews coming the same conclusion. Remember, these are studies of people consuming 10% of their calories form omega 6s and about 0.1% from omega 3s. Evberything changes if you change the inputs. That's why I am very very anti-PUFA.

15d23403fb836f2b506f4f3ad2c03356

(1219)

on March 23, 2010
at 10:43 PM

Given that choice you have to find some balance, you have two choices. You can limit omega 6 PUFAs or you can take 10 grams or more of fish oil. The later is (a) gross, (b) unnatural, and (c) not generally accepted as safe. I think the better route is to drastically limit n-6 PUFAs. I avoid vegetable oils, pork fat, poultry fat, farmed fish, non-omega 3 eggs, olive oil, avocados, nuts, and seeds.

4
8e3782b68e033763485472f414f507a5

(2433)

on March 23, 2010
at 09:41 PM

Stephan from WholeHealthSource will be taking this study apart soon in a blog post near you. Here's what he said today:

"OK, this review is total BS. They included the Finnish trial in their analysis, really unbelievable!!

The title of their study says "Meta-Analysis of Randomized Controlled Trials". The Finnish trial was neither randomized, nor blinded, nor controlled!

I'm looking through the data, there are so many problems with this review it's ridiculous. That's probably why it went to PLoS and not NEJM. I may have to post on it."

0d2dec01a5ed9363a9915e111ae13f7e

(4583)

on March 24, 2010
at 03:02 PM

Stephans post is up regarding this: http://wholehealthsource.blogspot.com/2010/03/leave-your-brain-at-door.html and he explains it much as I'd expected. I am glad that I now see through these mainstream reports and dig deeper to see the truth. Thanks to a couple years of reading Dr Eades, Peter D at Hyperlipid, Stephan at Whole Health Source, Gary Taubes etc, I have a pretty good BUNK-Science meter.

6426d61a13689f8f651164b10f121d64

(11478)

on March 23, 2010
at 05:35 PM

Hi barnaby. I'm not the one who voted you down, but I would find it helpful if you summarized or explained the link in your answer, rather than just pasting a link. Thanks,

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