Thursday, January 14, 2010

New Saturated Fat Review Article by Dr. Ronald Krauss

Dr. Ronald Krauss's group has published a review article titled "Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease". As anyone who's familiar with the literature could have predicted (including myself), they found no association whatsoever between saturated fat intake and heart disease or stroke:
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.

75 comments:

Aaron Blaisdell said...

The tide is turning!

Ryan Koch @ Health Matters to Me said...

Awesome! Can't wait until this stuff hits the mainstream and all those prominent nutrition gurus -- like Dr. Oz and Andrew Weil -- are forced to take a good, hard look at the unfounded information they've been swallowing for so long.

Daniel said...

Is it time to invest my savings in coconut oil futures?

http://www.commodityonline.com/commodities/oil-oilseeds/coconutoil.php

caphuff said...

Don't know much about Oz but Andrew Weil looks to be leaning toward the low-carb crowd these days.

http://www.drweil.com/drw/u/ART02945/How-Dr-Weil-Eats.html

Brian said...

WE WIN!

(now pass the bacon)

"Guppy" Honaker said...

Hey there Stephen. First, GREAT blog! Then, I agree, a lipid researcher doing an honest review is pretty astonishing.

Keep up the good work on you blog. - David

Aloe Vera 101
Holistic Health Info.
Healthy Recipes

A said...

So, Frank Hu, one of the coauthors on this study, is basically a close second to Walter Willett in the field of nutritional epidemiology. Both are at Harvard and have been for quite some time. Hu has written one of the seminal books in the field, "Obesity" - again, just second in importance to Willett's bible "Nutritional Epidemiology," which is currently being revised.

I had chance to hear Hu give a lecture recently on the etiology and rise of obesity in the US and elsewhere, and he noted then (and my ears perked up) that he (I paraphrase) is becoming more and more convinced that carbohydrates are the problem, and not the fats. This is significant in that this point of view is still largely heretical, if not among nut.epi. researchers as much anymore, then certainly among the ADA/AHA/AMA/etc. I am excited to find out where nut.epi. will be venturing next...

Final note: it appears that Siri-Tarino (lead author) has another opus coming out in AJCN shortly (see footnote 46). Am curious to see what that will say...

Thanks!

Alyssa said...

This is awesome... i'm trying to figure out an easy way to post to facebook so all the world (ok, 250 people in the world) can see!

I used to work for the AHA... It is a great organization, but SEVERELY misguided.

Elizabeth Walling said...

Well, fry my boots (in lard of course). It's good to see some literature that doesn't point the finger at saturated fat! I just wish more of the experts could be objective - results like this would be popping up everywhere.

Robert Andrew Brown said...

Thanks Stephan and Peter,

Excellent news.

But I think it is important to keep a balanced outlook.

Mitochondrial function is dependent on the fat composition of the membranes.

Too much saturated fat in the membranes outside natural parameters may well have negative functional effects, particularly on electrical function. So excess saturated fat may contribute to for example arrhythmia.

http://molinterv.aspetjournals.org/content/2/7/431.long

FIG 7

Whilst saturated fat intake based on what we might find in true migratory herbivores is OK, they contain a higher proportion of monosaturates than industrial fed animals.

And then there is the issue of Omega 3 and 6




Author Omega Six The Devils Fat

(rewrite on the way with over 2,100 references)

www.Omegasixthedevilsfat.com

Jenny said...

That is amazing. I wonder if anyone will notice. I sometimes think we bloggers are the only people who actually read these studies. Do the people who get paid to be "professionals" who don't laugh at us for taking them seriously. My doctor seems to think it's quaint.

arnoud said...

The abstract of this important and wonderful meta-study provides a pretty clear clue that the researchers are planning to investigate something else of great importance. The last sentence reads:

"More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat."

I expect that this suggested follow-up research will nicely fit some key issues that are frequently addressed in this great blog.

Helen said...

I posted a link to this study on Facebook and it elicited a derisive reply by a friend who has a history of not wanting to hear what I have to say about this. He noted that it was partially funded by The Dairy Council and chose to discount it.

Often I find that the people I know who are most concerned about their "cholesterol" or who actually have CVD are the least receptive to hearing anything but the party line. Even if it comes from the Party.

David said...

uh, I pointed this out in a comment on your last blog post - before peter posted the link, my guess is he got it there.

David said...

The abstract of this important and wonderful meta-study provides a pretty clear clue that the researchers are planning to investigate something else of great importance. The last sentence reads:

"More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat."

I expect that this suggested follow-up research will nicely fit some key issues that are frequently addressed in this great blog.

---------

Actually, if you read the discussion section, they argue that it is likely that replacing saturated fat with polyunsaturated fat is likely to LOWER cardiovascular disease risk, but that this will depend on the level of total fat in the diet.

healthtec said...

This is again a myth proved wrong because saturated fat has always been curtailed from the diet of such patients and even made responsible.

Medical Billing Software

Gabriella Kadar said...

I can't read any of that article except the abstract. How did everyone else around here manage to get more information?

kilton9 said...

Yeah -- sure would be nice if someone could post a link to the whole thing instead of discussing it like everyone has access.

frank said...

Is the full paper available online?

Helen said...

Kilton9 -

It costs money to access it - each time. You can't just post a link to it.

Robert Andrew Brown said...

David said

Thanks David.

I saw it (-: but did not check the name when I said thank you, so did not realise you were not Peter if you see what I mean.

"New meta-analysis showing no association between saturated fat and cardiovascular disease:

http://www.ajcn.org/cgi/rapidpdf/ajcn.2009.27725v1

January 14, 2010 12:26 AM"

thadgauthier said...

Could someone explain what this means:

" The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were 1.07 (95% CI: 0.96, 1.19; P = 0.22) for CHD, 0.81 (95% CI: 0.62, 1.05; P = 0.11) for stroke, and 1.00 (95% CI: 0.89, 1.11; P = 0.95) for CVD"

Daniel said...

Robert Andrew Brown,
Even if a PUFA diet provides superior protection from ischemia/reperfusion injury, it's not a great reason to avoid SFAs (which may prevent MIs in the first place). Also, I think the study only speaks of VFs that occur after ischemia, with the result that the study doesn't suggest SFAs cause arrythmias (outside of in the MI context).

Robert Andrew Brown said...

Hi Daniel,

I am sorry I probably did not make myself clear.

I am not saying avoid saturated fats, just making the point it is all about balance, and the range of fats available in the pre-agricultural diet is likely to determine what the body is designed to function best on.

Omega 6 polyunsaturates in quantity were scare and seasonal in nature.

Mono saturates formed a great proportion of body fat of grass fed animals.

Excess saturates may be an issue too.

leo said...

This is great! I always hear Dr. Krauss and they told me that he really is intelligent!
baby cribs

Sue said...

I emailed Dr Krauss and got a copy of the paper. The email address is listed on the abstract.

phanamere said...

Thadgautier,
You have put your finger on the crux of the findings. I am going to take a stab at translating it into comprehensible language. Relative risk (RR) is a comparison of the occurrence of a selected outcome (like CVD) in groups with specific characteristics such as a group that eats lots of sat. fat compared to another with a contrasting characteristic such as one that eats little sat. fat. The “standard” level of the outcome is set to 1. The risk of the outcome is then calculated as “relative” to the standard risk. So the risk of the outcome is higher than the standard if the relative risk exceeds 1 (such as 1.19, 2.5, 27.4 etc.) The relative risk is lower than the standard if the relative risk is lower than 1 (such as 0.5, 0.02, etc.) When the relative risk is close to 1 (1.1, 0.97) then there is little or no difference in risk of the outcome (CVD) between the comparison groups. What the authors say here is that they compared the most extreme groups (only those consuming the most sat. fat vs only those consuming the least) in order to get the most potential contrast between the outcome of groups. Even though they compared the most “extreme quartiles” of saturated fat intake (only the very most vs only the very least) they only found a relative risk between groups of 1.07 for CHD, 0.81 for stroke, and 1.0 for CVD. There is no wiggle room in these findings for claiming that saturated fat is associated with the risk of CHD, CVD or stroke. The risk of these outcomes is the same no matter how much or how little saturated fat is consumed. Does that help?

Wes said...

The following paper by Cordain et al. looked at the fatty acid composition of wild ruminant (elk, deer, antelope) tissues. While MUFA is dominate in the marrow, SFA is dominate in the adipose tissue, and tended to be higher than either MUFA or PUFA in the brain and muscle tissue. See Figures 1-3 for a summary.

http://www.thepaleodiet.com/articles/Final%20Fatty%20Acid%20PDF.pdf

Robert Andrew Brown said...

Thank you for putting me right there Wes. That is a really useful reference and I had not found it. Michael Crawford mentioned they found high polyunsaturates in cape buffalo.


I will try and re-find the paper that referred to sat fats being higher in grain fed animals.

I am pro unprocessed grass fed animal fats. I have reservations about the effects of grain feeding livestock on the Omega 3:6 profile. I was just trying to say not all "saturated" fat sources are the same, and cellular function says that if you just ate pure saturated fat and nothing else, things are going to seize up sooner or later.

From which it follows that there are likely to be nuances to saturated fat consumption as there are nuances to vegetable fat consumption.

I was trying to avoid this becoming a simple polar argument, for or against "saturated" fats,and so falling into a similar one track rut as the anti-saturated fat argument

The wider argument holds and is better put as; altering the mix of saturated fat, mono-saturated fat, and polyunsaturates in the inner mitochondrial membrane will alter mitochondrial and so cell function.

Diet can significantly alter inner mitochondrial membrane composition.

Altering cell function outside normal parameters will lead to dysfunction.

Thanks again Wes

Robert Andrew Brown said...

I have not seen the full paper, but I presume the paper is looking at western population data.

Western populations in general terms have poor cardiovascular health compared to some non western groups.

So whilst 'saturated' fats are not worse, in terms of cardiac disease for the populations selected, they are not better either, so the question as to why westerners have a higher risk of cardiovascular disease remains unanswered; which brings us back to Omega 3 and 6 etc.

donny said...

Robert Andrew Brown, this study you posted,

http://molinterv.aspetjournals.org/content/2/7/431.long


Adding saturated fat to a reference diet might lower the percentage of calories as essential fatty acids.

"Animals were fed a reference (REF) diet alone or supplemented 12% by weight with tuna fish oil (TFO) (rich in ω3 PUFAs), sunflower seed oil (SSO) (rich in ω6 PUFAs), or sheep perirenal fat (SF) (rich in saturated fatty acids)."

If we take this at face value, adding saturated fat may have "diluted" the essential fatty acids contained in the reference diet.

Perirenal fat is not just rich in saturated fat, it's also relatively poor in omega 3s, at least in grain-fed lambs, compared to adipose.

http://www.cazv.cz/2003/2002/zv2_02/potkanski.pdf

frank said...

@phanamere

very well explained, I've benefits from that too. Thanks!!

Anna said...

I'll have the paper in a few days via the library at the research institute where my husband works.

Helen said...

I got a copy, too, by e-mailing Dr. Krauss (address in abstract). Thanks, Sue, for the idea.

Jack Cameron said...

Robert Andrew brown said

"Mitochondrial function is dependent on the fat composition of the membranes.

Too much saturated fat in the membrane outside the natural parameters may well have negative functional effects, particularly on electrical function. So excess saturated fat may contribute to for example arrhythmia."

http://molinterv.aspetjournals.org/content/2/7/431.long

Figure 7"

After review of your reference and the study on which it is based (pubmed 2764800, by McLennan P L et al, 1989), I find no support whatsoever for your statement that excess intake of saturated fat may result in increased membrane sat fat which may lead to arrhythmia.

On the contrary, this and other studies have found that the saturated fat content of myocardial membranes remains constant at about 32% regardless of saturated fat intake. Rats fed 15% fat, as % of energy, as sheep perirenal fat (high sat fat), olive oil (high mono), sunflower seed oil (high n-6polyunsaturated fat, and fish oil(high n-3 fat) had sat fat intake ranging from 13% to 59% of fatty acids, but all have the same membrane sat fat of 32%. Keep in mind that the body produces saturated fat as needed.

In a subsequent study by the same group (pubmed 84244390: free full text)the rats fed high sat fat and mono diets had 30% mortality, rats fed high n-6 diet had 8% mortality, and rats fed high n-3 fish oil had 0% mortality. The high mortality in the sat fat and mono diets was due to deficiency of omega-3 fats, not due to high sat fat or mono fat.

Apparently n-6 fats do reduce arrhythmia risk somewhat in the absence of n-3 fats, but are not as effect as n-3 fats and greatly increase oxidation of LDL.

So don't hold back on consuming saturated fat out of fear of arrhythmia.

Robert Andrew Brown said...

Jack Cameron,

Thanks for your comments. I will have a look at that study.

The cardiolipin in the inner mitochondrial membrane is remodelled by diet.

http://circ.ahajournals.org/cgi/content/meeting_abstract/116/16_MeetingAbstracts/II_90-b

Robert Andrew Brown said...

Donny

Thank you for that link it was useful.

LeenaS said...

To Robert Andrew Brown:
As for the indigested fats & the lipid membranes in mitocondria and elsewhere in the cells: Most of the calories eaten are used for fuel, not for building. With plenty of natural (animal based) fats in diet the body will have better access to the fatty acids needed for cell walls - and the rest is used as fuel. It can and it will be choosy on what to burn and what to use in cell walls. Besides, SFA's do not interfere with O3/O6 balance, while too much ALA or LA will do that.

On the other hand, saturated fat is perfect for fuel, i.e. calories. It is much safer than say sugary carbohydrates (or plenty of Pufa) outside the cells. And inside the cells, when burned, it produces less leaking electrons (i.e. oxidative damage) in mitochondria than what the glucose does (see Nick Lane). This would explain, why liver turns excess carbohydrates just into palmitine (16 C SFA) in SAD.

Robert Andrew Brown said...

Lena,

Thanks for the thoughts.

Jacks comment kind of sums up the debate

"Don't hold back on the saturates. . . )."

We use the term saturates very loosely. Industrial lard is a source of saturates and processing denudes it of Omega 3s and other nutrients. Living on lard as the sole long term fat source would not be healthy.

My message is the argument is more subtle. If you said it is OK in health terms to eat animal products that have the same saturated, monosaturated and polyunsaturated fat composition as wild grazed animals I would agree with you.

If you said as Stephan points out pacific Islanders do well on fish and coconut I would agree with you.

But I think the unqualified message eat more saturates is just as unhelpful as eat more polyunsaturates.

Saturated animal devoid or low in Omega 3 and high in Omega 6s are not good news.

Yes saturated fats have less influence in the body than the the polyunsaturates, but none the less they influence function, and different saturates have different influences.

Yes saturates are a cleaner mitochondrial fuel.

But an industrial lard diet is going to have negative health consequences.

Again diet does affect the composition of cardiolipin including significant changes in saturated fat content.

I stated above that I am in favour of grass fed unprocessed animal fat sources.

Robert Andrew Brown said...
This comment has been removed by the author.
Robert Andrew Brown said...
This comment has been removed by the author.
Robert Andrew Brown said...

LeenaS

Many thanks for the Nick Lane ref, I have ordered two of his books.

skepticaldoc said...

I just want to make sure everyone knows the conclusions of the Patty W Siri-Taring, IQ Sun, Frank B HI, and Ronald M Krause article. Not as pretty as it has been made out to be. The conclusion was that there is insufficient evidence....."In conclusion, our meta-analysis showed that there is insufficient
evidence from prospective epidemiologic studies to
conclude that dietary saturated fat is associated with an increased
risk of CHD, stroke, or CVD. However, the available data were
not adequate for determining whether there are CHD or stroke
associations with saturated fat in specific age and sex subgroups.
Furthermore, there was insufficient statistical power for this
meta-analysis to assess the effects on CVD risk of replacing
specific amounts of saturated fat with either polyunsaturated fat
or carbohydrate. Finally, nutritional epidemiologic studies provide
only one category of evidence for evaluating the relation of
saturated fat intake to risk for CHD, stroke, and CVD. An overall
assessment requires consideration of results of clinical trials as
well as information regarding the effects of saturated fat on
underlying disease mechanisms, as discussed elsewhere in this
issue (46)."

Can't wait to see reference 46.

Stephan said...

Hi Skepticaldoc,

"Insufficient evidence" is just another way of saying that the diet-heart hypothesis has not been supported by 50 years of prospective studies. You can never prove a null hypothesis, so they could not correctly say "the studies show that saturated fat does not cause CHD". It's just science lingo, it doesn't indicate the strength of their conclusion.

I'm actually glad they put it like that because it's a scientifically rigorous way of speaking. Unfortunately it's not that common in health-nutrition papers.

skepticaldoc said...

Just wondering? Would insufficient evidence to indite mean there is also sufficient evidence to acquit? I don't think so. That would require the clinical trials and disease mechanism research recommended at the end of the conclusion.

Stephan said...

Yes, of course controlled trials are required to determine cause-and-effect relationships. But the point of the meta was to review prospective studies. It was quite clear in that review and others that there isn't a trace of evidence to support the diet-heart hypothesis from the numerous prospective studies conducted over the last 50 years. Have a look at the funnel plot. The larger the study, the more the statistical power, the more likely it was to find a relative risk approximating 1.0.

skepticaldoc said...

These prospective studies were prospective epidemiological studies, not clinical trials. About 1990 the overwhelming epidemiologic evidence supported heart saving benefits of vitamin E. All turned out to be fantasy when the clinical trials were done.

Dr. B G said...

skepticaldoc,

As I am sure you are aware, in food and nature vitamin E never exists as a single isolated entity -- alpha-tocopherol.

Why would studies use a single entity incongruent with food sources?

of course the studies SUCKED. they were poorly designed to start.

Also they used synthetic vitamin E, improperly identified, metabolized and eliminated by our P450 cytochromes.

Have you ever heard of Hippocrates and his quote 'food is thy medicine'... why would the father of medicine say that??!

-G

skepticaldoc said...

My point is that epidemiological studies suck and prove nothing. This meta-analysis provides the average value of several epidemiological studies. The average of several nothings is still nothing. This study provides no new proof or knowledge. And, as I said earlier, insufficient evidence to indite saturated fat does not mean there is sufficient evidence to acquit saturated fat.

Chandler said...

skepticaldoc,

"My point is that epidemiological studies suck and prove nothing."

From what I gather, SFA was only ever indicted based on epidemiological studies. Claiming that it hasn't been exonerated by the same seems to be the scientific equivalent of asking if SFA "has stopped beating his wife yet?"

skepticaldoc said...

I don't believe that SFA has been exonerated by any worthy studies. Some here were making an argument that the Krauss article provided exoneration and I was arguing to the contrary.

caphuff said...

skepticaldoc: "exonerated" from what, exactly?

skepticaldoc said...

They have not been exonerated from contributing to or causing coronary artery disease and atherosclerosis.

caphuff said...

Those bastards, I knew it!

SFAs, I want you all to go and sit down on that bench that says Group W . . .

toddhargrove said...

Skepticaldoc,

Let's assume you are correct that no one has proven that SFAs do not contribute to heart disease. The point still remains that there now remains very little reason to fear SFAs as a source of heart disease. If a person continued to be suspicious of SFAs just because they have not been proven innocent, then by logic they should be suspicious of almost every food on the planet as well.

kilton9 said...

"They have not been exonerated from contributing to or causing coronary artery disease and atherosclerosis."

The sun hasn't been exonerated from contributing to or causing atherosclerosis either. Nor has water. What exactly is your point?

caphuff said...

teh sun and water too?!!?

oh noes!!!

Looks like we is just SURROUNDED by stuff that hasn't been exonerated from contributing to or causing coronary artery disease and atherosclerosis!!!

What's next, air?

I mean, yikes!

skepticaldoc said...

OK. Bon Appetit. http://tinyurl.com/ykg6tg6

You all have it right and Finland has it wrong. Imagine being smarter than a whole country!

Näkemiin

Stephan said...

Haha, you guys are too much.

By the way skepticaldoc, the N Karelia project involved:

-Several diet changes
-Smoking reduction
-Increased risk factor monitoring
-Increased exercise

Also, the CHD death rate was dropping even before the N Karelia project began, according to the paper you cited. Would you explain to us why you're so sure the reduction in CHD deaths was due to a reduction in saturated fat intake?

Stephan said...

Oh yeah, and the N Karelia project also corresponded approximately to the introduction of cholesterol-lowering drugs...

Plus improvements in emergency care of MI patients...

Not a very tightly controlled experiment if I do say so myself!

skepticaldoc said...

It's a crap shoot. Like all of life. If you feel comfortable eating SFA till your heart's content (pun intended), be my guest. I have not seen the evidence showing the safety of SFA and the Krauss meta-analysis article in no way establishes that safety, IMO.
I would bet my life more on the N Karelia project than on this meta-analysis. And, in fact, the SFA eaters are doing just the opposite. Its a crap shoot. The house wins more often because they have the odds in their favor. My intention is to keep the odds in my favor with the best research. Meta-analysis does not qualify. And, I would suggest that readers re-read the authors' conclusions in my original post. It is not a powerful study, IMO.

toddhargrove said...

Skepticaldoc,

I agree it’s a crapshoot. We all have to make decisions based on imperfect information.

Nutritional science tells us little when we look at one or two studies under a microscope. But when we assemble bits and pieces of reliable information from a wide variety of sources, pictures start to emerge from the pixels of info. After reading about nutrition from lots of different angles and perspectives, such as Weston Price on traditional diets, Loren Cordain on HG diets, Richard Wrangham on cooking, and the modern biochem knowledge as assembled and framed by Taubes, Eades, Stephan, Peter, Kurt and others, a picture starts to emerge. The picture shows that natural diets are your best chance to steer clear of disease, and that animal fat is a key part of a natural human diet.

Seeing this picture is really more an art than a science. The root word for science means to cut or split apart. The root word for art mean to join or fit together different pieces skillfully. Stephan, Peter, Kurt and Eades are scientists but also artists who can fit the pieces of info together to make a coherent picture. People like Dean Ornish and T. Colin Campbell cannot make a clear picture of all the info. Their recommended diets don’t fit with what we know about evolution and HG health. It’s bad art. There may be some small pieces of (bad) science to support it that looks good under the microscope, but from a larger perspective that includes evidence from a wide variety of sources, the stories just don’t make any sense. Laypeople are perfectly capable of seeing this. Mainstream nutrition experts can’t because they are lost in the bits and pieces under the microscope.

skepticaldoc said...

Good points, toddhargrove. I don’t disagree. If you look at the studies that were used in the Krauss meta-analysis you will see the same studies that Gary Taubes criticizes in Good Calories, Bad Calories. Taubes mentions specifically: the Nurses Health Study and Walter Willet, Ancel Keys and the Seven Country Study, the Honolulu Heart Study, Framingham and more. These are the same studies that Krauss used for his meta-analysis. The same studies that Taubes found fault with in his book. How can anyone support the meta-analysis and at the same time pay homage to Taubes, who excoriated the studies used to build the meta-analysis? Taubes recognized these studies to be worthless; compiling them in a meta-analysis only compounds their uselessness.

And, I have nothing against lean red meat. My animal protein is almost exclusively fish and venison. The wild deer end up eating a lot of corn out of the cornfields in the Midwest, but fortunately it creates subcutaneous fat which can easily be removed and the muscle doesn’t marble like beef. Venison meatloaf, burgers and roasts can all be very low in SFA. Natural diets do not have to contain excessive amounts of SFA.

Sue said...

Skepticaldoc,
I think no matter what the science shows you are still going to have reservations about SFA. The SFA are bad for you is ingrained in you and you can't shake it.

skepticaldoc said...

Sue, I hold on to my notion because I have not seen good science supporting the healthy nature of saturated fat? I would embrace that science with all my heart.

Stephan said...

I don't think it's necessary to eat a lot of SFA for health. I just haven't found any good reason to avoid it. Every time I look into the claims that SFA are harmful, I find them to be hollow. The hypothesis is a "hangover from the 60s" that doesn't want to die because it's so ingrained in the popular psyche. I can't remember who I stole that quote from.

Plenty of cultures seemed to do fine on diets that were low in SFA. And plenty did fine on diets so high in SFA they'd make a cardiologist's eyes pop out (up to 50% of calories). I will note however that the most nutrient-dense fats are rich in SFA: butter and red palm oil.

Robert Andrew Brown said...

Skepticaldoc


What are you views on Omega 6?

Does your view on short chain saturates eg Lauric acid differ from that on mid length saturates like stearic and palmitate?

What about trans fats as a form of saturate?

frank said...
This comment has been removed by the author.
frank said...

@Robert Andrew Brown

Actually, even stearic acid should be considered as healthy by someone as skepticaldoc since they are hypocholesterolemic

@skepticaldoc

you ask for studies where SFAs are healthy. As far as I know, there is not much, but there is that one

Dietary fats, carbohydrate, and progression of coronary
atherosclerosis in postmenopausal women

SFAs is the only fat (compared to PUFA and MUFAs) in this study that reversed atherosclerosis in post-menauposal women, in the group with the highest intake of SFAs

Now, how many studies do you have that directly show that SFAs worsen atherosclerosis, using a marker like coronary angiography, and not blood lipid markers? None, right?

You ask for proof that they are healthful. I think you are missing the point. We are asking for proof that they are harmful - which really doesn't seem to be the case.

It is important to note that the absence of evidence that they are harmful doesn't make them healthful by default. But it's at least making them neutral.

Now, this is not a call for eating extra amount of SFAs - just not a significant criteria for making dietary choice. Like, avoiding butter because it contains SFAs is not supported by science. It's high AGEs content might be a more important concern - but I haven't review much the litterature on exogenous AGEs and health.

skepticaldoc said...

I don’t have much more to say. This blog started with rave reviews of the Krauss meta-analysis. Comments like: “WE WIN!”, “That is amazing.” and “The abstract of this important and wonderful meta-study…” I didn’t think those comments were accurate so I called into question the real value of the study. Hopefully readers now have a better understanding of the issues and I will now rest. I thank contributors as I too have learned from the discussion. Catch you next time.

TedHutchinson said...

Meta-analysis of prospective cohort studies evaluating the association
of saturated fat

Patty W Siri-Tarino, Qi Sun, Frank B Hu, and Ronald M Krauss

Link goes to a full text PDF thanks to
http://metabolismsociety.org

Robert Andrew Brown said...

Thanks Ted

trinkwasser said...

"They have not been exonerated from contributing to or causing coronary artery disease and atherosclerosis."

"Those bastards, I knew it!"

Hahahaha

IMO it's not too surprising that Ron Krauss was involved, he is a very competent researcher though he badly needs a translator from scientificese to English

http://trinkwasser.wordpress.com/2009/10/30/small-dense-krauss-revisited/

esoecially look back to Peter's posts on Hyperlipid

A couple I think I missed out

http://www.ajcn.org/cgi/content/full/69/3/411

http://www.jci.org/articles/view/6572/version/1

The real revelation was to see Frank Hu "coming out" from the shadow of Walt Willett at last.

I'm similarly optimistic that Simin Liu, who so nearly seems to have grasped things in the past but turned away at the last moment in favour of dogma, will also come onside

t_warri0r said...

The health authorities are fully aware of the serious flaws and omissions in this meta-analysis. This study was funded by the National Dairy Council, dairy being the number one source of saturated fat in the U.S. and many other parts of the world. It was also conveniently published just before the USDA lowered the dietary recommendations of saturated fat for the first time in 20 years, from 10% to 7% of total calories.

Below is a section from the statement released by the European Heart Network in regards to their opinion of this meta-analysis, titled “European Heart Network position piece: Impact of saturated fat on cardiovascular disease obscured by over‐adjustment in recent meta‐analysis”

“However, the meta‐analysis (and an accompanying opinion piece by the same authors (4)) is compromised by a number of serious flaws and omissions.”
“The most serious of these flaws is an over‐adjustment for serum cholesterol levels.”
“Adjustment for serum cholesterol levels will inevitably bias the results of the meta-analyses towards finding no association between dietary saturated fat intake and cardiovascular disease, but the authors do not mention this limitation in their article.”
“As Jeremiah Stamler asserts in his editorial, what was actually found by the meta-analysis was ‘a statistically non-significant relation of SFA [saturated fat] to CHD... independent of other dietary lipids, serum lipids, and other covariates’. A more appropriate and informative analysis would have included non-adjusted associations between saturated fat and cardiovascular disease. An examination of the forest plots provided in the article shows that those cohort studies that did not adjust for serum cholesterol levels were more likely to find a positive association between saturated fat intake and cardiovascular disease, suggesting that a meta-analysis of unadjusted data would likely produce positive results.”

The full statement from the European Heart Network can be found below with references to studies that show a positive relationship between saturated fat and heart disease:
http://www.sydan.fi/lehtiarkisto/sydan_210/artikkelit/fi_FI/elainrasvat/_files/83538765767049682/default/EHN%20position%20piece%20-%20sats%20meta%20analysis.pdf

Below is a published study showing reversal of severe heart disease backed up with angiogram evidence.
http://www.heartattackproof.com/resolving_cade.htm

Matt Murfitt said...

This entire argument against saturated fat started from bad science - one study done in the 60s in the USA concluded that the difference between Japanese and American waistlines was due to one factor only - saturated fat. The grain lobby came in to back that up and gave us the bogus food pyramid we have been using to get fatter for the last 50 years. I have written more about this here:
Not only does it show what I have believed all along, it makes sense. Why would foods that we have always consumed - eg meat - suddenly be found to be the root of all evil?
It never made sense to me. Furthermore, saturated fat is now found to be GOOD for us. I have done a little research and added it on here:
http://www.tony-hakim.com.au/how-bad-is-saturated-fat-really/