Kurt G. Harris MD

PāNu means paleonutrition. The "paleo" here signifies "old" and not necessarily paleolithic. The PāNu approach to nutrition is grounded on clinical medicine and basic sciences disciplined by knowledge of evolutionary biology and paleoanthropology. The best evidence from multiple disciplines supports eating a pastoral (animal-based) diet rather than a grain-based agricultural one, while avoiding what I call the neolithic agents of disease - wheat, excess fructose and excess linoleic acid.

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« Still not born to run | Main | Primal Blueprint »

Sat Fat or PUFA - which one do you fear?

I don't want this blog to be just a blog of commentary on what other bloggers say. The Matt Stone essay was due to repeated queries about his approach, and ended up as a distraction from more important things. Kind of ironic to mention that, as what I am about to write could as well have been written by Matt.

But if someone brings up issues and starts posting links to blogs that are seriously, painfully, at odds with my approach, what should I do?

There are some dangerous ideas out there.

One such idea is that saturated fat is dangerous. That is version 2.0 of Ancel Keys Lipid Hypothesis. (Version 1.0 was that dietary cholesterol was dangerous).

Now what if we take an often helpful idea like low carbohydrate eating and combine it with this dangerous idea?

Maybe we get an even more dangerous idea. An idea like, limiting both carbohydrate and saturated fat simultaneously.

You can only eat so much protein, so a low carb diet is a high fat diet. If we try to eat low carb and limit saturated fat, or animal products, because there is something dangerous about "red meat" or whatever, we are doing something incoherent.

If we are to eat more fats on low carb while limiting animals, guess what?

We have just created a diet that maximizes total PUFA consumption.

Any diet, to the degree it is low carb and says to limit sat fat to only 10%, will necessarily be a HIGH PUFA DIET.

It's simple math.

You have to eat something, and if you are foolish enough to limit carbs in general, and animal fats simultaneously, and even if you eat protein to the point of nausea, guess what's left?

Plant fat.

What predominates in plant fat?

Linoleic acid.

I don't care if you get it all from olive, canola oil and furniture finish (flaxseed oil), you cannot eat low carb and low SFA without eating more than twice as much PUFA as is desirable.

Even if you ate 60% of total calories as olive oil, you are already at about 6% of kcal as PUFA, not counting any fish oil you would need to take to get a reasonable 6:3 balance. This, in my opinion, is more pro-inflammatory and very likely MORE atherogenic than a high carb diet without excess fructose and wheat, and may even result in more hyperglycemia and hyperinsulinemia via leaky gut/liver and hypothalamic inflammation.

You have done this not-so-clever maneuver by replacing carbohydrate, a class of macronutrient that contains two of the neolithic agents (wheat and fructose), with PUFAs, which is a subclass of fat that in excess quantity is a neolithic agent.

I cannot emphasize it enough. Avoidance of excess linoleic acid is far more important than being "low carb".

It may, in fact, be the lead horseman in the post-industrial diet right now.

You can't eat healthy in an evolutionarily concordant manner if you cling to the lipid hypothesis.

SAT FAT or PUFA - only one is a neolithic agent. You already know which one.

Reader Comments (41)

Amen, Dr. Harris. You are my hero.

And this logic you pointed out is exactly why I think Michael Pollan's statement of "eat food | mostly plants | not too much " needs to have a footnote. I'm afraid that his quote makes plant oils seem like they're the best choice.

March 18, 2010 | Unregistered Commenterhomeskillet

GOOD POST!!!!!!! love it- drop the PUFA and eat saturated fat.

what do you think about people trying to "balance" their omega 3:6 with fish oil anyways? i dont see it doing any good if you make a solid attempt to avoid PUFAs/seed&plant oil and use butter, coconut oil, tallow

KGH: If you ate nothing but grass fed ruminants and butter and fish, n-3 supplements are unnecessary.

March 18, 2010 | Unregistered CommenterMALLORY


I agree. I believe Eades once said something along the lines of "Eat food. As much as you won't if its mostly meat."


I believe this is a MAJOR key regarding why my dad has dropped 28lbs so easily. His consumption of vegetable is minimal at best. I made sure he understood right away that adding butter to everything was the way to go. What about putting olive oil on steak before searing or bbqing? Is this alright in your eyes? What would you use instead?


Why olive oil? I don't get cooked olive oil. I'd use coconut or nothing - steak has some pretty good built-in fat as I recall.

Re-read the Type II diabetes and PaNu post - the major change vs prior LC attempts for that man was limiting PUFA,

March 18, 2010 | Unregistered CommenterBen Wheeler

So if I eat omega 3 eggs and bacon every morning would that create a 6:3 ratio issue? Gotta love that bacon.

March 18, 2010 | Unregistered CommenterJacob A.

When you say to avoid Linoleic acid, i assume you arent referring to conjugated linoleic acid, correct?

KGH: Yes, CLA and its precursor vaccenic acid are good.

March 18, 2010 | Unregistered CommenterSal

Interesting timing considering the following. Thanks for clearing up. http://heartscanblog.blogspot.com/

March 18, 2010 | Unregistered CommenterRick chartrand

Why olive oil? I've just always used olive oil for that, far before I new anything about a paleo diet. Just about every marinade uses it, and as you said, just about every chef on the food network looks like they have metabolic syndrome. I will try ditching the oil and just going with salt & pepper. Makes perfect sense.

I've read that post and thats what I was agreeing on in regards to my dad losing weight so easily (elminating PUFA from vegetable oil). Some of the clients at our gym seem to lose it at a much slower rate, and i think the PUFA are the issue here. I give all my new clients the link to the 12 steps, I think I need to do some discussing about the importance of limiting PUFA even more.

Thanks for this post Doc. I've linked to it off my blog for folks to read as I believe it is of great importance. Thanks again.


Thanks for the kind words, Ben.

March 18, 2010 | Unregistered CommenterBen Wheeler

Thanks for this post. Very much appreciated. It can get quite confusing sometimes. I have a moderately high C-reactive protein number. I'm working hard to reduce that inflammation and lose the excess weight doing The Primal Blueprint. The last thing I want is to be sidetracked with backward-thinking info. I'll keep my coconut oil, my ghee, and my heavy cream. Thanks.

March 18, 2010 | Unregistered CommenterSuzan

Great riposte. I gather you're responding to Davis. I actually found his post kind of mind-blowing... he's usually way, way smarter than that. I briefly wondered if his site had been hacked or something. Thanks once more for the good sense.

March 18, 2010 | Unregistered CommenterJohn

Great blog. I noticed that you often refer to leaky gut as one of the problems with the SAD. I haven't seen a post deticated to the subject. Is this related to IBS? I currently have IBS and am hoping to learn more about how going Paleo may help me. I have had good results in the first 3 weeks I have been on the diet. Thanks.

March 18, 2010 | Unregistered CommenterJohn

I totally agree...what is he eating? Leaves? Because everything else is BAD.

BTW, should I be worrying about my PUFA intake from meats like pork or wild boar?

March 18, 2010 | Unregistered CommenterMelissa


Studies show that linolenic acid contributes to IBD. I wouldn't be surprised if it also contributes to IBS, though I haven't seen any specific papers correlating the two. See this article on my blog for more info: http://thehealthyskeptic.org/research-update-carbs-raise-cholesterol-veggie-oil-associated-with-ibs-ibd

March 18, 2010 | Unregistered CommenterChris Kresser

Goodbye low carb flax seed bread, crackers, and yes even the low carb flax brownies. No more candy cigarrettes. Thanks for shoving this information I should have already figured out into my face. I needed that!

March 18, 2010 | Unregistered CommenterAllison

Nutrition is an art, just as complex as any other high-caliber art form.

With that said it is obvious 'paleo diet', or eating the way of cavemen, is NO LONGER the optimal choice. A more realistic option would be in between the sprung of agriculture and this out-dated time frame.

The introduction of agriultural foods sparked a rapid incline in a variety of diseases. Realistically before this, yet after the ape-period, our ancestors thrived on two things: Vegetable-based starches and Wild-caught animals.

Game like elk and buffalo were hunted, and cooked with fire (technology, the obvious demise to your cookie-cutter diet). Foods like plantains, yams, and squash were heated-up as well. What an accomplishment! Being able to use our resources and advancements over the ages.

Only, agriculture has taken technology the wrong way. In the last ten-thousand years, they have completely modified the true structure of 'foods'. Fire was an achievement. Contrastingly, agricultural technology was not. It has merely lead to the demise of proper human nutrition. Diabetes, cancer, and the obesity epidemic are proof!

Once again, nutrition is an art just as complex as any other high-caliber art form. On that note, we cannot conform to scientific-evidence lacking fad-diets.

We MUST throw out what has been PROVEN wrong and continue looking for nutritional truth in humans-- the time period of just over ~14,000 years ago. Before the coming of aforementioned diseases. Before the spawn of agriculture. And much more recent than the MILLIONS of years ago 'paleo diet' was based. Agricultural interruptions must be reversed!

THAT, is when and how our cultures thrived ( :

March 18, 2010 | Unregistered CommenterJEFF

Well,the past is a great place to visit and learn what can but we cant live there.This responce to Dr.Davis's post was timely and necessary,thanks. I have a lot of respect for Dr. Davis and am trying to understand the factors that lead him to those conclusions..How else to explain his conclusions?Behaviour and a high population of meatabolicly challenged people might muddy the water.

KGH: I can't tell you how he comes to his conclusions.

March 18, 2010 | Unregistered CommenterRod

Kurt, do you think its okay to eat low carb with minimal animal fat via lean meats cooked in ghee or coconut oil whilst someone has a lot of adipose fat?


High animal fat (sat and mono predominate) with low total PUFA is the idea. Hence ghee butter and ruminant fat are all good.

coconut is a special case -also good

March 18, 2010 | Unregistered CommenterSue

Is the polyunsaturated fat in eggs (14%, mostly o:6) something to worry about?

I can't really afford grass-fed meats, so I tend to eat grain-fed meat, as well as heavy cream and some cheese. I love eggs, but should I be concerned about them if I'm trying to minimize PUFA?

KGH: Add it up with fitday - there will be your answer.

March 18, 2010 | Unregistered CommenterDavid

I am striving for maximum paleo (not one to go half way). Yesterday I received my 5 gal pail of coconut oil. I like the taste and I enjoy eating it. I plan on making it my primary fat source, like 90%. The remainder is animal fal. No other plant fats.

I have some concerns about animal fats. Bad things tend to accumulate in an amimals fat, plus they're almost 50% Mufa and, if grain fed, too much Pufa. Dr Kurt, do you think this is a rational and healthy fat plan?.

KGH: Maximum paleo? Actually grain fed has the same n-6 just less n-3. Sounds like a pointless amount of coconut.

March 18, 2010 | Unregistered CommenterJames19

Regarding animal fats, read this:

He doesn't include coconut oil, but nevertheless as you can see, butter and beef tallow have more or less ideal fatty acid profiles. Don't worry about the MUFAs in animal fat, they are good.

March 18, 2010 | Unregistered CommenterNathaniel

Ahhh.... the conundrum of what to eat after you eliminate all potentially harmful foodstuff. Perhaps post-panu we shall all become breatharians and live solely on prana.

"Breatharianism believers claim food and possibly water are not necessary, and that humans can be sustained solely by prana (the vital life force in Hinduism), or according to some, by the energy in sunlight." wiki

[Note - Wiley Brooks, founder of the "Breatharian Institute of America" was allegedly observed leaving a Santa Cruz 7-Eleven with a Slurpee, hot dog and Twinkies.] Breatharianistas love the beach life.


March 18, 2010 | Unregistered Commentergymbojim

Thank you!!! I always advise people to avoid all vegetable oils and only use olive for cold use and maybe finishing after removing from heat (scampi comes to mind).

I love coconut oil and use it for everything! I even used it to make brownies for my son and he had no idea!

As for Dr Davis....I thought he was coming around to the advantages of sat fat, but I guess not (sigh).

March 18, 2010 | Unregistered CommenterAlcinda Moore

Great post as always KH. I live in Toronto, Canada, and cannot find a place that sells coconut oil. Any suggestions fellow posters? Thanks in advance. Jim

March 18, 2010 | Unregistered Commenterjim

In response to Jim.

Ambrosia Natural Foods
55 Doncaster Avenue
Thornhill, ON L3T 1L7
(905) 881-7811

Hope i'm not breaking a rule. This isn't spam.

The place sells coconut oil and coconut oil with ghee. Lots of stuff for a paleo person.

March 18, 2010 | Unregistered CommenterRyan

Just google. You can buy anything from Amazon and there are any number of online retailers selling coconut products.

March 18, 2010 | Unregistered CommenterMarnee

You should be able to find it locally in a city as big as Toronto. Here in the states, even Walmart has a highly refined coconut oil. "Natural food" stores usually all carry virgin coconut oil. Don't you have some major natural food stores in Toronto?

If all else fails, you can order some great coconut oil from Tropical Traditions. They have all kinds of awesome other stuff too, including pastured dairy products, pastured poultry, and grass-fed beef, bison, and lamb.

March 18, 2010 | Unregistered CommenterNathaniel

I wish someone would link to the "Matt Stone essay" to which you refer. I would like to know what we are talking about here.

That's the problem with a closed comment list. It tends to make the sites insular and self referential.

Though it's worth it if it allows a busy doctor to be able to blog...

KGH: I want it to be more insular, in fact. It is way too open right now. The Matt Stone post is 180 +180 = 360.

March 19, 2010 | Unregistered CommenterChuck

I am still a bit unclear on olive oil (uncooked). I get SFAs, also, but a big source of fat and veg has been a gazpacho: tomatoes, lettuce, cucumber, paprika, big dose of olive oil, vinegar, salt, & tabasco all whipped in the blender. This has been my fast food until I started reading this blog and switched to tea and heavy cream. Wikipedia lists olive oil as having between 3.5–21.0% Linoleic acid.. I wish I knew where in that bell curve my brand stood.

KGH; Short answer is monunsaturated fat is OK, but saturated fat is better and animal fats have more vitamins. etc.

March 19, 2010 | Unregistered CommenterSean

'PC paleo' is what I call low carb + low SFA.

Dr Davis' last post could cause a layperson such as I more than a moment of confusion. But after eliminating all the undeniably neolithic stuff it's just a case of remembering Peter's 'you need to get calories from somewhere...So, pass me the insuliotropic butter ;-) - I gotta eat something!

March 19, 2010 | Unregistered CommenterTal

Hi, Do you know of any clinical trials in the works for treating dementia, depression or psychosis with a ketogenic diet? There is some help I know for epileptics on a ketogenic diet. Horrifying though is the trend to put them on a high PUFA vegetable fat diet. EGAD. I have an elderly relative with dementia, and I now a mentally ill person and I used to suffer with depression BT (before Taubes). My heart goes out to the mentally ill. They could stay on their meds and eat more sat fat and maybe function better. The dementia suffering relative is getting more fat because I have some control over what she eats.
I think PUFAs, sucrose and grains are a doubly whammy disaster. They cause problems in themselves, but they also REPLACE saturated fat in the diet.
I'm rambling. I've ordered 4 more copies of 'The Vegetarian Myth' and I just got wind of Uffe Ravenskov's new book "Fat and Cholesterol are Good for you". I've ordered 2. I'm giving these out like no-sugar candy.

KGH: Order through my amazon portal if you haven't already

March 19, 2010 | Unregistered CommenterLaurie

Praise the Lord Kurt! When I was predominantly low-carb I made no distinction between fat sources. I did like most low-carbers, and most Weston A. Price Foundation devotees - I rejoiced in eating the chicken with the skin (and practically drinking the fat leftover after roasting), eating tons of fatty pork, and eating as many nuts and seeds as my little heart desired. Mmmm. Walnuts! More LA than soybean oil!

Since cutting back my LA consumption to about 2-3 grams per day, I gotta admit - makes a huge difference. Got the girlfriend off of peanut butter too. She's doing much better.

Anyway Kurt - quite refreshing. In my research it appears that the mass epidemic of "carb intolerance" is a result of the body's counter-inflammatory response with SOCS-3 and cortisol, both known triggers of insuliln and leptin resistance. I'm even of the mindset that it is fully our body's reaction to known inflammatory triggers that is the problem, not the trigger itself, which might include gluten as well (and cigarette smoke, and sunlight, and heavy metals, and well, a lot of things).

I'll also be posting in a few days on what I think really is the most appropriate human evolutionary diet. We are perhaps the most well-adapted mammal on earth for warm, non-seasonal climates. We have little hair. Open pores. We sweat profusely. Stand upright. We don't make vitamin C. Our bodies, unclothed, get uncomfortable below 60 degrees F. In warm climates, the polyunsaturates are almost completely absent from the food chain. We don't even have a biological system to convert or deal with them. They just pile up on our bodies. Omega 3 is even more absurdly appropriate for cold climates (unlike us). A low-PUFA diet is what we were designed for.

Saturated fat is our pal - no wonder our bodies convert carbohydrates to saturated fat.

March 19, 2010 | Unregistered CommenterMatt Stone

"KGH: I want it to be more insular, in fact. It is way too open right now."

Maybe you could let people discuss in a forum that is moderated by other peoples and keep the blog posts without comments. You would not waste as much time and we would still be able to discuss the posts in the forum.


KGH: You still can - the forum is still there

March 19, 2010 | Unregistered CommenterPatrick N.

I think it's because Dr Davis was a vegetarian for a long time, and he still is mostly. He's come a lot farther than most cardiologists though. The fact that he thinks eating too much is a problem on a high animal product diet means he's never even tried it.

March 19, 2010 | Unregistered Commenterzach

Dr Harris,
Thanks for another simple tool with wich to make dietary choices. I can't wait for your beef and coconut posts. Your posts PUFA's and fried foods has me rethinking my chicken and pork consumption. The chicken/pork I eat is almost always conventional and likey giving me too much PUFA.

March 19, 2010 | Unregistered CommenterWarren



pubmed & google are handy

March 19, 2010 | Unregistered Commenterpyker

The case against omega 6 PUFA seems fairly convincing, if mostly circumstantial from what I have been able to find.
Recently the Journal of the American Heart Association published a 7 page article titled "Omega-6 Fatty Acids and Risk for Cardiovascular Disease: A Science Advisory" which basically says eat all the linoleic acid you want, it doesn't seem to cause heart disease.
I'm sure regular readers of this 'blog will not place any more credence in AHA advice than they would ADA advice on eating, but it seems to unnecessarily muddy the waters.

Stephan seems to have collected a lot of good links for research which indicates otherwise, especially corn oil, but it seems that the equivalent of a Taubes GCBC for industrial processed vegetable oils has not been published yet. At least if something of that quality has been published, it doesn't seem to be as widely known.
What is the current go-to for people that are willing to consider the evidence, but are not yet convinced that vegetable PUFA is of any concern?


Stephan for explaining the epidemiology and both he and Peter for relevant animal studies.

The AHA is confused because it is all lipophobic cardiologists and epidemiologists. You can't find epidemiologic variance in diseases due to PUFA on the SAD because EVERYONE eats too much of it.

March 19, 2010 | Unregistered CommenterChris Caudle

I don't know where the nutrition data came from, but This Guardian Article states that in 2004, the Linoleic Acid content of chicken was 2.6 times the 1980 level whereas the DHA content was 0.147 times the 1980 level. It looks like grain-feeding chickens is a double-whammy.


Non- ruminants are much more subject to passing on the ratio they get in their diets. So the unhealthiest beef has a 6:3 ratio as good or better than pastured free range bug-eating chicken, and fowl fat from industrial operations is like eating vegetable oil.

I eat beef, venison, buffalo, lamb and fish. I like barbecued chicken and pork but don't eat them that often.

March 19, 2010 | Unregistered CommenterNige

My most recent dietary/health change was cutting industrial oils from my diet (by recent I mean in the last few months). I didn't really think it was a big deal until I started reading posts on Hyperlipid, and other sites. I tend to eat a lot of beef, pork, and fish, lamb when I can afford it, and only the occasional chicken. I supplement with Cod Liver Oil to attempt to balance out Omega 3's and 6's since I can't afford a diet of all grass fed anything right now.

I deleted Dr. Davis' blog from my blogroll some time ago. I still occasionally take a peek at what he's posting, but by and large would rather anyone who reads my blog not think that I advocate all of his ideologies...thus, he's not on the "favorite blogs list" any longer. This latest post of his wasn't the first one I read where I was shaking my head after reading. Glad you posted about it.

March 19, 2010 | Unregistered CommenterLisa L Crawford

Here is my take on Dr. Davis' quoted study "Distinctive postprandial modulation of β cell function and insulin sensitivity by dietary fats: monounsaturated compared with saturated fatty acids : http://www.ajcn.org/cgi/content/full/88/3/638".

By weight, 35% of a meal was composed of pastas, brown bread and low fat yogurt. Nearly all the carbs were gluten loaded wheat. The rest of a meal was either butter, refined olive oil (ROO), high-palmitic sunflower oil (HPSO) or a mixture of vegetable and fish oils (VEFO) .

The butter/wheat meal resulted in higher insulin, triglycerides and FFAs. BUT this did not happen after eating butter, it happened after eating lots of refined wheat AND lots of butter.

So this would mean that if you are going to eat 60% (by weight) of your meals as butter, you should avoid eating tons of wheat with it. :)



There are many other papers that contradict this one, but even if it is representative, what we are observing is the effect of saturates on serum ffas (and TGs) leading to transient muscle IR, which causes a higher insulin requirement to handle the concomitant carb load. This tells us nothing about whether there is long term effect on liver IR or if the PUFA heavy oils have a negative effect via gut and liver inflammation, etc. It's like the short term studies using FMD as a proxy for atherosclerosis.

And the idea that there is empirical support for butter making you fat is laughable. I get 30% of my total calories most days from pastured butter.

I smiled when I read the post title and thought "what's the catch?" - the catch is he is defining butter as "butter plus carbohydrate". My butter has no doughnuts in it.

March 19, 2010 | Registered CommenterPatrick N

Erin H reports that Peter at hyperlipid has a great piece discussing Dr Davis' referenced study about butter.


March 20, 2010 | Registered CommenterPatrick N

heard a brief of this study- http://www.plosmedicine.org/article/info:doi%2F10.1371%2Fjournal.pmed.1000252#top this morning on npr, and was very disapointed! i briefly read through it, and some online interpretations and it seems very confusing to me. some interpretations i found said that while this analysis finds increasing pufa to be good, other experts, such as yourself warn against pufa. would you please explain this to us briefly?

March 23, 2010 | Registered CommenterEmily C

@emily c
stephan just did a nice little review of that study at wholehealthsource.blogspot.com
in brief- worthless

March 24, 2010 | Registered CommenterJeff Klugman
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