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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« Fats and Oils | Main | PaNu on the cheap »

Fish Oil - or not?

Let's start with some terms. Let's call an artificial or synthesized substance that we consume in addition to food a drug, and a more or less "natural" substance in artificially concentrated amounts a supplement.

It should be obvious by now that I generally don't believe in drugs or supplements. If you are deficient in a substance that you are not getting in your diet or that your body would normally manufacture but doesn't, that is replacement. Examples: a 35 year old woman who is hypothyroid due to autoimmune disease from eating wheat needs to take synthroid; a 42 year old woman has premature menopause from a lifetime of hyperinsulinism and uses hormone replacement therapy; a Naval officer does a three month underwater tour on a nuclear submarine and takes vitamin D to compensate for his deficit of normal Vit D production caused by lack of exposure to UVB from sunlight.

If one eats properly in a manner to which we are adapted, the law of unintended consequences would dictate that introducing extra amounts of any specific substance, whether a "natural" micronutrient, a "vitamin" or a big pharma drug developed in a laboratory, is more likely to do harm than good, the same way randomly adding a part to a piece of carefully designed machinery is more likely to screw it up than improve it.

My reading of the available evidence is that supplementation only is of benefit if you are actually deficient in something. Trials of "excess" antioxidant vitamins have provided zero benefit, for example.

If you are supplementing with fish oil, it is to counteract the excess Omega 6 fatty acids in your diet. Maybe we should call that compensatory supplementation - you are compensating for something screwed up in your diet.

It is far and away preferable just to not eat the excess Omega 6 fatty acids in the standard american diet in the first place. 

Don't cook with seed oils. Corn, canola (rapeseed), peanut, saffllower, cotton, margarine, even olive oil.... are all seed oils.

Don't eat processed or fried foods that contain them. 

If you are eating lots of seed oils, you would have to take quite a lot of fish oil to counteract the effects of the excess O 6s. It may help, but is much closer to the EM2 to just cut out the O-6s in the seed oils.

My advice to take the fish oil was a bit of a throwaway. It is more theoretical than proven, and I don't do it myself as I mostly eat wild game or grass-fed bison and only infrequently eat chicken or pork.

Visit Peter's blog here and read his biochemistry heavy posts for his rationale on this. He points out that the Pork and Chicken may be more of a worry than the beef regarding the fatty acid ratios, but remember that he is in the UK and beef here in the 'states is likely worse as it's more corn fed.

Peter points out that extra O 3 fatty acids may not be healthy if you have high carb consumption, but are probably good on LC and high fat diet.

It is all rather complex. Do you see my point now about randomly "improving" a presicion machine and assuming it will run better?

PaNu assumes the machine will run best on the proper fuel, not that adding a magic ingredient to the gas tank, (like STP in the 1960's) will make it run better!

Possible sources of fish oil include cod liver oil and sardines tinned in olive oil or water. I do eat a few sardines because I like them.

I take no fish oil.

I do take Vitamin D (which is not a vitamin) and think that is way more important than fish oil. I'll post more on that later, but I will be raising my recommended dose on that soon. 

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Reader Comments (14)

kurt, could you expand on olive oil? my impression has been that oil high in mono-unsaturates was good for you and less susceptible to rancidity. is macadamia oil any better? it's just a bit higher in mono-unsaturates, but it's hard for me to believe that it's a significant difference. or are nuts just another variation on seeds? peanuts aren't true nuts, i know, but is nut oil ok? why? and what oils are ok? coconut's a nut; lard is from pigs fed on who-knows-what.

June 20, 2009 | Unregistered Commenterjeff klugman

on another topic raised in your post: supplementation. i think your analogy of adding a part to a machine is misleading. perhaps it's more like adding a random something to a soup- most likely will do nothing, a chance it will help. some chance you'll make it inedible. still, it's hard for me to see how adding some omega-3's, perhaps 2 grams/day, is going to do any harm.

June 20, 2009 | Unregistered Commenterjeff klugman

Hi Jeff

Olive oil is a bit of a politically correct fad. It has it's origins of course in the supposed mediterranean diet - of which there are several, and of which only some had any olive oil in them. The support for olive oil was the general scheme that saturated fat is bad and monunsaturates and PUFAs were the alternative. Even Taubes says MUFA is good, SF is neutral and in general, and mostly due to excess PUFAs in the form of linoleic O-6, PUFAs are bad.

I and I believe Peter would modify this and simpilify by saying saturated is best because it is not oxidizable, MUFA is next and total PUFA shold be as low as possible. O3 PUFA supplements are for people with too much O6 PUFA form seed oils.

Now, it goes without saying that this is the polar opposite of a Furhman or Ornish low fat diet.
It would be impossible to get a lot of your calories from sat fat without animal products.
When you do eat animal products and are low carb, you are getting huge amounts of MUFA from the animal fat - check out the MUFA content in a steak or in butter and it nearly matches the sat fat. Bone marrow is the big evolutionary source of MUFAs, not cold pressed olive oil. Of course there is some oxidation going on when you cook with olive oil that will defeat the purpose, so I eat it cold for flavor, but I get plenty of MUFA without olive oil in my animal based diet.

To your second question, all metaphors are blunt instruments if you are trying to persuade, so point taken. The metaphor is more apt for drugs, I suppose, than supplements. Most MDs would take issue with that too, for obvious professional reasons. But I am sure you see my point.

As far as O3s, I go with the general idea that first all PUFAs should be minimized to get your O6s down and to favor SFAs. It is best to limit O6's to less than 4% of calories - I just calculated mine at 2.75%. If you cannot or will not limit O6,s (vegetarian or vegan diet) then O-3s are required to counteract the O6's. If you are above 4% O6 then supplementing to get to 1% O3 has definite benefit.

I would then apply my blunt machine metaphor to say that artificially reversing the O3 to O6 ratio from the 2:1 ratio we evolved eating by oversupplementing with O3 and cutting O 6 could be just as bad for your metabolism.

I eat sardines occasionally and I eat cod slathered in butter once a week, and I put crab bits on my green salads for flavor - I haven't calculated it but I suppose I am getting plenty of 03s without cod liver oil or fish pills.

If you are following Furhman and getting a lot of seed oils with high O6 levels, you may need more that 2 grams per day.

June 20, 2009 | Unregistered CommenterKGH

thanks for the response, kurt. how about the question about other fats? nut oils?

June 20, 2009 | Unregistered Commenterjeff klugman

Nuts and Nut OIls

The evolutionary principle would suggest that once we think there is benefit to a particular artificial food, like an oil mechanically extracted from a seed or a nut, we should look for evolutionary discordance or concordance - could humans have eaten it in those amounts?

Grains and seed oils - corn, safflower, cotton, peanut, canola, flaxseed (linseed) all fail this test, IMO

How about nuts? I started out a big nut eater, thinking they were healthy and natural. I've found that they are loaded with carbs, though, and they seem to disturb my gut if I eat a lot of them, due to some lectins, no doubt. After research about SFAs and MUFAs and such, I definitely do not view them in some therapeutic, micromanaging the diet way like many bloggers seem to. Indeed, I can't think of any reason at all to eat them except to add flavor and interest to salads and other food -that is how I use them.

Nut Oils? Surely safer and better than grass seed oils - I use walnut oil and olive for flavor sometimes. Any advantage over butter or ghee or grass fed tallow or lard?

In my opinion, no. Too many PUFAs in nut oils to prefer them to butter and animal fats.

June 20, 2009 | Unregistered CommenterKGH

kurt, i don't think "could folks have eaten [oils] in those amounts" is the right question. as you say elsewhere, the goal is not to duplicate the paleolithic diet. i'm not fond enough of grubs to do that, myself. it's to recreate the metabolic milieu. so whether paleolithic people ate something [e.g. milk, e.g. nut oils] doesn't address a food's benefits or harms.

June 21, 2009 | Unregistered Commenterjeff klugman

It is if we start with contemporary evidence that that excess PUFA fatty acids are harmful, per my usual method.

See the new fats and oils post and the new grains post. I believe the method is sound.

June 23, 2009 | Registered CommenterKurt G. Harris MD

Kurt, I like your use of 'replacement' instead of supplement. I am also a supplement skeptic. I threw away my fish oil capsules, the only supplements I was taking, and just have regular mackerel, trout, salmon, sardines or herring instead. Paradoxically, I also started taking Vit D around the same time after a test showed I was defficient, despite the vast amounts of oily fish and eggs and what I thought was enough sun exposure. Look forward to seeing your post about that

KGH - your approach regarding nuts exactly mirrors my own. I recently decided to stamp down on my nut consumption. Whilst I can rely on appetite to enforce moderation with all paleo foods, with nuts it just doesn't work. I binge. To me this tells me something is wrong. I also got stomach issues when I ate too many. I did try roasting them and was going to try soaking (to remove the toxins and mitigate the stomach issues) but the roasting just made them taste even nicer and I ate more. Now I only occasionally have roasted cashews in curries and walnuts in salad. Feel much better as a result and much easier to slim down when required.

Hey Methusalah

I am lucky enough to live on the water close to lake michigan. I have a neighbor who leaves salmon filets on my doorstep caught only hours ago. Now, salmon are not native to lake michigan, but they are stocked young and grow in water that is cold enough to kill you in July, so I guess there is plenty of O- 3 in that fish. It's possible that non- replacement supplements we did not evolve eating a lot of could make you healthier, but it seems as likely that changing the geometry of my exhaust manifold will improve my car's performance beyond what those german engineers could achieve.

RE: Nuts -

I am learning to be suspicious of foods I need to "defend myself from" and favor those that are helpless after I harvest them.
Nuts are like a bowl of peanut M and Ms or potato chips and they give me cramps if I eat them in the amounts they seem to want me to.
Lectins plus carbs feeding my gut flora?


June 25, 2009 | Registered CommenterKurt G. Harris MD

Kurt - great analogy. German engineers vs. amateur mechanics...Of couse the German engineers' work was predicated on the assumption of the correct fuel being used. But since most people are using the wrong fuel, large numbers of self-appointed professional mechanics have reached difference conclusions from the German engineers based on tests with those people; and rather than considering questions about fuel quality they are instead tinkering with various geometries, ultimately leading to decline....


I just clicked on your link. I had not seen your site before! You've got some good stuff there.

As a physician, I like this quote:

"...in the context of a medical profession with an almost willful lack of interest in how diet affects disease, I can't see I have much to lose..."

Sad that most folks are on their own in the area that affects health the most - but maybe that will help empower people, too.


June 26, 2009 | Unregistered CommenterKGH

Thanks Kurt - I agree about the empowerment, a lot of which seems to be happening via the online community.

So is Olive oil OK? If not, what do I make salad dressing out of?

KGH: Sure, olive oil and vinegar is great for salad dressing- olive oil's just not good to cook with

January 6, 2010 | Unregistered CommenterDave, RN

Although I often eat a lot of them (lately), I'm not on board with nuts being that healthful.

Like everyone else here, I find nuts much like crack. Really easy to over-consume and not filling! Generally I try to limit my consumption to a small handful on salads, but sometimes I want to enjoy some of my old favorite Western Diet baked goods. Out comes the almond meal. I figure its much better than giving in adn eating forbidden stuff ;)


I agree - when something reminds us of crack, we should strive to think how else it may be like crack:)

My big problem with nuts is they are usually most available in a form that is old and roasted - how can they not be full of oxidized PUFAs, therefore?

January 6, 2010 | Unregistered CommenterGrok
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