His update was about saturated fat. In the past, I've disagreed with Dr. Cordain on this issue, because I thought he felt that saturated fat contributes to the risk of heart attack (although he never described it as a dominant factor). He has recommended trimming the fat off meats and using canola oil rather than just eating the fat. I don't know if I had misunderstood his stance, or if he's had a change of heart, but his current position seems quite reasonable to me. Here are a few brief quotes:
By examining the amounts of saturated fats in pre-agricultural hominin diets, an evolutionary baseline can be established for the normal range and limits of saturated fats that would have conditioned the human genome. While these diets varied due to geography, climate, etc., there is evidence that all hominin species were omnivorous. Thus, dietary saturated fats would have always been present in hominin diets.And the conclusion:
There is also evidence that the hominin species that eventually led to Homo began to include more animal food in their diet approximately 2.6 million years ago. Clear evidence shows tool usage to butcher and disarticulate carcasses...
This data suggests that the normal dietary intake of saturated fatty acids that conditioned our species genome likely fell between 10 to 15% of total energy, and that values lower than 10% or higher than 15% would have been the exception.
Consequently, population-wide recommendations to lower dietary saturated fats below 10% to reduce the risk of CAD have little or no evolutionary foundation in pre-agricultural Homo sapiens... So we do not need to restrict ourselves to only tuna and turkey breast, avoiding every last gram of saturated fat.AMEN, brother. I'd like to point out that the average American eats about 11% of his calories as saturated fat (down from 13% in the 1970s), on the low side of what Cordain considers normal for Homo sapiens. This is from the NHANES nutrition surveys.
The effect of a food on an animal's health has everything to do with what that animal is adapted to eating. Feeding a rabbit cholesterol gives it high blood cholesterol and atherosclerosis, but you can't give a dog high cholesterol or atherosclerosis by feeding it cholesterol, unless you kill its thyroid first. Feeding studies in Masai men showed that replacing their fatty, cholesterol-rich milk and blood diet with a cholesterol-free refined diet low in saturated fat caused their total cholesterol and body weight to increase rapidly. Adding purified cholesterol to the cholesterol-free diet did not affect their blood cholesterol concentration. Feeding cholesterol-rich eggs also has a negligible effect on blood cholesterol in most people.
I do still have a slight difference of opinion with Cordain on the saturated fat issue. While I think his numbers for pre-agricultural saturated fat intake are reasonable, his range is probably too narrow. Non-agricultural diets are so variable, I would expect the range to be more like 5 to 30% saturated fat. 5% would represent diets low in fat such as certain Australian Aboriginal diets, and 30% would represent the intake of Northern hunter-gatherers relying heavily on ruminants in fall and winter. During this time, ruminants store most of their fat subcutaneously, and their subcutaneous fat is roughly half saturated. Given that such a wide range of saturated fat intakes are part of our species' ecological niche, it follows that saturated fat is unlikely to be an important determinant of health in the context of an otherwise healthy lifestyle.
33 comments:
Stephan:
You have a dangling, unclosed tag after the 2nd blockquote that's reducing your font size. Blogger likes to paste formatted text unless you go from 'Compose' to 'Edit HTML' mode.
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I think you're correct that the standard deviation in saturated fat intake is way too high to claim that it lies within some 5 % range and outside of that range is 'exceptional.'
As interesting as hominin diets might be, most European populations unlike Native Americans are descended from 5,000 years worth of herders and have evolved the ability to digest milk in adulthood, which sets them apart from Asian populations.
So the effect of sat fats from milks will be very different in populations who have evolved in that direction that it is on those like the Aborigines who did not.
Don't forget, either, some non Europeans made fatty insects and their grubs a huge part of their diet, too. But by the same token, other populations evolved to live on starchy roots.
There is NO one size fits all diet for humans.
My central issue with Cordain's stance (or at least my understanding of it) is that it involves backward logic: he essentially asserts that anything outside the limits of a paleolithic diet is likely to be unhealthy. This logic is flawed: that a paleolithic diet seems to broadly increase human health does NOT imply that something other than the paleolithic diet is less optimal. The paleo diet might be a good framing device for generating hypotheses, but you usually don't get the same answers by flipping the logical dependence (prob(A|B) generally not equal to prob(B|A)).
Many of the connections between a paleo diet and health have independent supporting evidence, e.g. the metabolic effects of refined carbohydrates. As far as I can tell, no such independent evidence (either as good or bad for health) exists for saturated fat. The Cordain papers I've read have never put forth this evidence either, beyond simple and unconfirmed models connecting SFA and LDL production. If he's come up with something more substantive, I'd like to hear about it.
Cordain is an excellent scientist by and large, but he seems to have blind spot, probably caused by a combination of too narrowly defining "paleolithic diet", overweighting the hypothesis that it is optimal for human health, and errors in logical inference stemming from these.
Jenny, just a bit of a nit, references to "Asian" populations is misleading. Mongols (and many northern Chinese, thanks to Mongol interbreeding) have been consuming dairy for a very long time. Anecdotaly, my wife's entire family (from northern China) are very big milk drinkers, but that's not uncommon where they come from.
Further, the term "Asian" in Europe (especially Britain) usually refers to what Americans call Indians or Central Asians, and they're big dairy consumers as well. Only the very Eastern Asians (southern China, Vietnam, Korea, Japan) have a higher prevalence of lactose intolerance.
I agree with your conclusion though: There is no one-size-fits-all solution.
-----------------
As for Cordain, I still don't like his position. He hasn't retracted his suggestion for using Canola oil as far as I am aware. He also uses assumptions about carcass consumption, rather than evidence from carbon analysis of bones and teeth, to shoehorn in his own preferences: that saturated fat consumption was within a range he pre-approved. He also ignores the evidence of present-day or recent Paleolithic cultures with saturated fat consumption far higher than 15%.
That proves to me that what he's doing isn't science, and therefore all of his conclusions are suspect (including the ones I like).
Stephan,
Before it got taken down because of some hacker and then never brought up, the Drs. Eades had a web site called eatprotien.com. On it someone had posted about the issue of how much fat was eaten in prehistoric times. There was a reference to a study done on the deposits left in a cave, I think it was in northern England. The things I remember are; there were predominately the bones from two species of animals. One was around 200 lbs. the other 500 lbs. The writer pointed out that body fat percentage is nonlinear when plotted against total weight. Larger animals have a higher percentage of fat than smaller ones. This holds for animals today so would be expected to hold for prehistoric ones as well. Thus the hunters of this cave were eating a high percentage of fat, given the size of the animals they were eating.
I have tried in vain to find the study. Maybe you might have better luck. I remember some reference to the sun regarding the cave. But searches for "sun cave" do not yield the desired article. HELP !!! :-)
While acknowledging his contribution to the study of nutrition, I gave up on Cordain a while ago. I agree with the other commenters that his conclusions do not consistently flow from logic and he ignores data that does not fit his models.
Adding to Dave's comment, and has Stephan has pointed out many times, there were many mesolithic populations whose health exceeded that of the Europeans who chronicled them. Perhaps their health was not everyhing it might have been on a purely paleo diet, but it was certainly not causing any "diseases of civilization."
The range of human tolerance for a variety of macronutrient ratios is truly amazing.
Scott W
really enjoy the blog Stephan,
im noticing more citations of your posts on many other low-carb blogs,
thanks for your work.
j
I also subscribe to Cordain's newsletter, and am always interested in what he has to say.
But I think he's tried to mold his diet into a very politically correct version of paleo.
Though he does seem to be backpedaling as of late on the saturated fat issue.
I'm particularity disturbed by his very un-paleo recommendation to eat "unlimited" fruit. Many modern hybridized fruits contain loads of fructose. And as Steve has pointed out, fructose is much more of a problem to human health than starch, or even pure glucose.
Stephan,
Spinocerebellar Ataxia 7, CAG/polyQ repeat mechanism under Dr. Garden? Interesting...
Are you looking at CR,CB, and PV, the calcium buffers found in cerebellar purkinje cells?
I think that cracking open neurodegenerative diseases will have a bright future. ALS is my worst nightmare of a disease. Vitamin D implicated only in MS, Parkinsons, and Alzheimers, never seen anything about the SPA's or ALS. Why not post on neurodegenerative diseases?
Has anyone here seen "Fathead: The Movie" where Tom Naughton goes on a month long saturated fat "binge" (including cheese fried in coconut oil)? His total cholesterol goes down about 20 points and his HDL rises 25 points if I remember correctly. He admits its a small sample size, but nonetheless and predictable result to many of us.
Stephan:
Having more fully considered your comment on my post about the same thing...
http://www.freetheanimal.com/root/2009/04/cordain-again.html
...You may be onto something.
Throughout The Paleo Diet (the book), Cordain uses the "artery clogging saturated fat" bromide. He's not using that any more, and that may be the biggest indication of all that he's trying to back peddle.
I wish he's be more forthcoming, but I guess I'll take what I can get.
I think Coach Jeff's comment is right on the money nail.
Robert,
Thanks. I tried fixing it through HTML but I just mangled it. I eventually managed to fix it by cutting and pasting into a word processor and then back.
Larry,
True. I think bigger animals tend to have a higher percentage of saturated fat too. I don't know what study you're referring to.
Homertobias,
I don't work for Gwenn Garden. I'm not going to say whose lab I work in because I'd rather not make my precise location freely available on the internet at this point. There are too many crazies out there. But I would be happy to tell you whose lab I'm in if you send me a personal e-mail.
I don't post on neurodegenerative diseases very much here for a few reasons. My specialty is in hereditary neuroD, which isn't influenced much by diet/lifestyle as far as I know. This blog is about modifiable risk factors. I also try to write about things that are broadly applicable. I may make a foray into Alzheimer's on the blog someday, but really I suspect the causes are similar to the other diseases of civilization. Most of the research on Alzheimer's is very genetic and molecular, which so far hasn't done much to advance our ability to prevent it. But that's changing, and there is some research that would be worth shining a spotlight on.
I just want to say this.
I am astounded by the level of sophistication exhibited on this blog. I really love the honesty and lack of polarization exhibited here. Way too often scientists polarize to one position or another. If it isn't for money, it's for fame. What we need is an open forum. Stephan, thank you so much for providing us with this. I learn from you all.
@LarryAJ
Have you seen the new post of Dr.Eades? Is that the study you was refering to?
http://www.proteinpower.com/drmike/low-carb-diets/nutrition-and-health-in-agriculturalists-and-hunter-gatherers/
I think people attack Cordain all the time, which is a shame, since he's one of the very few scientists who research primitive diets and who has published lots of scientific papers on it (which have alerted some health authorities to the fact that the typical dietary recommendations are very far from ideal). If it wasn't for Cordain, Eaton and Lindeberg, Paleo Diet would be labeled as Quackery.
Instead, he and his colleagues have managed to show that a number of diseases that very few people linked to diet are in fact related to diet and are absent or rare in H/G (myopia, acne, auto-immune diseases).
Nevertheless, as every human being on this planet, he makes mistakes and when he acknowledges them, he tries to correct them. In that regard, I don't know why there are so many people insulting the guy.
Fotr instance and regarding what Coach Jeff and Richard have said about fruit, here's something from his website:
"In general fresh fruits are healthy, nutritious foods that are good sources of vitamins, minerals, phytochemicals, and fiber. Further, they are instrumental in maintaining a net alkaline-yielding diet. Olives, dates, figs, and grapes were some of the first fruits to be domesticated, and pits from these fruits initially appear in the archeological record about 6,000 years ago in the Near East. However, the common fruits we eat today bear little resemblance to their wild ancestors. Domesticated fruits are almost always larger, sweeter, and contain less fiber than their wild counterparts. Compare a Golden Delicious apple to a crab apple and you begin to get the picture".
"...if you are very much overweight or are insulin resistant, I recommend that you initially limit high sugar fruits (grapes, bananas, mangos, sweet cherries, apples, pineapples, pears and kiwi fruit) from your diet until your weight starts to normalize and your health improves. Try to include more vegetables in lieu of the high-sugar fruit. As per my previous recommendations, dried fruits contain excessive sugar, and from the Table below, you can see they more closely resemble commercial candy than their fresh counterparts. Note that some fruits (avocados, lemons, and limes) are very low in total sugar and should not be restricted.
For insulin-resistant subjects, fructose consumption may be particularly problematic. Consequently, I have tabulated the total metabolic fructose for items in the Table below. Metabolic fructose = (fructose + sucrose). In the gut, table sugar (sucrose) is split into its two component parts (fructose and glucose) before it enters the bloodstream. Hence sucrose's contribution to the total dietary fructose load must be considered".
He even has a table with the fructose content of fruit:
http://www.thepaleodiet.com/nutritional_tools/fruits_table.html
Regarding Jenny's comment, it is true that there is no one diet fits all, but instead there are common dietary characteristics to every primitive population that hasn't adopted agriculture and that is what Cordain and his colleagues try to say.
Here's something from one of his recent papers (http://www.thepaleodiet.com/articles/Origins%20Paper%20Final.pdf ):
"Similar to historically studied hunter-gatherers (20, 21), there would have been no single universal diet consumed by all extinct hominin species. Rather, diets would have varied by geographic locale, climate, and specific ecologic niche. However, there are universal characteristics of pre-agricultural hominin diets that are useful in understanding how the current Western diet may predispose modern populations to chronic disease. Increasingly, clinical trials and interventions that use dietary treatments with nutritional characteristics similar to those found in preindustrial and preagricultural diets have confirmed the beneficial health consequences predicted by the template of evolutionary discordance theory"
Regarding the comment that Paleolithic diets are not useful to determine contemporary needs, because there were genetic changes since the neolithic, here's something a good friend of mine who writes for Cordain's newsletter has said:
Exercise, sleep, sun exposure and dietary needs of every living organism are genetically determined, which is why it is being increasingly recognized that the profound changes in diet and lifestyle that occurred in the last 10,000 years are too recent, in an evolutionary time scale, for the human genome to have adapted1-19
In fact, although there were some genetic changes since the Agriculture Revolution20-26, like an increase in the number of copies of the gene AMY1, which codes for salivary amylase27 (the enzyme responsible for starch digestion in humans), various hemoglobinopathies28, Adult Lactase Persistence - ALP28-33 (which affects about 25% of the human population28) and other polymorphisms that can affect certain dietary needs (like the polymorphism MTHFR 677CC27, which affects folic acid status34, mutations in the gene HFE, that may lead to hemochromatosis [iron overload]35, 36, deficiency in the enzyme glucose-6-phosphate dehydrogenase [G6FD], which could make fava beans a potential toxic food37, etc.), most of the human genome is compressed by genes selected during the Paleolithic4, 5, 7, 9, 19, 28 in Africa38-52.
In fact, anthropologic and genetic studies suggest that all human beings living in Europe, Asia, Oceania and America share a common African origin38-52, in a population of Homo Sapiens of ~1,000 individuals49, that would have emigrated for Eurasia ~56,000 years ago49, which is further backed up from the fact that there is less genetic diversity as we move away from Africa45, 50, 53-57.
Furthermore, most of these post-agriculture genetic alterations didn’t occur due to changes in diet, exercise and sleep, but due to pathogens, diseases and a harsh environment30 and their goal isn’t to increase longevity and resistance to chronic degenerative diseases58, but to increase survival and reproductive success, even if they represent a liability in the post-reproductive years4, 19, 58, 59.
For instance, it has been proposed by Cordain, Hickey and Kim that ALP may have resulted from Malaria in sub-Saharan Africans and rickets in Northern Europeans60. Moreover, the same researchers proposed that the MTHFR 677CC polymorphism34 (affecting the needs for Folic Acid) was due to the extreme dermal depigmentation (which leads to a greater photolysis – destruction - of folic acid) that occurred in Northern Europe (together with ALP) to face the reduced Ultraviolet radiation in this extreme latitude.
Also, it is believed that the HFE gene wasn’t selected because of a diet deficient in iron, but to enhance survival to infectious diseases61. And regarding G6FD deficiency, the environmental selective pressure may have been malaria62-64.
It should also be mentioned that, contrary to what has been said in the popular book65 “Eat right for your Type”, Blood Groups A, B and AB didn’t appear after the Neolithic, due to novel dietary lectins, and instead 4,5 to 6 million years66, due to infectious agents67, 68.
Finally, single gene mutations (like the ones mentioned), although important for health practitioners when treating a patient, are imperfect models to prevent chronic degenerative diseases (cardiovascular disease, Cancer, Metabolic Syndrome, etc.) whose clinical symptoms normally affect the post-reproductive years and involve hundreds of genes58, which explains why hunter-gatherers and other populations minimally affected by modern habits exhibit superior health markers, body composition and physical fitness than populations in industrialized countries, but when these populations adopt the western lifestyle their risk for chronic degenerative diseases is similar or even superior to modern populations28, 69-91, reverting (in some cases) when they return to their original primitive lifestyle92, 93.
This clearly shows that there aren’t genetic adaptations that protect us from the modern lifestyle, since our genome best suits the primitive environment, where our ancestors lived.
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Regarding saturated fat and the comment by Brock, he initially talked about less than 10%, but after doing calculations (which could be wrong - I don't know, since I haven't seen anyone else doing these calculations), he found out that the range was 4 to 18%. As for not including Paleolithic cultires who ate more than 15% saturated fat, he does mention them, but stated that values lower than 10% or higher than 15% would have been the exception.
In that regard, I agree, since the research I've conuslted suggests that most of our genome was shaped in Africa, which means that Inuit and other far North populations are not representative of our ancestors.
Brock also makes other assumptions (He also uses assumptions about carcass consumption, rather than evidence from carbon analysis of bones and teeth, to shoehorn in his own preferences"), but doesn't back up what he says with scientific references, so it is hard to either agree or disagree with him on that subject.
My view is: Cordain, as any scientist is working (most of the time alone) as best as he can, but doesn't have all the answers and sometimes makes assumptions that turn out to be false.
I'm a PhD student and I see this all the time. Perhaps, we should all just study, never revele anything, never make any ssumption and just wait until we have definitive proof to tell it to world. If everybody would that, then Medline would have very few papers, since science is allways evolving and there isn't an absolute truth.
Miguel
Homertobias,
Thanks. Where do you get your knowledge, are you a professional scientist/doctor or do you just read a lot?
JMC,
I agree for the most part. Cordain has done some very valuable things.
Miguel,
Even in Africa, I have a hard time believing our hunter-gatherer ancestors would all have eaten 10-15% saturated fat. What other nutrient was within such a narrow range across diverse cultures living in diverse environments?
"This clearly shows that there aren’t genetic adaptations that protect us from the modern lifestyle, since our genome best suits the primitive environment, where our ancestors lived."
I certainly agree that no population, western or otherwise, is well adapted to a modern western diet. But it does seem (as you and others have noted) that some populations (gene pools?) are especially poorly adapted for a western diet. The Pima Indians that Stephan mentions living on flour, canned foods, etc. seem to suffer even more from this type of diet than, say, Americans as a whole. Samoans I've met who change to a Western diet also seem to suffer greater obesity and diabetes than, say, people of northern European descent.
Conversely, if traditional Pima Indians lived healthily on a diet that included corn, beans, and squash, does that imply that they had adapted to a diet different from the Paleo diet of a million plus years ago?
I'm curious because I want to eat more that meat and leaves. I can give up dairy or grains or legumes. I'm not sure I can give up all three.
One more question: has anyone seen studies showing adverse effects from eating legumes? The Google searches I've tried yield mostly studies showing positive effects from adding beans to one's diet. I think I understand the theory, e.g. lectins bad, starches bad. I've seen studies about soy, but not much information about other beans or peas.
And, finally, I want to add my thanks to Stephan for providing an intelligent, non-polarizing forum. It is a fantastic resource.
Dan,
I do think some people are better suited to the modern diet than others. Some of that may come from partial genetic adaptation that has occurred since the invention of agriculture.
But you can't compare the Pima to the average American. Their diet is significantly worse than the average American. You have to compare them to poor Americans, who have a similar diet. When you do that, their health status makes more sense. They still do seem to be particularly sensitive to modern foods, but even people of European descent get obese and diabetic on that diet.
And by the way, have you read Nutrition and Physical Degeneration, by Weston Price? I think it might have some of the answers you're looking for regarding grains and legumes.
Thanks for the comments and suggestion, Stephan. I just had my library interlibrary loan the Price book for me.
I think I may have read his book as a child, from our local small-town library. I distinctly remember a book that described how children who grow up eating butter had more perfectly formed facial features that those (like me) who grew up on Crisco and margarine.
@JMC,
I agree with you both that Cordain is an excellent scientist and should not be insulted. However, if you're a scientist, you have to drink the whole glass of Kool-aid. Hypotheses are supported by evidence, and if you reason from a hypothesis with weak evidence, you should expect to be challenged. The proper way to respond to that challenge is to present the evidence supporting your hypothesis. Cordain has failed to respond to that challenge on that front with respect to negative health impacts of saturated fat.
I've always found it to be an odd blind spot, because he usually provides mountains of evidence in support of his hypotheses. He chose to beat the anti-saturated fat drum, and for the life of me I can't figure out why (beyond politics), because the whole issue is effectively orthogonal to the essential thrust of his other arguments.
JMC,
Great references. Thanks for providing this excerpt.
I've been in discussions with a number of people who claim that there's no evidence that we haven't adapted. What's interesting about this group is where they think the burden of proof lies.
Then there's another segment that likes to claim that the evidence actually hasn't been provided. This latter group doesn't actually *look* for evidence, they just seek to confirm their own biases while telling the paleo group that *they're* engaging in confirmation bias. While we all may have blind spots, this may speak to the level at which people take evolution seriously.
Thanks for the most informative website on nutrition.
I don't know why saturated fat is considered harmful at all. It is obviously used as fuel in the body. So the excess will be stored as fat in the body, just like glucose.
I think that we should eat the omega6 and omega3 in balance and in very small quantities because they are not used as fuels, and should not count them as calories also. While Saturated and Mono-Saturated fats are used as fuel and should be counted as calories.
Also Kitavans show that carbs are also equivalent to fats if they are able to get converted to glucose fast. I think that is the reason we should stay away from low glycemic food products. Because these will keep the blood sugar high for a very long time. High blood sugar causes damage to arteries and there will be less damage if the condition stays for less time. I don't thing the spikes height matters as much as the duration.
-anand
I have laughed and laughed.
"recommendations to lower dietary saturated fats [...] have little or no evolutionary foundation [...]. So we do not need to restrict ourselves to only tuna and turkey breast, avoiding every last gram of saturated fat."
How about this.
I personally, myself listen to the smart people at Harvard who provide real research showing the harm associated with saturated fats, rather than the anthropological speculations of somebody from Colorado State.
In any way, this anthropological evidence is useless, given not only the time that has passed but also the fact that our predecessors have likely starved for longer periods of time and that their insulin levels were not chronically elevated. Or maybe they used the knife to remove the fat. Rofl. Pure nonsense.
"I have laughed and laughed."
Oh, me too....
tortured-soul-boy,
We breathlessly await your references showing that saturated fat is bad for you. Ones that haven't already been debunked as bad science or outright fraud are best.
Thanks.
Tortured soul,
We've been following Harvard's advice for about four decades now, reducing animal fat dramatically, increasing vegetable fats, increasing whole grains, fruit and vegetables, and what has it gotten us:
increased obesity
increased diabetes
very little change in the incidence of heart attacks
fatty liver
the list goes on
Controlled trials have already thoroughly tested the ideas of the folks at Harvard you're referring to. Reducing saturated fat doesn't reduce total or cardiac mortality. Yet they somehow refuse to acknowledge it. Controlled trials have also tested "paleolithic"-type diets, and shown that they have striking positive effects on weight and metabolism. Harvard 0, Cordain 1.
The strategy of the people who you hold in such high esteem has utterly failed yet they refuse to let go of it.
"I personally, myself listen to the smart people at Harvard who provide real research showing the harm associated with saturated fats, rather than the anthropological speculations of somebody from Colorado State."
In other words, you believe in appeals to "authority" and argumentum ad hominem. Did you know that both are logical fallacies?
Lol. Richard, you crack me up.
@tortured-soul-boy:
Do you have any evidence that the people at Harvard are smart?
Any scientific hypothesis needs evidential support. Smart or not, the Harvard folks have utterly failed to provide such beyond weak correlations.
Hi Stephan! Thank you for writing this wonderful blog! I've been reading it for a while, but never commented so far ... As you see, I also like to browse your archives. :)
I've just read Loren Cordains "Paleo Diet" book again and agree that he tended to be critical about saturated fats back then, but he never recommended to banish it from the diet completely. His argumentation is grounded on his research on the fat composition in wild ruminant animals (caribou, elk, buffalo, etc) that show that overall, those animals are rather lean compared to the grain-fed, farmed animals that you get at the supermarket nowadays (and which contain much higher amounts of SaFAs and bad Omega-6 / Omega-3 ratios), and that bone marrow has quite a high proportion of MUFAs, while other parts like brain, organs, and muscle have a rather even composition of SaFAs, MUFAs, and PUFAs, and subcutal fat is rather high in SaFAs. In addition with fats from plant foods (nuts, avocado, etc, which are high in MUFAs and low in SaFAs), he concludes that MUFAs had the biggest part in consumed fats. In his book, he mentions several times that the goal isn't to exactly replicate the diet of our ancestors, but to make our diet functionally aquivalent. Therefore he recommends the use of oils like canola, flax, and olive, as well as switching them up or blending them together, to get sufficient MUFAs and an Omega-6 to Omega-3 ratio of about 2:1 in total dietary fats.
Another argument his puts that plays a role in cutting off the visible fat from meat, next to avoid *too high* SaFAs amounts, is that many farm-raised animals are often fed antibiotics which accumulate in the fat deposals. This way, he accounts for the fact that not everybody (me included, as I am a graduate student with a limited budget) can't afford to buy just organic meats from grass-fed animals, and makes the Paleo diet applicable for a wider range of people.
I agree that he is a bit too harsh with saturated fats - from his analysis, I'd suggest that SaFAs come as #2 after MUFAs - and tends to accentuate PUFAs a bit too much, but I don't understand and really don't like how negative some people write about his research. And while I don't believe that SaFAs are related to heart disease, I don't agree with the "counter-Cordain-movement" that recommends are high intake of SaFAs either. I've been eating Paleo for more than a year now, and started with a rather Cordain-style Paleo diet (rather high protein, moderate fat with equal amounts of MUFA and SaFA), however, in the recent months, I've switched to moderate protein and rather high fat (mainly saturated fats, especially dairy fats) because I've read a couple of other books on Paleo nutrition that recommended that, and I wanted to try it out. I've also tried the nourishing approach with grains and legumes. I know this is just my personal experience, but I felt the best on the Cordain-style Paleo diet, so I'm going back to that now.
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