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Thursday, February 21, 2013

The New Paleo Diet Study: Paleo-type-style-ish Diets vs. "Paleo"

There's a new Swedish paleo diet study out: A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women.  The title sounds promising, but my first reaction to it, sadly, not so much about the potential findings, but, what exactly is this paleo-TYPE diet??  It would appear to be based loosely on Cordain's original Paleo Diet (I hear that's trademarked).  

This was a small study, 10 women, no control group, lasting only 5 weeks.  There were some benefits including around 10 lbs average weight loss and almost 50% reduction in liver fat.  This shall be for another blog post.  But what diet was tested?  Here's the diet description from the full text:
Participants were given prepared meal portions that were intended to provide an average intake of about 30 energy percentage (E%) protein, 40 E% fat (mostly unsaturated) and 30 E% carbohydrates for breakfast, lunch and dinner, together with 40 g nuts (walnuts and sweet almonds) on a daily basis for 5 weeks.


All meals were prepared by the food service ... The diet included lean meat, fish, fruit, vegetables (including root vegetables), eggs and nuts. Dairy products, cereals, beans, refined fats and sugar, added salt, bakery products and soft drinks were excluded.   Participants  were instructed to complement the provided food with other included food items from the list, ad libitum. ... They were also advised to use only rapeseed [canola] or olive oil in food preparation. The recommended alcohol intake was less than two glasses of red wine per week.

There are likely a few others, but so far we have Lindeberg, Frasetto and now Ryberg paleo studies.  The nutritional comparisons are shown here.  


The descriptions of Lindeberg's and Ryberg's paleo diets are the same (both Swedish, no surprise!), while Frasetto's is notably higher in carb including more honey and high sugar fruit such as pineapple -- there was more attention paid to potassium content as well.  The Ryberg diet is a bit higher in fat, but at 40% prescribed and 44% (median) actual, it is still rather low in fat compared to what is espoused in various paleo diet books by various advocates.  Indeed two of these diets would qualify as "officially" low fat by the 30% standard, and all three diets are at the sub-10% target set out by the so-called saturated lipophobes.  PUFA contents ranging from 7 to 13% of total dietary intake are quite high and the results in each of these studies must be considered when PUFA is a revived finger pointing target of late.

All of these diets counsel elimination of all dairy.  No Kerrygold popsicles, yogurt smoothies, certainly no sour cream and Philly cream cheese.  No coconut breaded offal parmigiana  or artificially sweetened whey protein peanut butter concoctions from the "ancestral education video" non-profiteer here.  Whether intentional (as in the current study) or not, the saturated fat content of the tested diets beats the so-called "misguided" recommendation of 10% tops, and speaking of coconut, you don't hear any of that!   At the very least, these studies CANNOT be seen as any sort of "vindication" of sat fats or free pass.  Neither are they endorsements for the most popular paleo and paleo-inspired diets.  Having been used by such folks as Nora Gedgaudas and Paul & Shou Ching Jaminet in support of their dietary recommendations, Lindeberg's diet comes in very low fat by comparison.   I've become increasingly disappointed with Paul's recent attempts to score "authentic paleo" points with evermore imaginative claims reconciling PHD with paleo.  We don't know.  It wasn't the same for all paleos.  We couldn't recreate it with modern foods if we wanted to.  We have NO way to know what their true state of health was, and thus if we should even be attempting to emulate their ways. 

Which leaves us where?  I exchanged tweets with Robb Wolf regarding this study.   He seemed no more hopeful that "paleo" would be defined in the clinical trial realm than it is in practice.  Which makes the label all the more confusing and, IMO, ultimately meaningless.  More thoughts to come in my post on the study per se ...  But these studies are increasingly demonstrating that lower-to-low fat relatively higher PUFA diets, per USDA recs, may just not be a problem!  Nobody has as yet denounced any of these studies as not "real" paleo, as the LCers are wont to do when a study doesn't demonstrate the supposed superiority of the low carb diet.



Followup posts on the clinical results of the study:
The New Paleo Diet Study: The Weight Loss
The New Paleo Diet Study: Just the Fats Ma'am

39 comments:

Don Wiss said...

What Cordain has trademarked is "The Paleo Diet." Book titles are not copyrightable, so to keep others from putting the same title on their books, he trademarked it. All authors have to do is drop the word "The" from their Paleo Diet title.

Now, had I not registered paleodiet.com before he published his first book, he may have taken that for his domain name.

Unknown said...

My conclusion

no need to fear protein
no need to fear fat
no need to fear carbs
no need to fear the reaper

Jorgen Schäfer said...

A study lacking a control group is not really worth the paper … er, bits it's written on. Also, the "journal" it was accepted to is not peer-reviewed and an article they published actually (co-)won the IgNoble prize in 2006.

http://en.wikipedia.org/wiki/Journal_of_Internal_Medicine

George Henderson said...

I guess "Paleo diet" is a term that is joining "Mediterranean Diet" as denoting a spavined version of the original.

So when someone tests a high-SFA or low-protein diet Paleo diet they will need to find another term. I guess Perfect Health Diet will be the devalued term when that happens.

Of course for some purposes, such as resistance to oxidation, MUFA and SFA are virtually interchangable. There would be no issue with higher levels of PUFA over the time scales of these studies assuming that a) omega 6 and 3 are balanced, b) the subject is not already swamped in them. The salutary effects of DHA and EPA appear faster when these are added than any harmful effect of linoleic acid disappear when it is withdrawn.



@Jorgen, intractable hiccups are a serious if unusual condition, other cures used in the past include I.V. methamphetamine.

Charles Grashow said...

All three of the diets mentioned are VERY LOW in saturated fat - much less than 10% - I thought that a paleo diet was VEY HIGH in saturated fat - that saturated fat did not matter health wise. Am I mistaken?

Steven Hamley said...

Agreed. There was one paleo diet study where the macros of the paleo and other diet were 30P:30F:40C. The difference? Replacing dairy and grains with fruit.

Canola oil? And rapeseed oil has been used in other studies, really?

Charles Grashow said...

http://gokaleo.com/?p=1050

Josh said...

Also interesting that the total SFA decreased by more than half (-57%) on the paleo diet. Possibly relevant considering the impressive decreases in liver fat. The results were similar to another study which comparied two isocaloric diets with different levels of SFA and total fat. Here are the graphs of both studies showing reductions in liver fat.

Charles Grashow said...

http://jama.jamanetwork.com/article.aspx?articleid=1357266
Association Between Omega-3 Fatty Acid Supplementation and Risk of Major Cardiovascular Disease Events
A Systematic Review and Meta-analysis

Conclusion
Overall, omega-3 PUFA supplementation was not associated with a lower risk of all-cause mortality, cardiac death, sudden death, myocardial infarction, or stroke based on relative and absolute measures of association.

http://www.lecturepad.org/index.php?option=com_content&view=article&id=1103:re-analysis-of-sydney-heart-study-are-omega-6-fatty-acids-atherogenic&catid=65:diabetic-therapeutic-agents&Itemid=445

http://www.lecturepad.org/index.php?option=com_content&view=article&id=1104:commentary-response-to-jama-on-omega-3-fatty-acids&catid=47:prevention&Itemid=423

http://www.dhaomega3.org/Cardiovascular-Health/DHAEPA-Institute-Comments-on-Recent-Review-Omega-3-Supplementation-and-Cardiovascular-Events

http://www.texasgrassfedbeef.com/HTMLobj-5953/Response_to_JAMA_Sept_12_2012.pdf
Some of the responses from the scientific community regarding recent JAMA report.

http://www.wholefoodsmagazine.com/columns/vitamin-connection/amid-continuing-reports-fish-oils-effectiveness-flawed-studies-add-confu

http://www.drkarafitzgerald.com/omega-3-benefits

Steven Hamley said...

If anything, saturated fat is probably mildly protective of fatty liver by lowering oxidative stress. (There are several studies where very high saturated fat diets protected against fatty liver from excessive amounts of alcohol)

The liver fat is probably more related to less leaky gut >> less endotoxins in the bloodstream.

Perhaps the most important thing for fatty liver is choline. The dietary guidelines have really got to get their act together because they are recommending choline deficient diets. What's more, the adequate intake is based on the minimum amount for liver damage to not occur

Kade Storm said...

http://www.ncbi.nlm.nih.gov/pubmed/19901143

Horses for courses?

eulerandothers said...

Josh, what was the other study that compared two isocaloric diet with different levels of SFA and total fat?

STG said...

Charles:

Thank you for posting the info on omega-3s. I am so tired of all the omega-3 hype. I wonder if "paleo people" worried about omega-3/omega-6 balance or had easy access to omega-3 food sources in northern continental climates?

Josh said...

it was this one - http://www.ncbi.nlm.nih.gov/pubmed/15741262

Gabriella Kadar said...

STG, there have been several occasions in the past few years when I've sustained hand joint injuries or swollen finger joints. With the hand I waited 2 months to see if it would stop hurting. When a sales rep shook hands with me and I almost crumpled to the floor I decided it was time to do something about the situation. In situations like this I take large doses (8 to 12 capsules) of Harp Seal oil from Newfoundland. After 48 hours 90% of the pain was gone. I take them for a couple of weeks by which time the joints are back to normal for good. Large doses of fish oil upset my stomach but seal oil does not.

It doesn't help with muscle pain but it does resolve joint inflammation quickly if taken in therapeutic as opposed to supplement doses as mentioned in the last article referenced by Charles.

Lesley Scott said...

"But these studies are increasingly demonstrating that lower-to-low fat relatively higher PUFA diets, per USDA recs, may just not be a problem!" This comment reminded of the dude who ate the twinkies & junk food & lost weight - plus didn't his health markers improve? - ie. the first thing that matters overall is the total amount of energy consumed relative to what gets used up. Secondary, obviously, would be the quality of what you eat - but I wonder since the subjects in this Ryberg study were allowed to add stuff ad libitum, how many calories they were actually consuming. Also, I could be wrong but my impression is that olive oil is relatively harmless while the jury's sorta out on canola.

Evelyn aka CarbSane said...

Thanks for the clarification!

Evelyn aka CarbSane said...

Cordain's original diet allowed canola = rapeseed oil. He has changed his mind on this and softened his stance on sat fat.

Evelyn aka CarbSane said...

Thanks for the info on that journal! I would agree that w/o control most studies aren't worth much at all for "cause" , but they do provide some information that is helpful/meaningful. For example treatments for life threatening diseases cannot be ethically studied with a control group but if the treatment works? Granted this isn't quite as dire, but there were interesting outcomes here.

Evelyn aka CarbSane said...

I think the sat fat differential between the tested diets and the "paleo diet" is the big issue. I'm not speaking to the good or bad of any fat per se, just that none of these studies offer support for the paleo diet as practiced and should not be used in books as "proofs".

Evelyn aka CarbSane said...

There are certainly a segment of the population for whom sat fats are a problem.

Evelyn aka CarbSane said...

It is worth noting that one of the few LCHF cultures studied, the Inuit, consume enormous amounts of O3 as cold water mammal fat is loaded with it. Interestingly there is also a not-insignificant amount of odd chain fatty acids. The paleos consuming grass fed beef are NOT mimicking that diet!

Evelyn aka CarbSane said...

Personally I don't have an issue with canola. I prefer olive for dressings for taste and cook with palm kernel oil and butter (also for flavor reasons, PKO is tasteless) . But I think much of the PUFA issue is the use of veg oils in margarine = transfats. I only think PUFA per se is problematic in constant overnutrition where they might hang around the mitos long enough to become oxidized, etc.

My bottom line is that the results of various studies continue to be all over the map, and to me this means it cannot be PUFA per se. If it were, there would be consistency, and perhaps neg effect or no effect, yet we often see neg, no, or positive. That should not occur unless there's more to it!

eulerandothers said...

Josh, from the study you cite (http://www.ncbi.nlm.nih.gov/pubmed/15741262):
Dietary fat content modifies liver fat in overweight nondiabetic subjects.

'We have previously found a correlation between between the percent saturated and total fat in the diet and liver fat content.'

which points to this study:

(http://www.ncbi.nlm.nih.gov/pubmed/12606511)
Effects of identical weight loss on body composition and features of insulin resistance in obese women with high and low liver fat content.

'At baseline, LFAT correlated with the percent of fat (r = 0.44, P < 0.05) and saturated fat (r = 0.45, P < 0.05) of total caloric intake but not intra-abdominal or subcutaneous fat or fasting serum free fatty acids. '

LFAT=liver fat

From this same study:
' The decrease in LFAT was closely correlated with baseline LFAT (r = -0.85, P < 0.001) but not with changes in the volumes of intra-abdominal or subcutaneous fat depots, which decreased similarly in both groups. LFAT appears to be related to the amount of fat in the diet rather than the size of endogenous fat depots in obese women. '

and
'We found, however, a significant correlation between total fat and saturated fat intake and LFAT, raising the possibility that fatty acids derived from the diet may influence LFAT content.'

You say:
'Also interesting that the total SFA decreased by more than half (-57%) on the paleo diet. Possibly relevant considering the impressive decreases in liver fat.'

That seems to be the case, given both these studies. Decreases in liver fat occur during weight loss. In the study you cite, there wasn't weight loss, but there was decrease in LFAT. During the diet, 'The difference in fat intake was mainly a result of the difference in the intake of calories from saturated but also from mono- and polyunsaturated fat.' These are the authors' words, but the study isn't about saturated fat - it seems to me to be more about total fat.

The second study does look more closely at saturated fat.
It considers identical weight loss. The chart (Fig. 2) shows the effects of saturated fat on liver fat.

Emily Deans said...

I was just looking into some nasty studies showing quite a lot of trans fats in vegetable oils (not just margarine). The manufacturing process produces them, from 0.5-7% in many of the vegetable oils studied. They were all pretty old studies and it took the help of Victoria Prince (med student extraordinaire) to find them. Mike Eades tells me he has a whole raft of these old papers saying the same thing. Obviously high temperature makes this issue worse. I would stick to olive oil, butter, and coconut or palm oil for cooking fats.

Josh said...

Interesting stuff. So now there are 3 graphs. Just need some more studies that isolate the effect of SFA independently of total fat intake and weightloss to see how big of an effect each variable has.

Josh said...

Link not working above - here is the link for the graphs

eulerandothers said...

http://www.ncbi.nlm.nih.gov/pubmed/22668846
Formation of trans fats during food preparation.

Canola oil was the oil used.
There are some trans fats in canola oil (4 grams in a cup) but just 17 grams of saturated fat in that cup. There are no trans fats in a cup of butter, but 117 grams of saturated fat. Guess you pick your poison! Even olive oil has 30 grams of saturated fat in a cup.

Cooking vegetable oil doesn't seem to matter, though.

'Baking and stir-frying at normal and/or extreme temperatures do not significantly affect the amounts of trans fats. Likewise, heating oil to the smoking point during stir-frying may decrease the amount of polyunsaturated fatty acids because of oxidative degradation.'

Subcalva said...

I think the problem with PUFA is that it turns rancid so easily. Eating fresh products with PUFA in them is probably OK but as Julianne's Paleo and Zone Nutrition blogged about it turns out that products you think would be OK like high quality extra virgin olive oil is actually rancid and that people don't notice because they are used to the taste!

It always make me think of omega-3 capsules and how long they have been sitting on the shelf before being eaten. I wish someone would test them if they are rancid.

Charles Grashow said...

http://www.nytimes.com/2013/02/24/magazine/the-extraordinary-science-of-junk-food.html?hpw&pagewanted=all

The Extraordinary Science of Addictive Junk Food

Diana said...

I'm a little confused about abdominal fat being classified as ectopic or subcutaneous. If you have an inch of fat on your abdomen, what is that?

Evelyn aka CarbSane said...

Abdominal fat is categorized as visceral or subQ. Whatever you can pinch is subQ. Visceral is under the muscle wall within the abdominal cavity, around the organs. There is evidence that upper body subQ fat -- at least deep fat -- is related to metabolic disorders as is visceral. Waist circumference cannot distinguish but is a pretty good (if imperfect) marker.

Ectopic fat is fat stored in non-adipose tissue -- including organs like the liver. Yet another thing Dr. Eades had a hand in confusing people about for fun and profit in the abominable 6 Week Cure. Liver fat is not belly fat!

Diana said...

That is what I thought but I see so much confusion I wasn't sure. I have more subQ belly fat now than I did 20 years ago, even though I weigh less. (Dammit.)

Evelyn aka CarbSane said...

@Emily -- Interesting. I don't use a lot of oil so it tends to be one of those things I don't worry over.

@Subcalva -- Yeah, I wonder about my olive oil since I don't use a whole lot it sits around :(

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