That New Volek (& Phinney) Study: Part I The Journal Article & The Headlines
Yes folks! Yet another study has hit the presses to tell you everything you thought you knew about nutrition is wrong, wrong and more wrong!!
The Journal Article
Effects of Step-Wise Increases in Dietary Carbohydrate on Circulating Saturated Fatty Acids and Palmitoleic Acid in Adults with Metabolic Syndrome
Brittanie M. Volk, Laura J. Kunces, Daniel J. Freidenreich, Brian R. Kupchak, Catherine Saenz, Juan C. Artistizabal, Maria Luz Fernandez, Richard S. Bruno, Carl M. Maresh, William J. Kraemer, Stephen D. Phinney, Jeff S. Volek.
All twelve eh? Hmmmm.....
It is published in PLOS One which promises the reader that the manuscript has received "fair and rigorous peer review". It is also, ultimately, a pay to play journal ($1350 to publish) -- the type I have become increasingly cynical of. Journals like PLOS One should be for the "anti-establishment" types, or those looking to crack into the published research game. It used to be a big deal to be a first author on a research paper, or any author on one. Now that is more or less a joke. It used to be that submitted papers were rigorously reviewed, but that isn't even a given any more in the prestigious journals. It used to be that papers were actually reviewed for factual content, data presentation (or lack thereof), etc. And perhaps most importantly of all, it used to be that they were critically reviewed for the interpretation of the results. Lead authors (or now the trailing "group leader") held credentials in the field of publication. This is where I say that PLOS One could be a proving ground for those of a more interdisciplinary bent, those perhaps lacking the formal letters but bringing the goods with quality research, those lacking the gravitas of a big name researcher or institution to get published in a "real" journal. (And yes, there was a time not all that long ago that these existed. That model was not without its own drawbacks, but I'll take it any day over the mess we have now.)
What we have with this study and its venue of publication, are two low carb icons slumming it in the pay-to-play bouncie house!
Here is what you do to submit to PLOS One. You conduct a study and write it up, follow some guidelines for formatting, agree to share your data (I'll be following up on this one at some point), etc. etc. There's the nice thing that funding and competing interests are pretty up front and center. But the review process of PLOS One seems hardly rigorous. An academic editor is assigned once staff has given the manuscript a cursory once over. This editor can then accept, return for minor or major revisions, or reject. "The Academic Editor decides whether reviews from additional experts are needed to evaluate the manuscript. The majority of PLOS ONE submissions are evaluated by two external reviewers, but it is up to the Academic Editor to determine the number of reviews required." If external reviewers raise objections, the editor "may choose to send the [resubmitted] manuscript back to external reviewers, or may render a decision based on personal expertise"
When you submit a manuscript, you are asked to "Please recommend 2-5 reviewers to comment on your paper. Suggesting reviewers helps us ensure that your paper will experience a swift and expedient review process. However, please note that we are unable to guarantee that your suggested reviewers will comment on your paper. Remember that you can suggest any qualified scientist to review your paper; your suggestions need not (and should not) be PLOS ONE academic editors." You also get to "Oppose Reviewers. If there are people you think should not be invited to review your paper, please provide their information here, as well as the reason for opposition. If there are any Academic Editors you think should not be invited to review your paper, please also provide their information here, making clear that they are an editor, not a reviewer. You must also provide an explanation for your opposition.
Alrighty then! It would be interesting to know the stats on how often PLOS One uses external reviewers at all. In that vein, when reviewers are used, another interesting stat would be how often they are from the list suggested by the authors. Who reviewed this paper? Anyone who wishes to help me find this out is welcome to so long as it is with the understanding that I am not suggesting harassment of any sort. This is in the spirit of transparency that PLOS One purports to foster. I do know that PLOS One lists the Editor: Pankaj K. Singh, University of Nebraska Medical Center, United States of America. He is one of over 6000 editors. Singh is a cancer specialist. More importantly, when searching on areas of expertise, he is NOT listed among those for lipid metabolism (82), lipids (120), cardiovascular diseases (46), diabetes (27), or obesity (166). In this regard it would seem imperative that independent external peer review be conducted. Was it?
PLOS One is big on transparency for funding and competing interests. Kudos! From this we learn that the study was funded by usual disinterested parties low carb advocates demand. Sugar and grain industry funded studies are dismissed out of hand. So was this funded by the NIH? Nope ... sorry. It is funded by Big Dairy (Dairy Research Institute), Big Cow (The Beef Checkoff) and Huevo Grande (Egg Nutrition Center).
Oh ... and The Robert C. and Veronica Atkins Foundation. Why is this not listed in the Competing interests? After all,
Volek has been the recipient of Atkins Foundation funding before. They both sit on the advisory board of Atkins Nutritionals. Don't give me the disclaimers about how Atkins Nutritionals and the Foundation are separate entities. In DANDR, Atkins wrote (there's more than a tinge of irony here!):
Why have you never published your findings on the various benefits of the Atkins Nutritional Approach in a scientific journal?
I am a full-time practitioner and not a researcher. As a physician I am responsible for the health of my patients and would never use some of them as a control group in the interest of research.
But I have taken a series of important steps to share the benefits of the Atkins Nutritional Approach with the medical community throughout the world. Working with a number of leading academic and research institutions, I have developed a series of Continuing Medical Education courses for health professionals. These courses explore the available research and clinical relevance of controlled carbohydrate nutrition.
Additionally, the Dr. Robert C. Atkins Foundation sponsors further research in all aspects of controlled carbohydrate nutrition. The Foundation is funded through Atkins Nutritionals Inc., our food products and nutritional supplements company. ANI, as I call it, has the added benefit of helping to supply the demand we now see of people seeking controlled carbohydrate foods. All of our products are developed to support the Atkins Nutritional Principles. Interestingly, our products have encouraged other food companies to develop additional new products.
Add to this that Volek and Phinney are co-authors (with Westman) of The New Atkins book, and two of their own low carb advocacy books. Volek is also selling UCAN superstarch marketed to low carb adherents. These are commercial competing interests that most certainly at this point influenced the study design here. They go way beyond funding source or any influence that Big Whatever might have. How can one expect any diligence in the peer review department if such overt conflicts of interest are not "caught" during the submission process??
Now, just because this is in PLOS One is not a reason to dismiss the study. There will be plenty of time to do that on its merits or lack thereof. But my reason for pointing out the journal and its review process is because this study would likely not pass muster in a real subject-dedicated journal. Articles published in pretty much every journal these days should still be viewed critically, but especially those of the pay-to-publish variety.
Recent meta-analyses have found no association between heart disease and dietary saturated fat; however, higher proportions of plasma saturated fatty acids (SFA) predict greater risk for developing type-2 diabetes and heart disease. These observations suggest a disconnect between dietary saturated fat and plasma SFA, but few controlled feeding studies have specifically examined how varying saturated fat intake across a broad range affects circulating SFA levels.
This study adds little further information as circulating free fatty acids were not assessed, only the SFA content of fasting triglycerides (mostly VLDL). But onward ...
Sixteen adults with metabolic syndrome (age 44.9±9.9 yr, BMI 37.9±6.3 kg/m2) were fed six 3-wk diets that progressively increased carbohydrate (from 47 to 346 g/day) with concomitant decreases in total and saturated fat. Despite a distinct increase in saturated fat intake from baseline to the low-carbohydrate diet (46 to 84 g/day), and then a gradual decrease in saturated fat to 32 g/day at the highest carbohydrate phase, there were no significant changes in the proportion of total SFA in any plasma lipid fractions. Whereas plasma saturated fat remained relatively stable, the proportion of palmitoleic acid in plasma triglyceride and cholesteryl ester was significantly and uniformly reduced as carbohydrate intake decreased, and then gradually increased as dietary carbohydrate was re-introduced.Again, this observation is limited to the fatty acid content of fasting triglycerides.
The results show that dietary and plasma saturated fat are not related, and that increasing dietary carbohydrate across a range of intakes promotes incremental increases in plasma palmitoleic acid, a biomarker consistently associated with adverse health outcomes.
Palmitoleic acid is a MUFA and while it may be true that it can act as a biomarker, there is an insanely huge amount of research against there being any direct deleterious mechanism of action for this fatty acid. To the contrary, palmitoleic acid is often shown to have protective, insulin sensitizing effects. More on that later, but come on. How can you write that when even perusing Wikipedia should cause pause!
But let me ask you this. When was the last time you heard that saturated fat caused an increase in the saturated fat circulating in your blood and that THIS was the cause of heart disease? Answer: Never! There's much more to come regarding the actual study ... but first ...
Below is the first page of a Google search I did today about this study. Just look at some of those headlines!
Here is the Daily Mail!
- Food laden with saturated fat does not drive up levels of the 'junk' nutrient in the blood, contrary to popular opinion, research suggests.
- Higher consumption of carbohydrates, not saturated fat, was associated with changes linked to diabetes and heart disease, scientists found.
- The discovery turns on its head the widely-held view of the harmful effects of eating too much saturated fat.
This isn't just misinterpretations of the study, it comes from Volek's own statements. From MedicalDaily.com
A recent study supported by the Dairy Research Institute, the National Cattlemen's Beef Association, and the Egg Nutrition Center has found that doubling or even tripling the amount of saturated fat in our diets will not lead to increases of total saturated fat in our blood.
"People believe 'you are what you eat,' but in reality, you are what you save from what you eat," Jeff Volek, a professor of human sciences at The Ohio State University, said in a statement. "The point is you don't necessarily save the saturated fat that you eat. And the primary regulator of what you save in terms of fat is the carbohydrate in your diet. Since more than half of Americans show some signs of carb intolerance, it makes more sense to focus on carb restriction than fat restriction."
That last statement is not supported by anything this study looked at. We're talking levels around 3% of fasting triglyceride fatty acids, not stored body fat!
Volek ought to take a step back ...."There is widespread misunderstanding about saturated fat. In population studies, there's clearly no association of dietary saturated fat and heart disease, yet dietary guidelines continue to advocate restriction of saturated fat. That's not scientific and not smart," Volek added. "But studies measuring saturated fat in the blood and risk for heart disease show there is an association. Having a lot of saturated fat in your body is not a good thing. The question is, what causes people to store more saturated fat in their blood, or membranes, or tissues?
I could provide you with more, but I'll end this with the press release from his new institution of academic affiliation (wonder if he'll rename UCAN? ) OSU:
Doubling or even nearly tripling saturated fat in the diet does not drive up total levels of saturated fat in the blood, according to a controlled diet study.
However, increasing levels of carbohydrates in the diet during the study promoted a steady increase in the blood of a fatty acid linked to an elevated risk for diabetes and heart disease.
The finding “challenges the conventional wisdom that has demonized saturated fat and extends our knowledge of why dietary saturated fat doesn’t correlate with disease,” said senior author Jeff Volek, professor of human sciences at The Ohio State University.
Apparently he's not familiar with Yerushalmy & Hilleboe, but I digress ... As you'll see when I discuss the study itself, the above are taken out of context and are wildly misleading. This study does nothing to extend any knowledge or turn conventional wisdom on its head.
SIGH ... And I haven't even mentioned the myriad of flaws in the study itself ... hope to get to that very soon!
Part II ~ More on Journal Choice, Funding and Thoughts on Press Quotes
Part III ~ Science or Advocacy?
Part III ~ Science or Advocacy?