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Want To Buy: A Placebo

A well-designed/performed, double-blind, randomized, placebo-controlled trial provides a high level of certainty about the effectiveness of an intervention. In scientific training, the need to utilize a placebo relative to your variable of interest is one of the first things you learn when designing an experiment. As many in the basic sciences and evidence-based medicine fields have become more interested in nutrition and its impact on health/biology (their interest is well-justified), there has been insufficient appreciation for the difficulty in performing nutrition research. This day 1 principle of "placebo-controlled" poses a particular challenge for many nutrition experiments: there is no placebo.  Consider an example that actually plagued causal inference in nutrition history: It was known that feeding diets high in saturated fatty acids was associated with higher LDL. Does that mean that saturated fat raises LDL? How would you design a study to show...
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Cute Mayo Clinic Videos. Bad Science

The prestigious Mayo Clinic regularly gets itself into hot water across evidence-based medicine and skeptics circles (see here ) for its heavy promotion of questionable science; Mayo is particularly entrenched in the complementary/alternative/integrative/functional medicine (CAM/IFM) movement that is taking academic medical centers by storm (it even has a peer reviewed publication about its CAM use). Mayo, like other famous clinics, seems more than happy to promote its clinic with low-to-no evidence modalities that have been re-branded under the CAM/IFM movement. There's a nutrition video that Mayo has produced and is circulating around the social media spheres. I've seen it before but today it made me particularly annoyed so here we are. The video covers the role of a whole foods plant-based diet as 'powerful medicine' with a focus on cancer. You can see the video embedded below. A link to their tweet with the video can be found here   and its also up on their YouTub...

On PURE

The PURE macronutrients studies were published in the Lancet journals today and the headlines / commentaries are reminding us that everything we thought we think we were told we knew about nutrition is wrong/misguided, etc. Below is my non-epidemiologist's run down of what happened in PURE. A couple papers came out related to PURE, but the one causing the most buzz is the relationship of the macronutrients to mortality. With a median follow up of 7.4 years, 5796 people died and 4784 had a major cardiovascular event (stroke, MCI). The paper modeled the impacts of self reported dietary carbohydrate, total fat, protein, monounsaturated (MUFA), saturated (SFA), and polyunsaturated (PUFA) fatty acid intakes on cardiovascular (CVD), non-CVD and total mortality; all macros were represented as a percentage of total self reported energy intakes and reported/analyzed in quintiles (energy intakes between 500-5000kcals/day were considered plausible..). All dietary data was determined by a ...

AHA on Fats and CVD

The American Heart Association (AHA) released it's Presidential Advisory on Dietary Fats and Cardiovascular Disease this week and the responses have been all over the place (see medscape ,  science-based medicine , HNR , Gary Taubes , Cardiobrief ). Here's my summary/take: There's nothing terribly new about this advisory; it's relatively the same line of thinking/evidence that the AHA has used to support it's recommendations in the past, so regular followers of the field will not read this report and be too shocked. The most novel aspect of it is an updated meta-analysis of 4 diet-heart trials which the AHA generated. The new meta analysis comes about because there have been multiple meta-analyses which have attempted to address this issue over the past several years, and they don't all align nicely - see here , here , here . Why? Because the study inclusion criterion that are used are often not the same. Shorter term trials have consistently shown that satu...

Another Year In Nutrition: 2017

My thoughts on Nutrition in 2017 - hopes, concerns, expectations and things to look out for: 1. The National Academies of Medicine (NAM) - NAM is making moves on laying a framework for addressing chronic diseases within the context of the dietary reference intakes. It'll be interesting to see what directions NAM moves in and how actionable this framework will be. Nutrition has a long history of relying on variable qualities of evidence to achieve its recommendations that's led to a lot of talk about how to make nutrition policy. When it comes to addressing chronic disease, we have very few validated surrogate outcomes (e.g. LDL) to link nutrient intakes to, and major parts of the field of medicine are moving away from these due to their limitations . Nutrition has a really poor history of conducting large randomized controlled trials with meaningful, interpret-able outcomes (e.g. MRFIT, WHI, PREDIMED), especially when brought together in seemingly endless variations of m...

Teaching Nutritional Genomics? Here are some Resources!

The Dietitians of Canada's Practice-Based Evidence in Nutrition recently posted a blog titled " Nutritional Genomics in the Dietetics Curriculum - How Far Have We Come? ". The post summed up some recent research suggesting that dietetics professionals and students don't feel confident that they have a strong knowledge base regarding nutritional genomics, but are eager to learn more! This finding comes at a time when the Academy of Nutrition and Dietetics' Accreditation Council for Education in Nutrition and Dietetics has released their draft Future Education Model Accreditation Standards, highlighting the need for an understanding of the basic concepts of nutritional genomics. As the field moves forward and needs to teach nutritional genomics/critically evaluate the field, it's important to have relevant resources to understand the basics. Below are a few resources which might help! If you have any questions about nutritional genomics or topics in molecular nu...

JAMA Internal Medicine - Sugar Industry

A few folks reached out to me to ask if I'd seen the recent JAMA Internal Medicine piece on the Sugar Industry's influence of nutrition science back in the 1960's. Several publications have covered the topic, some fair, some oversimplifying the situation, few adding sufficient context - for a roundup of prominent links, see the following:  1 , 2 , 3 , 4 , 5  , 6 . Most of the links and published commentaries either directly or implicitly state that the Sugar Research Foundation (SRF) paid researchers to think in some way and write research for them - alas, the nature of the files uncovered can't confirm such a relationship; the review's authors even note this in their limitation section: "There is no direct evidence that the sugar industry wrote or changed the NEJM review manuscript; the evidence that the industry shaped the review’s conclusions is circumstantial". Before I mention any context that I think is relevant, let's start off by that t...