Nutrition "facts"
I've been hearing a lot recently about a new Netflix documentary called "What the Health," so I decided to watch it. Two of the starring physicians in the film are also frequent authors of articles that appear on my facebook feed.
The first is the founder of NutrtionFacts.org - a site where "a real doctor!" posts alarmist videos about food. This real doctor is Michael Greger, a General Practicioner. GP is not really something people do anymore. If you have ever been to see a doctor, they probably have done a residency to become board certified in a specialty. Dr. Greger graduated from medical school and then went on to make videos about being vegan citing cherry-picked sources. His "job that pays the bills" is working for the Humane society. I'm not saying there's anything wrong with that, just the fact that he and his followers lean so heavily on the "M.D" and yet he's not a doctor that sees patients. I'm pretty sure the last time he used a stethoscope was to wear it for a photoshoot in whole foods.
Another favorite source is the Physicians Committee for Responsible Medicine (PCRM), an organization which the American Medical Association (AMA) has denounced as a pseudo-physicians group. The primary focus of PCRM is promoting a "plant-based diet" (veganism). The head of this group recently wrote a book about the evils of cheese, and has affiliations with PETA. Both sources dabble in science and evidence, but completely overstate the benefits of a vegan diet while ignoring any evidence to the contrary.
Now, I do not have any problem with veganism. I'm actually not a huge meat eater myself, and think that people should do what works for them as individuals to maintain health. I do have a problem with people trying to raise alarm, push their viewpoints on others and spreading pseudoscience. A college humor video puts the problem with this best:
The video above shows confirmation bias, and is exactly the problem with this documentary. They do support all their claims with references. But they don't even acknowledge the massive amount of data refuting those points. The website for the documentary conveniently lists all the claims and sources. The amount of sources listed as "nutrtionfacts.org video" and "PCRM" are high. I would immediately discount those as reputable sources. They are opinions. Dr. Harriet Hall, a retired Air Force physician does a great job at refuting some of these claims
One important thing Dr. Hall points out, which is common EVERYWHERE, is the use of relative risk versus absolute risk reduction. Anyone trying to prove a point will use relative risk reduction because it sounds better. One website I love that explains absolute risk reduction (or rather the inverse of it) is theNNT.com
One of the biggest points tried to hammer home in "what the health" is that eating meat, not sugar and carbs as is widely believed, is the cause of diabetes . Umm what!?!? Much like ZdoggMD's reaction, my jaw was on the floor as they showed an animation of fat blobs blocking sugar's entry into cells. Since I had never heard of this I wanted to investigate this particular claim in detail. Here's the entire list of sources for this claim, posted on their website, along with my opinion of each source:
"DIABETES IS NOT CAUSED BY EATING A HIGH CARBOHYDRATE DIET OR SUGAR"
Greger, M.D, Michael "What Causes Insulin Resistance?" NutritionFacts.org video. Volume 33. January 6th, 2017 - an opinion video - just as much a reliable source as the documentary itself.
"Diet and Diabetes: Recipes for Success". Physicians Committee for Responsible Medicine
Barnard, Neal, et al "Meat Consumption as a Risk for Diabetes". Nutrients. 2014 Feb: 6(2) 897-910 - a web article which sites the NEJM article below as the source for, "New information suggests that fat in animal products and oils interferes with insulin’s ability to move glucose into the cells"
Petersen, Kitt Falk, et al "Impaired Mitochondrial Activity in the Insulin- Resistant of Patients with Type 2 Diabetes". The New England Journal of Medicine 2004; 350: 664-671 - ah, finally! the one primary source. NEJM is one of the most highly respected medical journals. The first thing I noticed about this study is the incredibly small n. They found 3 men and 11 women with insulin resistance to study. But small numbers doesn't mean it's not still good science. They did biopsies on those subjects with insulin resistance and compared them to controls and found that they had more intramuscular lipid content. There are 2 ways to explain more fat in the muscle - 1. more is being delivered or 2. less is being broken down. They checked to see if more fat was being broken down elsewhere in the body and found that wasn't the case. Then they checked the activity of the mitochondria in the muscle cells and found that they were using less energy in the insulin-resistant patients. Their main conclusion was that diabetes may be caused by a GENETIC problem with MITOCHONDRIA! They said absolutely NOTHING about how diet might influence this!!!
"CARBOHYDRATE CONSUMPTION IS INVERSELY RELATED TO DIABETES"
Ahmadi-Abhari, Sara, et al "Dietary intake of carbohydrates and risk of type 2 diabetes: The European Prospective Investigation into Cancer-Norfolk Study". British Journal of Nutrition: (2012) 111, 342-352 - this study found while controlling for everything else, fructose and glucose consumption had an inverse relationship with the development of diabetes. Unlike the documentary they acknowledge the conflicting data that exist on the topic. They also say that "fruits and vegetables are likely to account for the observed associations, as they are the main sources of fructose and glucose and have been shown to be inversely associated with the risk of incident diabetes" ... FRUITS AND VEGETABLES! These people were not given pure sugar that decreased the risk of diabetes. I'm pretty sure everyone agrees that fruits and vegetables are good for you. Yes, they have sugars in them.
Roberts, Christian K, et al "Effect of a diet and exercise intervention on oxidative stress, inflammation and monocyte adhesion in diabetic men". Diabetes Research and Clinical Practice. 73 (2006) 249-259 I had never heard of this journal so I checked out its impact factor (a measure of how often it is cited) and it was pretty low at 0.8. Doesn't make the research invalid, just interesting to note. This is another small study. 13 Men in LA - hardly what I would call a generalizable population. This study put people on a diet and a lot of molecular markers changed. It's incredibly detailed and tedious to read. I couldn't stand to read the whole thing, but couldn't see any way this proves carbohydrate consumption is inversely related to diabetes.
"ONE SERVING OF PROCESSED MEAT PER DAY INCREASED RISK OF DEVELOPING DIABETES BY 51%"
Pan, An, et al "Reat meat Consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis". American Journal of Clinical Nutrition. August 2011 This is an interesting study. They have 3 large cohorts of subjects, all of which are health professionals - doctors, nurses, dentists, etc. I wouldn't call this a representative population, but it's a large and interesting study. They found positive correlations between red meat consumption and diabetes. However they also found positive correlations with red meat consumption and increased BMI, smoking and decreased physical activity. So basically unhealthy people were overall unhealthy. How could they separate out those factors? This was also an observational study and therefore cannot imply causation. Anyways, this is where the film got the 51% number - again a relative risk, not an absolute risk.
Micha, Renata, et al "Unprocessed Red and Processed Meats and Risk of Coronary Artery Disease and Type 2 Diabetes- An Updated Review of the Evidence". Current artherosclerosis reports. 2012 Dec;14(6): 515-524 This is actually almost the same as the article above, with the same numbers. Just published a year later and including some more information about CAD risk. I wish I would have started with this one because it's much easier to read than the one published in Journal of Clinical Nutrition. An important point for both of these is that the strongest risk was with processed meat consumption. What the Health likes to lump all meat consumption in with processed meats.
So there's the "evidence" that meat causes diabetes. Here's a fraction of the evidence to the contrary:
Did know that type 2 diabetes has more genetic basis than type 1? Turns out complex diseases like this are multifactorial, and can't be boiled down to something as simple as - be a vegan to cure all that ails you! A great resource I found in doing this research is this website. This is an internal medicine physician that provides balanced reviews of evidence about nutrition. From his site, "In a given crowd, the odds are that most of the people eat very different diets, some of them have very strong convictions about their diet, and several people in the crowd that have strong dietary opinions will have completely opposite diets. This means that despite our strong opinions about diet, much of what we believe in must be wrong!"
Finally. I just had to mention that one of the physicians in the "What The Health" documentary said that milk was a form of institutionalized racism.... What!?!? (p.s. there are a surprising number of racist milk memes on the internet!)
