Recently there was a coordinated media blitz to promote the results of a study that was published in the Annals of Internal Medicine, which claimed that adults should, “…continue current unprocessed red meat consumption…[and]…continue current processed meat consumption”
Now those are some pretty remarkable findings, given that in the US 1 out of every 4 deaths is caused by heart disease. In real numbers, heart disease kills more than 610,000 lives each year. For comparison, that’s the same number of people who die from all forms of accidents, strokes and diabetes combined.
This study was produced by a group calling itself “NutriRECS” that claims:
NutriRECS is an independent group with clinical, nutritional and public health content expertise, skilled in the methodology of systematic reviews and practice guidelines who are unencumbered by institutional constraints and conflicts of interest, aiming to produce trustworthy nutritional guideline recommendations based on the values, attitudes and preferences of patients and community members[.]sic
From what I can gather, no one is funding this group. No sources of funding are listed on the site. No sponsorships are listed. No solicitations for donations are present. No items are being listed for sale. No conflicts of interest are listed in the study (besides the fact that all of the authors listed that they eat red meat multiple times per week). This group seems to magically produce studies that go against hundreds of previous dietary guideline reviews for free!
Something else struck me as a bit odd. In their publications section, all of the previous studies that they did on nutrition were on the benefits of probiotic supplementation. Hmmmm…..
When digging into the study, it looks like a handful of supplemental studies were used as the basis for their recommendations, so let’s take a look at those.
- Study 1: Reduction of Red and Processed Meat Intake and Cancer Mortality and Incidence: A Systematic Review and Meta-analysis of Cohort Studies
- Role of the Funding Source: This study received no external funding or other support.
- Study 2: Patterns of Red and Processed Meat Consumption and Risk for Cardiometabolic and Cancer Outcomes: A Systematic Review and Meta-analysis of Cohort Studies
- Role of the Funding Source: This study received no funding.
- Study 3: Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: A Systematic Review of Randomized Trials
- Role of the Funding Source: This systematic review was conducted without financial support.
- Study 4: Red and Processed Meat Consumption and Risk for All-Cause Mortality and Cardiometabolic Outcomes: A Systematic Review and Meta-analysis of Cohort Studies
- Primary Funding Source: None. (PROSPERO: CRD42017074074)
- Study 5: Health-Related Values and Preferences Regarding Meat Consumption: A Mixed-Methods Systematic Review
- Primary Funding Source: None. (PROSPERO: CRD42018088854)
Wow – these are some seriously motivated altruists! I’m guessing these doctors must all be living under bridges begging for food.
If you take the time to review the studies, you’ll see that what they actually found was that there was either a very small correlation showing a reduction in red meat intake reduced cancer and heart disease risk or they found no relationship existed at all. This begs the question of why they would issue a guideline saying people should continue eating red meat if they found no good cause to do so.
There is actually a very good reason why they found no correlation between red meat consumption, cancer and heart disease risk in their research. When they looked at cross-sectional population studies, they completely ignored the fact that, due to known statistical power problems, no correlation is expected to be present in the data. To quote one study on the subject:
The confounding that results from the uncontrolled conditions under which most epidemiologic observations are made is sufficient to undermine their validity with respect to investigation of the relationship between diet and serum cholesterol. In this paper, the authors show, using both a mathematical model and referring to empirical data, that if certain variances are sufficiently great, even when there is cause and effect, correlation coefficients close to zero would be expected from the actual data of a cross-sectional study. Cross-sectional designs are therefore not suitable for studying this relationship.
And when they looked at randomized trials of red meat reduction, the studies they chose to look at were all funded by the meat industry! These studies used all sorts of easy gimmicks to hide bad outcomes, like reducing red meat intake but not controlling for cholesterol or saturated fat intake, not controlling for baseline cholesterol values, etc.. etc..
When we look at metabolic ward studies, where they lock people in a lab and completely control their diet, we can see that the addition of saturated fat raises cholesterol so consistently that you can actually create a mathematical formula that will predict exactly how much saturated fat is required to raise your cholesterol by a given number of points. And it’s a statistical certainty that the higher your serum cholesterol values are, the greater your risk for heart disease. This is how lab data proves, beyond any doubt, that eating red meat will increase your risk of heart disease.
The Annals of Internal Medicine is actually being sued by a group of medical doctors over publication of this absurd study due to the significant scientific errors it contains. Dr. Neal Barnard of the Physicians Committee on Responsible Medicine is interviewed about the lawsuit:
From a previous article I wrote, the evidence against eating animal products and low carb diets is simply overwhelming. Harvard researchers estimate 1 out of 3 early deaths could be prevented by people simply not eating meat.
Studies on children and adults have shown increased arterial stiffness on low carb diets. Saturated fat has been directly observed to cause inflammation, as well as impair endothelial function. A high saturated fat meal also leads to an acute post-meal increase in circulating endotoxins, which is especially terrible for diabetics. Saturated fat promotes lipotoxicity through inflammation which leads to insulin resistance.
We also know that meat, in particular processed meat, is a known carcinogen. The current evidence for the carcinogenicity of processed meat places it in the same category of evidence as cigarettes. Animal protein is known to increase IGF-1, a cancer promoting hormone. Several forms of cancer, such as colon cancer and lymphoma, have been directly linked to meat consumption.
It’s also worth noting that when people are placed on ketogenic diet, their athletic performance suffers. Given that we know high fat diets impair endothelial function, stiffen arteries, reduce blood flow and cause hyperlipidemia, it makes sense that a randomized control trial would show a reduction in athletic performance for people on a ketogenic diet.
Here’s a study showing the impact of an ad libitum (eat as much as you want) whole food vegan diet on disease markers after just 7 days. The study notes that, “The median weight loss was 1.4 kg. The median decrease in total cholesterol was 22 mg/dL. Even though most antihypertensive and antihyperglycemic medications were reduced or discontinued at baseline, systolic blood pressure decreased by a median of 8 mm Hg, diastolic blood pressure by a median of 4 mm Hg, and blood glucose by a median of 3 mg/dL. For patients whose risk of a cardiovascular event within 10 years was >7.5% at baseline, the risk dropped to 5.5% at day 7.” – so that’s a massive improvement in all disease markers after just a week on an unrestricted low fat whole food vegan diet.
Here’s another study showing a vegan diet, where portion sizes, energy intake and carbohydrate intake were unrestricted, did better than a calorie restricted American Diabetes Association diet at getting blood glucose and lipids under control. Dr. Greger explains exactly how saturated fat impairs insulin sensitivity in this short video.
In conclusion, the evidence shows that low carb high fat diets are atherogenic, cancer causing and do not lead to better long term weight loss or disease prevention when compared to other forms of diets, even though they may improve blood lipid profiles due to the weight loss they induce. On the other hand, whole food plant based diets have been proven to reverse atherosclerosis, reverse some forms of cancer, reverse type 2 diabetes and lower chronic disease risk.
Now if you want some real science, watch this: