Now we’re getting somewhere. The first three chapters of this book have been good, but they were building a foundation. Rodgers and Wolf are starting to make their case.
The authors draw our attention to the problems with nutritional research at the start of this chapter. This was a gratifying read because they make the same case I did months ago when discussing various anti-meat studies. That’s to say, observational research is the worst kind of research and is, at best, a jumping off point to further study. Ultimately, observational studies that rely on data like the Nurses’ Health Study can only show correlation. They cannot prove causation.
For the layman, this may be a difficult concept to wrap one’s head round. The authors know this and give the example of people who eat hotdogs are more likely to have heart attacks. But does this mean hotdogs cause heart attacks? The answer is maybe, but a true scientist would have to do further studies in order consider other factors. Rodgers and Wolf stick with the hotdog eaters and consider some other data. For example, suppose hotdog eaters tend to eat their dogs with a big bun, chips and a soda. Suppose also that hot dog eaters tend to smoke more or avoid vegetables or avoid exercise? Maybe these factors contribute to or are the cause of heart attacks. As to cancer, hotdogs are full of nitrates. Is it the nitrates or the meat that is the cause?
You get the point right? The authors tell us these are confounding factors that must be considered. Unfortunately, our authors argue that those who are fighting a war against meat and meat eaters very often do not consider confounding factors. Instead, they make the logical fallacy of correlation proves causation or post hoc ergo propter hoc. To hammer the message home, our authors point out to the strong correlation between the number of films Nic Cage appears in per year with the number of deaths by drowning in swimming pools. The data is striking. Those who argue that meat causes X, Y and Z using only observational data would have to also argue that Nic Cage causes pool drownings if they want to be logically consistent. We can see the absurdity of this argument. Is the case against meat equally absurd?
Another key problem with observational studies is that the people who respond to questionnaires often lie or forget or hold false memories. Do you know how many onions you ate in the last three months? Glasses of wine? Amount of broccoli? Meatballs?
This type of data has a host of problems that need to be honestly faced when being used. Indeed, they should be a jumping off point to further study. But what should the layman do when reading these studies that use solely such problematic information? The authors tell us: the layman needs to ask more questions. Here are a few that are mentioned:
- Were there conflicts of interest among the authors?
- Who paid for the study?
- Did a company with vested interests fund the study?
- Were the researchers vegan or vegetarian?
- What foods were tested? How was the information about the foods eaten collected?
- How many participants? Who were the participants? Were the participants human?
The authors conclude that this is not what tends to happen with those who attack meat. These people take correlation as rock solid proof of causation: a “tenuous connection is used as the basis for sweeping health recommendations.”
Ancel Keys and the McGovern Commission
The authors then go on an interesting tour of history explaining how we got here. Where did the war on meat start? We learn about Ancel Keys and his “arguments” against fat and the politically motivated McGovern Commission. If you don’t know the Keys story, I’d suggest you go and find it. Low Carb Down Under is a good place to start on Youtube. He is the prime mover on the war against saturated fat and by extension meat. Moreover, the McGovern Commission launched the high carbs, low fat craze starting in the 1970s that we still live with today. When scientists asked for more time to collect data supporting McGovern’s sweeping dietary guideline changes, the American Senator stated “We Senators don’t have the luxury that a research scientist does of waiting until every last shred of evidence is in.” Thus started a five decade war on fat and meat and promotion of carbs, vegetable oils and the like. Thank you Mr McGovern. Thank you Mr Keys.
Does Meat Cause Cancer, Heart Disease or Obesity?
The authors spend the rest of the chapter looking at some of the data used to attack meat. For cancer a lot of data comes from the International Agency for Research on Cancer (IARC). The authors do fine work explaining how the data used by this agency is hugely misleading even when it comes to processed meat. The IARC categories fresh meat as “probably” cancer causing. Rodgers and Wolf note, however, that there is no strong evidence to support this claim. Indeed, the flawed correlation proves causation data comes mainly from Western countries. Similar studies from Asia show little or no correlation between fresh meat and cancer. What to make of this? Confounding factors: “The incidence of colorectal cancer may be related to causative factors other than meat consumption, such as ethnicity , dietary habits, alcohol consumption, smoking, stress, exercise, medical check-up frequency, or environmental pollution.”
Meat and heart disease is also debunked. It’s the same old correlation proves causation fallacy, Even mainstream dieticians now conclude that dietary cholesterol is no longer a “nutrient of concern.” Why the change? Because it’s been proved wrong in study after study. The authors also point to the interesting case of Bolivian hunter-gatherers, the Tsimané, who have the lowest rate of heart disease in the world. Do they eat meat? You bet. Fifteen percent of their diet is meat in fact. Surely to have such low rates of heart disease should mean they eat no meat according to our vegan and vegetarian friends?
The obesity and meat connection is probably the weakest of all arguments. Here, our authors, point to a study form the American College of Nutrition that proved the benefits of high-protein diets when trying to lose weight. Most readers will know this from personal experience. I certainly do. I topped out at 225lbs on a conventional diet. I weigh 163 now.
The authors finish with a discussion of the mid-Victorians. I’m not going to go into this here, as I think it deserves its own post. Ultimately, our authors make a strong case that the war on meat is based on flimsy evidence. Though they don’t say it here, I think we can guess correctly that a lot of “scientists” who attack meat are not motivated by a search for truth. Otherwise, why do they ignore a body of evidence that puts their whole dietary world view in doubt? Why do they still cling to Ancel Keys and the McGovern Commission? This chapter is a good place to start if you need a defence against attacks on your lifestyle.