So you want to eat healthy? No problem, just jump on the internet, check out a few health oriented diet websites and in no time you’ll get all the information you need! Oh . . . Uh . . . wait a minute, what’s all that confusing, contradictory information . . . ?
If you haven’t noticed, there’s a battle for your allegiance going on right now all over the internet and on the shelves of bookstores everywhere. If you’re not paying attention you may have missed it, but you’re being exposed to it all the time. It’s a battle about whether or not you should be eating meat.
Out of all the science and various good ideas about diet that have emerged in the last three decades, there are two camps who, at least for now, have become quite dominant in the national conversation about diet and health. Interestingly, at first glance, they appear to be almost diametrically opposed.
In one corner of the ring we have the “low carb” advocates, this would include followers of the Atkins diet, The South Beach diet, the Rosedale diet and the Paleo diet. In the other corner we have the vegans (i.e. no animal foods whatsoever). These would include followers of the ideas presented in the books “The China Study”, “Diet for a New America” and the documentary film “Forks over Knives”.
The Low carbers are well represented by the concept of the Paleo Diet, whose essential argument is that we should be eating the way our cave person (please take note of my political correctness) ancestors ate. The word Paleo comes from the term paleolithic, which refers to pre-agriculture humans, i.e cave people. Proponents of the Paleo diet recommend eating plenty of meat, poultry, fish, eggs, fresh vegetables, fruits, nuts and seeds. What is notably missing here are grains, legumes and dairy products. Thankfully, the modern Paleo diet doesn’t advocate eating grubs and insects, which I’m sure our hungry cave person ancestors ate when the circumstances dictated.
Vegans recommend eating a diet based entirely on plant foods: grains, legumes, vegetables, fruits, nuts, seeds and anything that is not part of, or does not come from an animal. What is missing here is meat, dairy and eggs.
The concept of veganism has been around for many years and was originally more associated with ethical and spiritual values, i.e. being kind to animals. In more recent years a strong stance has been taken amongst it’s proponents that it is the healthiest diet for humans, and that eating meat is associated with all sorts of health problems. The promotion of this idea comes largely from a few authors, most notably John Robbins, author of “Diet for a New America” and more recently by T. Collin Campbell and Thomas Campbell who wrote the very popular book “The China Study”.
So, what’s going on here? How can presumably intelligent and sincere health researchers come to such dramatically different conclusions? While I can’t answer that question definitively, I can give an educated hunch: bias and selective reporting.
One of the greatest pitfalls in research is looking selectively at the evidence. If you are doing research on the health effects of ice cream, for instance, and you really love ice cream and don’t want to stop eating it, you may find yourself searching out or giving more credence to evidence that makes positive assessments of ice cream (such as the study that suggests that regular ice cream consumption reduces osteoporosis in premenopausal women), and ignoring or giving less credence to evidence that ice cream isn’t good for you (such as the fact that you get congested and lethargic every time you eat it). This is easy to do, consciously or unconsciously, and I have found myself doing it when researching various health topics that I had an emotional investment in.
My sense is that authors on both sides of this debate are starting from an emotional or philosophical viewpoint and then consciously or unconsciously finding evidence to support their position while ignoring or minimizing evidence that contradicts it.
Weighing In on the Paleo Diet
The argument that we should eat the same pre-agricultural foods that our ancestors ate for millennia makes a certain amount of sense. Our bodies evolved, in part, in response to the foods that were available during prehistoric times and so are arguably better adapted to them. Indeed, in evolutionary terms, there has simply not been enough time since the advent of agriculture about 12,000 years ago for any appreciable change to our digestive or metabolic processes. There has certainly not been enough time to adapt to the dramatic changes to our diet brought on by the onset of industrialization 200 years ago.
There is, however, some inconvenient evidence that contradicts the core Paleo assumption. There are a number of populations around the world currently and historically who have enjoyed excellent health, a lower incidence of chronic diseases, extremely low rates of obesity and in some cases, increased longevity who consume grains as a daily part of their diet. This would suggest that it is not grains in and of themselves that are harmful to human health, at least not for all people.
And, while certain health parameters such as energy, blood sugar and cholesterol levels do reliably improve when transitioning from a standard Western diet to a Paleo type diet (we see this regularly in our clinic), many broader health claims are made by proponents of the diet for which there is really no hard evidence, such as reduced risk of heart disease, cancer and increased longevity. (I’m not saying that the Paleo diet does not have these effects, just that we don’t really know).
Weighing in on the Vegan Diet
Clearly there is something very appealing and noble about the idea of being able to sustain our health without causing suffering to other creatures. I can’t, and wouldn’t want to argue with that at all. The suggestion, however, that avoidance of all animal based foods is necessary, or even preferable to achieve optimal health is questionable, in my opinion.
When the book “The China Study” came out several years ago, I read it and was initially very impressed and convinced by the author’s essential arguments. T. Collin Campbell is a research scientist who did studies on mice given varying amounts of animal protein in their diets. He found that when mice ate more than 5% of their diet as animal protein (in the form of casein, an isolated protein from cow’s milk) their incidence of cancer increased, furthermore, their rates of cancer increased in proportion to the amount of casein in their diet.
He was later involved in epidemiological research in China comparing a more traditional Chinese diet which contains high amounts of plant based foods and very small amounts of animal based foods with a more modern western diet. It was found that rates of cancer and certain other diseases were lower in people eating a traditional Chinese diet. Dr. Campbell’s conclusion is that it is the percentage of animal based foods in the diet which are responsible for increased rates of cancer.
The more I thought about Dr. Campbell’s conclusions, the more I was bothered. Dr. Campbell’s argument begins with mice. While his results are compelling, research has shown over and over again that mice are not human! It is quite common, for instance, to see robust results in tests of therapeutic agents on mice or rats that do not later bear out in human studies. Furthermore, despite all the images we have seen in our lifetimes of mice eating cheese, casein is not the natural diet of mice! Mice in the wild primarily eat grains, seeds, berries and bugs.
Furthermore, people eating a traditional diet in China are more likely to be living in a rural environment and living a more traditional lifestyle overall. Individuals eating more meat and dairy products are likely to be urban dwellers. People in urban centers are often exposed to increased levels of stress, pollution, refined foods, loss of social support and disturbed sleep due to noise and light pollution. All of these may account for some of the differences in disease incidence that Dr. Campbell’s team found.
In addition, it is well documented that Inuit people (historically called eskimos) living on their traditional diet, which consists almost entirely of animal products, such as fish, seal, whale meat and blubber, have extremely low rates of cancer, even in recent times. When they adopt more western diets, their cancer rates and other disease rates increase proportionately. In a similar vein, Weston Price, the famous dentist who travelled around the world studying groups of unusually healthy people found that virtually all of them ate some meat, and some of them obtained a large percentage of their calories from dairy products.
What’s going on here?
To begin with, proponents of both the Paleo diet and the vegan diet generally advocate eating whole, unprocessed foods. If one is eating a standard American diet, making that change alone will undoubtedly bring some health benefits, and for some people it will bring dramatic health benefits. What is true for all humans is that prior to about 200 years ago we were eating diets that consisted primarily of whole, unrefined foods. Diets of unprocessed, natural foods are nutrient dense, high in fiber, and very low in potentially toxic substances which can impair or derange metabolism.
I do feel that both the vegan and Paleo camps are identifying real problems in our dietary landscape and offering some useful information. For me, the problem starts when a group of useful dietary principles are solidified into a block prescription for the entirety of humanity.
I have worked with a number of vegans (and vegetarians) who were sick specifically because their bodies could not maintain balance long term on a vegan or vegetarian diet. Virtually any naturopath can tell you stories about patients who’s health improved dramatically when they started including some animal products, particularly meat, poultry and fish, into their diet. Having said that, there are some people who seem to do very well on a vegan or vegetarian diet.
I have also worked with people on a low carb diet who were living on pork chops, bacon and all sorts of low carb specialty foods and were quite unhealthy. Dr. Atkins, who started the low carb movement had a heart attack later in life. Avoiding grains and carbohydrates does not, in and of itself, make a diet healthy.
Contributions from the Vegan Camp
The current vegan movement has made a number of important contributions. It has brought attention to ethical issues related to the treatment of animals. It has created a national conversation about the health implications of eating foods produced by modern farming methods.
Modern factory farms use massive feed lots where animals are fed a diet entirely unnatural to them (genetically modified corn) and kept in cramped quarters where they have to stand in their own manure and some of them are so sick that they can’t even stand on their own feet. This is not only inhumane but factory farming produces meat, poultry and fish that comes from unhealthy animals and is high in inflammatory compounds that are associated with increased risk of heart disease and cancer. Beef, lamb and buffalo raised entirely on grass do not have these problems.
Contributions from the Paleo Camp
Advocates of the Paleo diet and other low carb diets have highlighted the connection between excessive consumption of refined carbohydrates and a variety of health conditions, including obesity, hypertension and diabetes. In addition, the Paleo diet in specific has promoted a diet based in whole, unprocessed foods, something the father of all low carb diets, the Atkins diet, lacked.
Individuals need Individualized diets
The Paleo and vegan diet movements have focused on what category of foods we should eat. The problem with that is that we are all individuals and have different needs from each other, and different needs at different times of our lives. Using our intelligence, being sensitive to the feedback our bodies give us and adjusting our habits accordingly can help us find a diet that will nourish and nurture us. This, of course, will provide an internal environment that is conducive to healing.
I’m curious to hear from people: have you been on a vegan or low carb diet such as the Atkins, Southbeach or Paleo diets? How did you benefit from it? Did it have any negative effect on your health? Please leave a comment below.
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