I’ve been reading a lot about nutrition lately, as part of my program to age gracefully. I thought I was acquiring information that would help me preserve my good health, and I guess I was. But it turned out my real subject was how scientific blind spots—confirmation bias, foregone conclusions, beliefs that resist reality-testing—obscure the most valuable information. It’s hard to know whom to trust.
I began with a book that was highly touted as earth-shaking, starting with the title: The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-term Health. T. Colin Campbell’s (the author’s) scientific credentials are pretty impressive: Jacob Gould Schurman Professor Emeritus of Nutritional Biochemistry at Cornell University; the study was a 20-year collaboration with Cornell, Oxford and the Chinese Academy of Preventive Medicine. The book is crammed with detailed, closely footnoted descriptions of research supporting its conclusions, fully blurbed by Nobel laureates and the like.
So what are those conclusions? Dr. Campbell asserts that over-consumption of animal-based protein underlies almost all of the major diseases besetting Americans and others who eat like us. He says that by reducing our intake of animal protein to 5 percent or less of our total protein consumption, by instead following a plant-based diet rich in complex carbohydrates and colorful fruits and vegetables, we will virtually eliminate our susceptibility to cancers and heart ailments most common in the West.
What’s more, his entire story is framed by scientific and health authorities’ suppression of the relevant research and their compliant surrender to meat and dairy lobbies and those they’ve funded to legitimate their claims to dietary superiority. Campbell seems to be one of those characters who moved through life rising easily, and therefore expected to be treated fairly by the scientific establishment. The shock at what he found instead permeates every page.
I was totally convinced. I stocked my pantry with all sorts of whole grains, soy products and the like. I love to cook, so over the nearly three months we’ve tried this, I had great fun retooling all sorts of recipes for a vegan diet. Truly, when it comes to the aesthetics of eating, neither my husband or myself missed a thing.
There’s only one hitch: both of us have gained weight, my husband more than I, but I’ve put on enough to set off alarm bells. So a few weeks ago, we decided to cut our consumption: we must eating too many snacks or something, we reasoned, we must be having too much fun experimenting with new recipes. My husband’s metabolism has always been the type most irritating to the female of the species: if he noticed his belt was getting a little tight, he’d just skip his midnight snack for a few days and any extra poundage would slide right off. Only this time it didn’t. This time, he ate far less than any calculation would say his body needs to maintain, and nothing happened. I needed another book.
Good Calories, Bad Calories caught my eye. It’s written by a well-respected science journalist, Gary Taubes. A lot of it reads more like a textbook than a best-seller, evidently because, like Campbell, Taubes believes that grounding his book in research is the best way to support his theses. Taubes does not set himself up as a diet guru, despite the book’s title—there isn’t a single meal plan or recipe in the 450-page-plus volume. Instead, he painstakingly shows how countless scientific studies have disproved some of the pet theories of the scientific establishment, yet this well-documented countervailing work has had no impact on the certainties asserted by scientific and health authorities—to the contrary, it’s been actively suppressed.
Along the way, Taubes shows how some of the most treasured medical truths of our time have long been proven falsehoods: there isn’t any proven causal relationship between cholesterol and heart disease, for instance; nor has fat consumption been proven to cause breast cancer; nor has fiber been shown to have any preventive effect on colon cancer. Taubes shows how these false ideas were picked up by influential people, how circumstance, ambition and resistance to questioning scientific pieties gave them the ring of truth and a life of their own. Consumption of refined carbohydrates, on the other hand, has been shown to be directly causative of a whole string of diseases that tend to proceed in sequence: diabetes, heart, cancer… And for the same reasons, that information has not been given the attention and research it warrants. The documentation is there, chapter and verse, so before you reply that so many trustworthy authorities have reached the opposite conclusion, check it out.
Taubes’ overall point is that extensive double-blind studies of diet are needed to definitively establish relationships between things like fat, fiber, carbohydrates and disease. In the meantime, his explorations of weight reduction convinced me that my husband and I had put on weight because going vegan radically shifted the balance of carbohydrates in our diet. He cites study after study in which the orthodoxies of calorie reduction are disproven (including some in which animal and human subjects gain weight on less food, as their bodies compensate for changing insulin levels); and numerous studies in which high-protein, high-fat and low-carbohydrate diets resulted in weight loss, regardless of caloric intake.
So, it turns out that following the first book’s advice caused our problem: you see, animal protein is pretty much protein and fat, while all the vegan sources of protein (soy, seitan, legumes, etc.) also contain carbohydrates. Trying to get enough protein entailed a proportion of carbohydrates sufficient to push our bodies into fat-storage mode. So we’re reintroducing animal products for a while to take off the weight, and then, I expect, returning to a dietary regime that incorporates a sustainable proportion of non-animal protein, keeping our carbohydrates relatively low. I don’t expect we’ll be vegan again, and I worry that the life-extension benefits of The China Study will be diminished as a result. (Unfortunely, Taubes’ book didn’t focus on the health impact of animal protein and Campbell’s didn’t focus on excess carbohydrate consumption, so it will have to wait for another book to see if there’s a better way to reconcile the two.) But I feel better now, and that matters a lot.
All the time I was reading these books, here’s what I was thinking: both books’ treated questions that can be answered by close application of the scientific method, fair and rigorous testing over time on a reasonable scale, without any interference by funders or researchers whose agendas might skew the results. Yet in both cases, there was active opposition to the needed research and suppression of studies that hinted at results that could upset the heavily defended consensus. I consider myself an informed consumer of health information, yet if prior to reading either book you had tested me on the basic causes of heart disease, obesity and so on, I would have produced a string of wrong (if widely accepted) answers.
How much more so with conventional assertions about war, poverty, social exclusion, race, education, culture—you name it? In a funny way, these books strengthened my resolve to question orthodoxies and foregone conclusions wherever I find them. The world is full of reminders of the value of keeping one’s mind uncolonized by received opinion, of keeping one’s eyes open so long as we draw breath.
Very well done! I enjoyed reading your commentary. As you have further questions about the efficacy of animal products, I suggest you read “Nutrition Against Disease” by Roger J. Williams.
About 12 years ago I made a graph depicting the lifespans of presidents of the United States. To simplify things, I averaged their ages at time of death in groups of five (or four if an assassination occurred). It turns out to be a u-shaped curve. The first five presidents lived an average of 79. 6 years. At the beginning of the 20th century the average lifespan was 60.2 years – almost a 20 year drop. Our recent president’s longevities have brought the curve back up where it nearly matches the first five.
You know those first five presidents did not have access to good quality medical care. In fact, George Washington was likely killed by his physician’s choice of treatment. So what does this have to do with the above discussion? Well, I’m just pointing out that sugar and refined flour consumption rose steadily throughout the 19th century with a concurrent decline in mental and physical health. I mention mental health because it wasn’t until the assassination of our 16th president that any president died at the hand of a possibly mentally unstable individual. After Lincoln’s death there were assassinations or assassination attempts every 20 years or so like clockwork.
So your point regarding conventional assertions, orthodoxies, and forgone conclusions is well taken. Thanks.
Yes, well done and important. My wife and I happily discovered vegetarian cuisine in 1970 and it took us on a 37 year adventure in writing vegetarain cookbooks. I hope you will take a look at them – there is so much more interesting cuisine than meat-based dishes.
Please forgive my ignorance, for am I not nearly as well read (or practiced) as you are on matters of nutrition, etc. So, instead, I’ll pose a rather long-winded question.
A few years back, I found myself in the middle of a heated argument amongst friends regarding the values of a vegan lifestyle. I have always been an advocate, on a political and environmental level, for choosing not to eat meat and dairy products, as it does seem to matter what food industries we support. But as a weekend athlete (cycling, hiking), I also appreciate a boiled egg or chicken breast every now and then, and precisely for the energy it provides (protein, fat, etc.). So, I was pretty much a passive audience in the debate, and to this day I can’t absolutely identify with one position or the other. Those kinds of dualisms get boring, and quick.
However, at one point, one of my good friends said something very interesting, and it is an idea that has stuck with me ’til now. He claimed that Veganism, as it were, is problematic because it is not really a viable nutritional alternative for the vast majority of people around the globe. He further suggested that in many cultures worldwide animal-based protein sources are not a choice but an historical and physical necessity, and the benefits of a fruit and veggie diet can only be exploited in developed countries where nutritional (and culinary) plurality has already been established through the generations. Essentially, he believes we westerners (from a European background especially) contemplate and engage in vegan diets because biologically and physically we are able to do so–we are capable of such diverse changes to our system–whereas the same cannot be said about folks in other parts of the world who have entirely different bodies, histories, and natural environments.
Again, I’m no expert on these matters, but this seems like a valid opinion and a perspective that speaks to my personal experience with dietary effects. For example, I used to live in Tucson, Arizona, which sits just to the east of the Tohono O’odham native-American reservation. It is common knowledge in the American southwest that the Tohono O’odham community is currently suffering from almost epidemic rates of obesity, and subsequent health ailments thereof (heart disease, acne, etc.).
This has become a serious problem that has many causes, of course, but the most obvious and immediate is their radical change in diet in the last century. The Tohono O’odham have gone from a primarily desert meat (venison) and desert veggie diet (cactus buds, etc.), to a high-sugar and high-fat, European diet (tragically, this often means fast-food). I have included this link for your review:
Here’s my question: is it possible that the premise of the two books you mentioned, though sincerely articulated both, are nonetheless biased towards a specifically European biological system? Is it possible that bio-regionalism and personal ancestry play a much larger role in determining the most beneficial diet for any given individual? Perhaps meat or no meat debates are simplistic in that they don’t consider the cell-level differences between humans? Is there any mention of similar studies in the developing world?
My wife is Chinese. I’m a southern, white boy from the States. We can’t ever seem to find a suitable diet that meets both of our needs, and we’re beginning to think that we may have to dine separately from here on out. At this point (and beyond the obvious gender distinctions), my only working hypothesis is that we’re just built differently. Hopefully, I’m wrong and we’ll hit on something soon, but if I have to eat one more pork dumpling…
Anyway, thank you for your post, and any insight you might provide regarding my question. I enjoy your blog quite a bit, actually. It was first brought to my attention from a professor at the Victorian College of the Arts, a school at which I will be pursuing my Master’s in Community Cultural Development starting this winter. I am so syked, therefore, to have been given this link! Great stuff!
I’ll be watching/reading, respectfully, from afar. Thanks for your time.
I can’t buy your book in Shanghai yet, so it’ll have to wait until January. I look forward to the read…
Best book I’ve read on Nutrition (and I am a nutrition head) is Thrive by Brendan Brazier. Another good source would be Dr. Gabriel Cousens. Dr. Cousens approaches nutrition holistically – many of his book deal with the connection between nutrition and spirituality as well as emotional well-being. To keep the field balanced after reading Dr. Cousens it would be a good idea to read Dr. Douglas Graham at http://www.foodnsport.com
Ultimately only our bodies can tell us what is best. We are all unique. Our needs change and we need to remain flexible and open enough to roll with the changes.