Monday, December 2, 2013

Powered By Plants: Natural Selection & Human Nutrition: NOW AVAILABLE

Well, more than two years of work has come to fruition.  I have finished Powered By Plants: Natural Selection & Human Nutrition.

In this extensively documented, 321 page e-book, including a 20 page bibliography and more than 800 footnotes, many including live links to the references, I present evidence supporting the hypothesis that a plant-based diet powered human evolution.

The first two chapters discuss the logical errors involved in taking fossil evidence, evolutionary hypotheses, and the fact that many humans do eat animals as "evidence" that humans are adapted to an animal-based diet and must eat animal flesh to maintain health and fitness.  The second chapter discusses in-depth the scientific meanings of the terms "carnivore" and "omnivore," and the logical errors involved in taking carnivorous behavior as evidence of biological adaptation to flesh-eating. This chapter also covers the nature of nutritional adaptations, using various illustrative examples from plant and animal evolution. 

Each of the Chapters 3 through 18 discusses one or more specific aspect of modern human anatomy, physiology, or metabolism in light of Darwinian evolutionary theory.  I present evidence that humans have heritable features primarily and specifically adapted to a plant-based diet, and lack the heritable features we would expect to find as evidence of specific adaptation to consumption of animal flesh.  I thoroughly discuss evidence casting doubt on claims that the features of our teeth and intestines provide evidence that our proposed stone-age African ancestors could not have obtained adequate energy, protein, or essential fatty acid intake from wild plants without eating flesh- and fat- rich diets.

The key Darwinian measure of adaptation consists of reproductive fitness.  Carnivores produce more viable offspring when eating animal-based diets than when eating plant-based diets; and animals biologically adapted to plant-based diets have their greatest fertility when eating plant-based diets.  Hence, the hypothesis that an animal-based diet powered human evolution predicts that animal-based diets promote and plant-based diets harm human fertility; while the hypothesis that a plant-based diet powered human evolution predicts that plant-based diets promote and animal-based diets impair human fertility.  Chapter 11 discusses extensively the evidence of the effect of animal- and plant- based diets on human reproductive function and Darwinian fitness.

The power of a hypothesis lies in its ability to explain or accommodate facts.  Given two hypotheses, the one that can explain and accommodate the largest body of evidence is the superior theory.  The two competing hypotheses concerning the role of foods in human evolution–the animal-based/hunting hypothesis, and the plant-based/cooking hypothesis–differ markedly in explanatory power.

For example, the hunting hypothesis predicts that humans will display a high tolerance for dietary cholesterol and saturated fats and that these promote health, not disease.  Hence,  this hypothesis can not easily explain the large body of independently accumulated evidence indicating that dietary cholesterol and saturated fats promote cardiovascular disease in humans, nor the evidence that the disease rarely occurs in populations eating plant-based diets.  Consequently, adherents get involved in trying to deny that body of evidence, or using ad hoc adjunct hypotheses (e.g. discussed in Chapter 18 of the book) to shore up the hunting hypothesis.  When a theory entails denying evidence independently accumulated in other relevant fields or requires ad hoc hypotheses for support, this usually means the theory is in crisis, as explained by Thomas Kuhn in The Structure of Scientific Revolutions.  In contrast, the plant-based/cooking hypothesis predicts that humans do not have a high tolerance for dietary cholesterol and saturated fats, despite having the ability to hunt, so it easily accommodates the independently produced evidence supporting the lipid hypothesis.

I have in this book presented what I believe to constitute convincing evidence that humans have a physiology primarily adapted by natural selection to a whole foods plant-based diet.  This evidence also indicates that humans lack many heritable adaptations to acquisition and chronic consumption of animal flesh that we find in other carnivores and omnivores.  Further, I also cite evidence that we have heritable characteristics specifically maladapted to flesh consumption.  I have spent more than two years gathering and organizing the literature in this one document.  I invite you to read the literature and judge for yourself.

Click on the cover to purchase your copy.  Table of contents below the image.

Table of Contents

Chapter 1:  The Stone Age Red Herring
Chapter 2:  The Nature of Nutritional Adaptations
Chapter 3:  Our Sensory Approach to Food
Chapter 4:  Locomotion
Chapter 5:  Manual endowments
Chapter 6:  Face, mouth, and throat
Chapter 7:  Stomach
Chapter 8:  Small Intestine
Chapter 9:  Cecum & Appendix
Chapter 10:  Colon
Chapter 11: Reproductive System
Chapter 12:  Protein Requirements
Chapter 13:  Vitamin C, Uricase, and Uric Acid
Chapter 14:  Complexion Preference
Chapter 15:  Carotenoids, Retinol, Cobalamin
Chapter 16:  Carbohydrate and Lipid Metabolism
Chapter 17:  Brain Size and Metabolism
Chapter 18:  Meat-Adaptive Genes?
Chapter 19:  Science, or Science Fiction?

Appendix A: Essential Nutrients
Appendix B: A Whole Foods Plant-Based Diet
Appendix C: Stone Age Hominins
Appendix D: Chimpanzees



Aspiring Steph said...

Wow! Looking forward to it after my exams!

Renaud said...

I bought your book. It's interesting, very dense, and evidently the result of hard work. But I have to say I didn't find it convincing.

First, your deep ideological bias shows on nearly every page, and that's very annoying to me. But you make very good and strong points proving we evolved on a plant based diet... which, anyway, is obvious to me. At least before the supposedly "high meat" paleo period. And I mostly agree to your debunking of this high meat myth.

But, in the end, I come back to the strong and pertinent point you make in the beginning of the book (the one I rely on to also ditch most of the paleo mythology) : biological adaptation is essentially a matter of survival and reaching reproductive age, and says nothing about the optimality of the diet for health and longevity.

I shall also mention your panda example... a carnivore eating a plant based diet ? So, why not a plant eater turning to (some) animal products ? Why would that necessarily be "bad" ? And I don't talk about going full 180° exclusive canivore (even if some are trying it and are still alive), as the panda did on the other direction.

I respect your ethical/ideological opinion, Don, but scientifically speaking you just showed that based on "evolution" veganism is no more (nor less) scientific than paleo.

And BTW I wholeheartedly agree on the idea of plant rich diet. But to me, to date, nothing prove that **some** animal product in the diet is more harmfull than beneficial (or even neutral).

tomR said...

How do you define a "plant based diet" in the caloric sense? Let's say is a diet based on 80% calories from plants and 20% of calories from animals a "plant based diet"?

Rex said...

Don, are you saying that humans should never eat any animal meat, milk or eggs at all? That all humans should be vegans? Or are you saying that animal foods should be limited below a certain threshold? There is a very big difference between those two positions in my opinion. Many people become deficient on a whole foods plant based vegan diet...I certainly did. I think the subjective experience of each individual is ultimately what matters most. Scientific research helps, but it cannot be the ultimate arbiter. I really, really wanted to eat a WFPB vegan diet because of all the scientific research in favor of it, and I gave it my best try...but it did not work for me. The problem was that every time I ate whole grains, I got indigestion. I couldn't get enough calories as a result and I lost a tremendous amount of weight (~14% of body mass). Now I eat mostly white basmati rice mixed with a variety of whole grains in a 2:1 or 3:1 ratio and I can get enough calories and not get indigestion in this way. I still tried to be vegan with that change in place and getting enough calories, but after a few months, I got gradually weaker, my physical stamina riding bicycles and lifting weights declined, and I was tired all the time. For protein I ate easily digestible and well-cooked legumes like red lentils, tofu, and tempeh, but these are still much much harder to digest for me than meat/milk/eggs. Now I am back to eating a variety of meats every day (I eat less in the spring and summer), and I have finally started to put on weight again, and I no longer feel tired and weak. I know you studied Chinese medicine, and I know that TCM says that animal meats are beneficial...Do you disagree with this? Don't you think everyone is a bit different and maybe some people need more concentrated nutrition than others? Do you believe in Ayurveda's classification of body constitutions such as vata, pitta, kapha?