It’s a part of my paleo fantasy, it’s a part of my paleo dream

There are many fallacies that undergird alternative medicine, which evolved into “complementary and alternative medicine” (CAM), and for which the preferred term among its advocates is now “integrative medicine,” meant to imply the “best of both worlds.” If I had to pick one fallacy that rules above all among proponents of CAM/IM, it would have to be either the naturalistic fallacy (i.e., that if it’s natural—whatever that means—it must be better) or the fallacy of antiquity (i.e., that if it’s really old, it must be better). Of course, the two fallacies are not unrelated. In the minds of CAM proponents, old is more likely to have been based on nature, and the naturalistic fallacy often correlates with the fallacy of antiquity. Basically, it’s a rejection of modernity, and from it flow the interest in herbalism, various religious practices rebranded as treatments (thousands of years ago, medicine was religion and religion was medicine—the two were more or less one and physicians were often priests as well), and the all-consuming fear of “toxins,” in which it is thought that the products of modernity are poisoning us.

Yes, there is a definite belief underlying much of CAM that technology and pharmaceuticals are automatically bad and that “natural” must be better. Flowing from that belief is the belief that people were happier and much healthier in the preindustrial, preagricultural past, that cardiovascular disease was rare or nonexistent, and that cancer was seldom heard of. Of course, it’s hard not to note that cancer and heart disease are primarily diseases of aging, and life expectancy was so much lower back in the day that a much smaller percentage of the population lived to advanced ages than is the case today. Even so, an implicit assumption among many CAM advocates is that cardiovascular disease is largely a disease of modern lifestyle and diet and that, if modern humans could somehow mimic preindustrial or, according to some, even preagricultural, lifestyles, that cardiovascular disease could be avoided. Not infrequently, evolutionary and genomic arguments are invoked, claiming that the estimated 10,000 years since the dawn of human agriculture is not a sufficiently long period of time for us to have evolved to handle diets rich in grains and meats and that we are “genetically wired” to exist on a diet like those of our paleolithic hunter-gatherer ancestors. For instance, in 2004, James H. O’Keefe Jr, MD and Loren Cordain, PhD wrote an article in the Mayo Proceedings entitled Cardiovascular Disease Resulting From a Diet and Lifestyle at Odds With Our Paleolithic Genome: How to Become a 21st-Century Hunter-Gatherer that asserted in essence, just that. Over the last decade, Cordain has become the most prominent promoter of the so-called “Paleo diet,” having written The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat and multiple other books advocating a paleolithic-mimetic diet as the cure for what ails modern humans. Meanwhile, diets thought to reflect what our hunter-gatherer ancestors ate, such as the Paleo Diet consisting largely of animal and fish that can be hunted and fruits and vegetables that can be foraged for in the wild, have been promoted as a near-panacea for the chronic diseases of aging, such as cardiovascular disease and cancer.

But how does one determine what the prevalence of cardiovascular disease was in the ancient past? Time and the decomposition it brings are brutal on the flimsy meat of which we are made, and it is uncommon to have access to anything other than bones, much less bodies intact enough to be examined for signs of atherosclerotic disease. Even so, however, there have been indications that the idea that ancient humans didn’t suffer from atherosclerosis is a comforting myth, the most recent of which is a study published a week ago online in The Lancet by Prof. Randall C. Thompson of Saint Luke’s Mid America Heart Institute and an international team of investigators entitled Atherosclerosis across 4000 years of human history: the Horus study of four ancient populations. Basically, it was a study of 137 different mummies from four different geographic locations spanning 4,000 years. The areas spanned included ancient Egypt, ancient Peru, the Ancestral Puebloans of southwest America, and the Unangan of the Aleutian Islands.

The reason for the study is described in the introduction:

Human cultures residing in environments that are either very dry, hot, or cold have independently discovered how to mummify their dead. Thus, preindustrial or preagricultural cultures created the opportunity for a natural experiment—to study these ancient human beings with modern CT scanning to assess the extent of vascular calcifications in diverse environments and cultures. A common component of a mature atherosclerotic plaque, vascular calcification in modern day human beings is pathognomonic for atherosclerosis.4 Calcification consistent with atherosclerosis has been identified by CT scanning in the naturally mummified Iceman from present day Italy who lived around 3000 BCE (before common era).5 More than a century ago, Johann Nepomuk Czermak6 and Sir Marc Armand Ruffer7 gave serious evidence for atherosclerosis in several autopsies of Egyptian mummies from around 1000 BCE. Our recent studies confirmed these findings of atherosclerosis in 20 of 44 Egyptian mummies who lived during several dynasties between 1981 BCE and 364 CE (common era).8 and 9 However, ancient Egyptian culture and lifestyles might have had unique attributes relative to atherogenesis. Moreover, mummification in Egypt during the bulk of this time was primarily performed on elite Egyptians of high socioeconomic status.

So, although there was a fair amount of evidence from studies of Egyptian mummies that atherosclerosis was not uncommon, in Egypt it was mainly the wealthy and powerful who were mummified after their deaths. Conceivably, they could have lived a very different lifestyle and consumed a very different diet than the average Egyptian living around that time.

So the authors obtained whole-body CT scans of the 137 mummies, either pre-existing scans or scans prospectively done, and analyzed them for calcifications. The mummies to be included in the study were chosen primarily based on two factors, being in a good state of preservation with identifiable vascular tissue, and being adults. The authors obtained identifying information from an extensive search of museum and other databases by a team of archeologists and experts in mummy restoration, and sex was determined by either analysis of the genitals and reproductive organs when present and by pelvic morphology when they were not present. Age was estimated by standard analysis of architectural changes in the clavicle, femur, and humerus. Finally, multiple anthropological and archeological sources were used in an attempt to estimate likely risk factors for the mummies. Obviously, this last part involved a fair amount of inference and speculation, but that is to be expected in archeological studies.

Here are the findings:

Probable or definite atherosclerosis was noted in 47 (34%) of 137 mummies and in all four geographical populations: 29 (38%) of 76 ancient Egyptians, 13 (25%) of 51 ancient Peruvians, two (40%) of five Ancestral Puebloans, and three (60%) of five Unangan hunter gatherers (p=NS). Atherosclerosis was present in the aorta in 28 (20%) mummies, iliac or femoral arteries in 25 (18%), popliteal or tibial arteries in 25 (18%), carotid arteries in 17 (12%), and coronary arteries in six (4%). Of the five vascular beds examined, atherosclerosis was present in one to two beds in 34 (25%) mummies, in three to four beds in 11 (8%), and in all five vascular beds in two (1%). Age at time of death was positively correlated with atherosclerosis (mean age at death was 43 [SD 10] years for mummies with atherosclerosis vs 32 [15] years for those without; p<0·0001) and with the number of arterial beds involved (mean age was 32 [SD 15] years for mummies with no atherosclerosis, 42 [10] years for those with atherosclerosis in one or two beds, and 44 [8] years for those with atherosclerosis in three to five beds; p<0·0001).

Figure 2 summarizes the findings nicely:

athero graph

There’s also this video featured in a Nature report on the study showing the reconstructed scan of one of the mummies with atherosclerotic plaques in the coronary arteries.

As expected, more atherosclerosis correlates with advanced age, and the amount of atherosclerosis in the young and middle-aged (although the times in which the people who became these mummies after death lived age 50 was old) was less. Although the sample number was far too small to draw definitive conclusions (as is often the case in archeological research), the prevalence of atherosclerotic disease in these mummies did not appear to correlate with the cultures in which the mummies lived. As is noted in Thompson’s article, ancient Egyptians and Peruvians were agricultural cultures with farms and domesticated animals, Ancestral Puebloans were forager-farmers, and the Unangans were hunter-gatherers without agriculture. Indeed, the Peruvians and Ancestral Puebloans predated the written word and were thus prehistoric cultures. At least, there were not large differences to suggest that studying more mummies might yield a statistically significant difference. Certainly,this doesn’t rule out the possibility that there was a difference, but also certainly atherosclerosis was common even among hunter-gatherers.

One notes that no one, including the authors of this study, is saying that lifestyle and diet are not important factors for the development of atherosclerotic heart disease. What they are saying is that atherosclerosis appears to be associated with aging and that the claims that mimicking paleolithic diets (which, one notes, were definitely not vegan) are overblown. In other words, there is a certain inherent risk of atherosclerosis that is related to aging that is likely not possible to lower further, with the study concluding:

In conclusion, atherosclerosis was common in four preindustrial populations, including a preagricultural hunter-gatherer population, and across a wide span of human history. It remains prevalent in contemporary human beings. The presence of atherosclerosis in premodern human beings suggests that the disease is an inherent component of human ageing and not characteristic of any specific diet or lifestyle.

I actually think that the authors probably went too far with that last statement in that, while they might be correct that atherosclerosis is an inherent component of human aging, it is quite well established that this inherent component of aging can at least be worsened by sedentary lifestyle and probably certain diets. Professor Thompson provided a bit more nuance in a quote in an article for TIME Magazine:

We found that heart disease is a serial killer that has been stalking mankind for thousands of years. In the last century, atherosclerotic vascular disease has replaced infectious disease as the leading cause of death across the developed world. A common assumption is that the rise in levels of atherosclerosis is predominantly lifestyle-related, and that if modern humans could emulate pre-industrial or even pre-agricultural lifestyles, that atherosclerosis, or at least its clinical manifestations, would be avoided. Our findings seem to cast doubt on that assumption, and at the very least, we think they suggest that our understanding of the causes of atherosclerosis is incomplete, and that it might be somehow inherent to the process of human aging.

One notes that, although the Paleo Diet is not, strictly speaking, always sold as CAM/IM, the ideas behind it are popular among CAM advocates, and the diet is frequently included as part of “integrative medicine,” for example, here at the University of Connecticut website, where it’s under integrative nutrition. Indeed, take a look at this video:

One wonders how some of the cavewomen in this video managed to have big hair and lipstick. several thousand years ago.

A related site is called CaveMenMeds. Although it features rather strong support for the theory of evolution, unfortunately, it also misuses evolution in much the same way that Cordain has done (as discussed in this very post) and in parallel make the same sorts of fallacious arguments about placebo effects that we’ve discussed many times before here on SBM. Basically, it couples myths about how paleolithic humans lived with a typical “integrating” of ideas that range from the sensible to the pseudoscientific to discuss disease. This is just the most direct link between CAM and paleofantasies that I came across in my web wanderings. There are many more less direct links to be found.

In particular, the appeal to ancient wisdom and ancient civilizations as yet untouched by the evil of modernity is the same sort of arguments that are made in favor of various CAM modalities ranging from herbalism to vegan diets rebranded as being somehow CAM to the appeal to “natural” cures. Indeed, the fetish for the “natural” in CAM is such that even a treatment like Stanislaw Burzynski’s antineoplaston therapy is represented as “natural” when in fact, if it were ever shown to work against cancer, it would be chemotherapy and has toxicities greater than that of some of our current chemotherapy drugs.

All of this brings us to another article from about a week ago about a book that I think I need to read that talks about “paleofantasy” and “Stone Age delusions.” The book is by Marlene Zuk and entitled Paleofantasy: What Evolution Really Tells Us About Sex, Diet, and How We Live. Zuk is an evolutionary biologist, and in particular she points out how the evolutionary arguments favored by advocates of the Paleo diet don’t stand up to scrutiny.

The interview begins with Zuk confronting Cordain at a conference on evolution and diseases of modern environments. At his lecture, Cordain pronounced several foods to be the cause of fatal conditions in people carrying certain genes. These foods included, predictably, cultivated foods such as bread (made from grain), rice, and potatoes. Zuk couldn’t resist asking a question, namely why the inability to digest so many common foods would persist in the population, observing, “Surely it would have been selected out of the population.” Cordain’s response? That humans had not had time to adapt to these foods, to which Zuk retorted, “Plenty of time.” Apparently, in her book, Zuk produces numerous examples of evolution in humans occurring in a time frame of less than 10,000 years, including:

  • Blue eyes arose 6,000 to 10,000 years ago
  • Rapid selection for the CCR5-D gene variant that makes some people immune to HIV
  • Lactase persistence (production past the age of weening of the lactase enzyme that digests lactose in milk) probably dates back only around 7,500 to 10,000 years, around the time that cattle were domesticated

Zuk also points out, as Thompson did in the Lancet study of atherosclerosis in mummies, that there is no one diet or climate that predominated among our Paleolithic ancestors:

Zuk detects an unspoken, barely formed assumption that humanity essentially stopped evolving in the Stone Age and that our bodies are “stuck” in a state that was perfectly adapted to survive in the paleolithic environment. Sometimes you hear that the intervention of “culture” has halted the process of natural selection. This, “Paleofantasy” points out, flies in the face of facts. Living things are always and continuously in the process of adapting to the changing conditions of their environment, and the emergence of lactase persistence indicates that culture (in this case, the practice of keeping livestock for meat and hides) simply becomes another one of those conditions.

For this reason, generalizations about the typical hunter-gatherer lifestyle are spurious; it doesn’t exist. With respect to what people ate (especially how much meat), the only safe assumption was “whatever they could get,” something that to this day varies greatly depending on where they live. Recently, researchers discovered evidence that people in Europe were grinding and cooking grain (a paleo-diet bugaboo) as far back as 30,000 years ago, even if they weren’t actually cultivating it. “A strong body of evidence,” Zuk writes, “points to many changes in our genome since humans spread across the planet and developed agriculture, making it difficult at best to point to a single way of eating to which we were, and remain, best suited.”

Some advocates of “paleo” will claim that they are not at all advocating that humans should eat what their paleolithic ancestors ate but that we should use what they ate as a template to figure out what to eat today. That’s a distinction without a real difference because the assumptions upon which the Paleo Diet are based (e.g., that atherosclerosis didn’t exist in hunter-gatherers and that hunter-gatherers were “almost always healthy, lean, fit, disease-free, strong people” and that 10,000 years is too short a time period for humans to have evolved to accommodate a grain-based diet) are more the product of wishful thinking and the “noble savage” myth than anything else. At the very least, Thompson’s study suggests that this assumption is overblown and that there has long been a certain “baseline” level of atherosclerotic disease among humans that is an inevitable part of aging. Whether or not a “Paleo”-like diet can modulate that baseline risk factor downward or at least decrease the risk of people living in modern technological societies from what our current mosaic of genetics, lifestyle, diet, and environment produce is an open question, but we’re not off to a good start when the underlying premise is so questionable.

Oh, and, as Zuk tells us, paleolithic people got cancer, too.

Ever since the rise of science and industry, there has long been a significant proportion of the population who distrust, fear, and sometimes even loathe modernity. Science changes too fast; it is thought to endanger “spiritual matters”; it tramples on “traditional values.” People fantasize about and long for a (nonexistent) time long past, when humans supposedly lived in harmony with their environment, and view science, specifically for the purposes of this discussion modern biomedicine, has having participating in destroying that “ancient wisdom.” We see strains of this tendency not just in medicine and “integrative medicine” but in literature and many other areas as well. Films such as Avatar and Dances With Wolves, among many others, portray scientists and “Western” man as rapacious and ready to destroy a race of hunter-gatherers and early agrarian people who are portrayed as living in complete harmony with nature. CAM and the Paleo diet share this fear of modernity as an underlying assumption even as their advocates use and misuse evolution to “prove” their worth. This is nothing new, and the rationale behind the Paleo diet is nothing more than, as Zuk has put it, the evolutionary search for our perfect past. Unfortunately, fantasy is not reality, and we humans have long been known to abuse and despoil our environment, even back in those “paleo” days. Indeed, when I took a prehistoric archeology course, which was largely dedicated to the period of time of the hunter-gatherers, one thing I remember my professor pointing out, and that was that what he did was largely the study of prehistoric garbage and that humans have always produced a lot of it.

We still haven’t stopped, unfortunately.

Posted in: Evolution, History, Nutrition

Leave a Comment (160) ↓