First, thanks for the kind comments about my book. You can read more about the Paleo Diet concept at my website: The Paleo Diet where all of my scientific papers on the topic can be downloaded for free as PDF files.

Needless to say, Sally Fallon's review is bothers me -- not from a personal basis, but rather because it attempts to cloud the real dietary issues for readers like yourself, who may not have a sufficient background to know what is factual and what is hype. Further, this review attempts to discredit a very powerful new scientific concept (evolutionary medicine) that is being used worldwide by scientists in a wide variety of disciplines to answer complex health questions.

I do not know Sally Fallon, but I suspect that she has "an axe to grind" because of a debate I had with her co-author, Mary Enig, on whether or not dietary saturated fats were healthful or harmful. My research group and I believe that the high amounts of dietary saturated fats in the western diet promote atherosclerosis because they down-regulate the LDL receptor (a concept for which the Nobel prize in medicine was awarded in 1984). We do not believe that dietary saturated fats are the sole or even main cause of atherosclerosis, but rather are a part of many dietary elements that promote heart disease. You can view this online debate which occurred a number of years ago at this website: http://listserv.icors.org/archives/paleodiet.html.

It is natural and healthy for scientists to disagree on scientific and medical issues as this is the process called "peer review" which ultimately moves science foreward. Unfortunately, the internet is not a peer reviewed forum, and literally anyone can say anything they care to say. As far as I am aware, Sally Fallon is not a scientist, nor has she ever submitted any of her ideas to the peer review process in scientific journals. Does this mean that Sally Fallon's ideas have no merit? No, they simply have not been adequately tested using the scientific method. All of the information I present in my book is substantiated by peer reviewed scientific articles that I have published, along with my research group or by other scientists from diverse fields.

Sally Fallon's review attempts to debunk the Paleo Diet concept by using a satirical tone in which she misleads the reader by taking information out of context and emphasizes specific points without examining the larger picture. The first paragraph of her review represents an example of this deliberately misleading prose. There is no doubt that hunter-gatherers ate the entire edible carcass of animals that were hunted and killed, and the fatty portions of the carcass were relished more than the lean muscle tissue. We have pointed this information out in many of our scientific papers. However, there are two key points that Fallon fails to mention.

The first is the total fat content of wild animal carcasses varies seasonally throughout the year in a cyclic waxing and waning manner. Studies of caribou over a 12 month period show that the total carcass (organs and all) fat by weight for 7 months of the year average less than 5%; for 9 months of the year it average less than 10%. For 3 months of the year total carcass fat falls between 11-17%. In contrast 99% of the beef in the U.S. is produced under fed lot conditions in which the animal is always slaughtered at the peak or highest body fat % which typically exceeds 30 % by weight. An animal that has a body fat of 5% by weight equals 34 % fat by energy, whereas an animal that has a body fat of 30 % by weight equals 85 % fat by energy. Hence the total fat content of feed-lot produced domesticated animals is not even remotely close to that of wild animals.

The second point of deception in Fallon's review revolves around the types of fats available in the total edible carcass of wild animals over a 12 month period. From our recent paper analyzing the fat content in the tissues of wild animals (see webpage for article), we have been able to show that the dominant fats (> 50% energy) in organs are polyunsaturated (PUFA) + monounsaturated (MUFA) fatty acids, whereas the dominant (>50% energy) fat in adipose tissue is saturated fat. Further, by employing allometric regressions that scale organ mass to tissue mass and then by analyzing the fat content and fatty acid composition of each organ, it is possible to calculate the total edible carcass fatty acid composition as it varies throughout the year. Our results (in press) show that for 9 months or more of the year, it would have been impossible to obtain >10% of the total carcass energy as saturated fats.

In my book, the Paleo Diet, it was not my objective to precisely and exactly imitate the dietary practices of our hunter-gatherer ancestors, but rather to synthesize a diet from commonly available modern foods that would emulate the nutritional characteristics of hunter-gatherer diets. Few modern people would be willing to eat brains, intestines, liver, kidney, gonads, lungs etc. Nor do few modern, westernized people have access to wild animal meat and organs on a year round basis. By removing skin and excess fat from domestic meats available at the supermarket and then by adding in healthful oils, it is possible to simulate the entire carcass fatty acid profiles of wild animals. Consumption of the fatty cuts of meat (chicken with skin, hamburger, beef ribs etc) on a year round basis is vastly at odds with the nutritional patterns of hunter-gatherers. It's not that they didn't want to eat fatty meats; it's just that a year round source did not exist. Hence, my recommendation to eat lean meats trimmed of visible fat along with healthful oils provides a diet with approximately 10% or less of total energy from saturated fats – a value that mimics values in hunter-gatherer diets. From our paper (Cordain L. The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24), you can examine in more detail the fat profile of modern diets based upon Stone Age food groups.

The second paragraph of Fallon's critique again represents a satirical ploy to invalidate the entire concept of evolutionary nutrition based upon irrelevant information. In the first place Paleolithic people (hominins living during the Old Stone Age – approximately 2.4 million years ago until 10,000 years ago) did not cook in pots as pottery was first produced ~9,000 years ago. Secondly, oil extraction from any plants is not known to have occurred until ~ 6,000 years ago. But again, even though Fallon is unaware of this information, it skirts the real issue. It is virtually economically impossible or culturally deplorable for most western people to eat the entire carcass of wild animals throughout the year. Consequently certain beneficial changes must be made to foods commonly available at the supermarket to achieve the general nutritional characteristics of pre-agricultural diets. The addition of canola oil to lean domestic meats increases the MUFA and n-3 concentrations of the entire meal so that it more closely resembles the fatty acid concentrations that are present when the entire carcass of a wild animal is consumed. The addition of various spices, lemon juice etc. improves the flavor of the meat and makes it more palatable. Although this combination of spices certainly would not have been available to historically studied hunter-gatherers, there is extensive ethnographic evidence to show that various spices and plant parts were components of Holocene hunter-gatherer diets. The addition of these spices in no way impairs the nutritional qualities of the diet and in fact may add many valuable phytochemicals and antioxidants.

In the typical western diet refined sugars comprise 16-18% of the total daily energy. Clearly, there are numerous health problems associated with this enormous intake of empty calories. However, for many people it is difficult to make sudden behavioral changes, particularly when it comes to comfort foods, such as highly sugared processed foods (ice cream, cake, cookies, candy etc). Although fruits would be a much better choice for taming the sweet tooth, diet sodas can help people to make this transition. We never have suggested that diet sodas were part of pre-agricultural diets, but neither were fatty meats, milk, butter, cheese, whole grain breads or the salted foods that Fallon so highly recommends.

The third paragraph of Fallon's diatribe becomes personal and insulting – not just for me for any educated person. I prefer to let the data and information speak for itself, regardless of a person's gender, racial background or academic affiliation. Information should not be accepted or rejected upon who generates it, but rather upon the merit and objectivity of the idea. I personally find it repulsive to prejudice an individual or person based upon personal issues or characteristics that are unrelated to the information being presented.

In the third paragraph of her review, Fallon once again mistakenly suggests that we indicated that hunter-gatherers ate low fat diets. This never has been the case. Apparently, she has not bothered to read our paper (Cordain L, Brand Miller J, Eaton SB, Mann N, Holt SHA, Speth JD. Plant to animal subsistence ratios and macronutrient energy estimations in world wide hunter-gatherer diets. Am J Clin Nutr 2000, 71:682-92) in which we say Our analysis showed that whenever and wherever it was ecologically possible, hunter-gatherers consumed high amounts (45-65% of energy) of animal food. And "the fat intake would be comparable or higher (28-58% energy) than values currently consumed in modern, industrialized societies."

Fallon brings up the notion of political correctness (pc) in her review. As scientists, we utilize the scientific method to form and test our hypotheses and let the chips fall where they will regardless of any pre-conceived notions. Although it may be politically correct to state that saturated fats are not necessarily healthful when consumed the high amounts in the typical U.S. diet, it is terribly politically incorrect to recommend limiting grains of any kind (whole or processed) or dairy products. Our dietary recommendations have no basis in political correctness, but rather reflect what the data indicates.

In Fallon's 4^th paragraph she completely misleads the reader by stating that: "He says that Paleolithic peoples had no carbohydrate foods like grains or starchy root foods – never mind reports of grains found in the fire ashes of some of the earliest human groups, or the widespread use of tubers among primitive peoples, usually fermented or slow cooked." This statement steps far beyond the bounds of truth. We go on record as stating that Pre-Agricultural people ate few or no grains, however we have never suggested that they did not eat tubers. Again, if Fallon would take the time to read our scientific papers, she would be aware of this. In our AJCN 2000 paper (Table 3) we show that tubers, roots and bulbs would have comprised 23.6 % of all the plant food consumed by the average hunter-gatherer. Grains are virtually indigestible unless the cell walls are broken via (grinding or milling) and the starch is gelatinized by cooking. Hence the appearance of stone grinding tools (mortar and pestle, saddle stones etc) heralds the widespread use of grains in hunter-gatherer societies. The first primitive grinding tools do not make their appearance anywhere in the world until the late Paleolithic (~15-20,000 years ago), and the first society known to have made wide scale use of grains were the Natufians who lived in the Levant ~13,000 years ago.

The next statement in this paragraph is highly objectionable, false and is totally ignorant of the actual data regarding the fatty acid composition of the tissue of wild animals. “He says that there isn't much fat in wild animals (did he check with any hunters while writing his book?) and that what fat these animals had was highly politically correct—low in “lethal” saturated fat and rich in monounsaturates and omega-3 fatty acids. Did he look up the fatty acid profile of buffalo fat while researching his book? Obviously not. If he had, it would have ruined his whole theory because buffalo fat is more saturated than beef fat.” Apparently, Fallon again has failed to do her homework. If she would take the time to read our paper (Cordain L, Watkins BA, Florant GL, Kehler M, Rogers L, Li Y. Fatty acid analysis of wild ruminant tissues: Evolutionary implications for reducing diet-related chronic disease. Eur J Clin Nutr, 2002; 56:181-191.) she would know that our conclusions are based upon hundreds of hours of painstaking analysis. I don't believe Fallon has ever analyzed the tissues of any wild animals – we have, and our scientific results are much different than her opinions.

Here's another completely false statement “And obviously he didn't check up on canola oil, which he recommends as a source of omega-3 fatty acids—because virtually all canola oil is deodorized, a process that gets rid of the omega-3s.” This statement shows how anyone can say anything on the internet with absolutely no systems of checks and balances that are normally provided by the peer review process in scientific publications. Any reader who wants to can access Medline (https://pubmed.ncbi.nlm.nih.gov/) and find numerous studies showing that canola oil contains about 10 % of it's total fatty acids as omega 3 fatty acids. Here are 2 citations (Dupont J et al. J Am Coll Nutr 1989;8:360-75; Ayorinde FO et al. Rapid Commun Mass Spectrom. 2000;14:608-15).

In regard to salt, Fallon again does the reader a disservice by not adequately presenting the data. The systematic mining, manufacture and transportation of salt have their origin in the Neolithic. Dragging and gathering salt from dry lakebeds is known to have taken place on Lake Yuncheng in the Northern Province of Shanxi, China by 6000 B.C. The earliest evidence for salt exploitation in Europe comes from salt mines at Cardona, Spain dating to 4200 - 3600 B.C. It is likely that Paleolithic or Holocene hunter-gatherers living in coastal areas may have dipped food in seawater or used dried seawater salt in a manner similar to nearly all Polynesian societies at the time of European contact However, the inland living Maori of New Zealand lost the salt habit, and most recently studied inland hunter-gatherers add no or little salt to their food on a daily basis. Further, there is no evidence that Paleolithic (2.5 million years ago until 10,000 years ago) people undertook salt extraction or took interest in inland salt deposits. Collectively, this evidence suggests that the high salt consumption (~ 10 g per day) in western societies has minimal or no evolutionary precedent in all hominin species prior to the Neolithic period.

Fallon's final paragraph represents opinion unsubstantiated by factual data. Again, if she would have taken the time to read our paper (Cordain L. The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24), she would have known that a modern Paleo Diet contains almost 8 times the RDA for vitamin A. Consequently, her statement that high protein diets lead to vitamin A deficiency is nonsense and completely untrue. Although hunter-gatherers did not consume dairy products, their bones were robust and resistant to fracture and rarely exhibited signs and symptoms of osteoporosis which is endemic in western populations. As we have outlined at my website as well as in the JANA paper and elsewhere, these people maintained strong bones because they were in calcium balance – meaning that calcium intake exceeded calcium losses in the urine. When the diet is net acid producing, calcium balance can be maintained at lower calcium intakes.

Our recommendation to rub flax oil on meat prior to cooking was based on information published by the Flax Council showing that no oxidation occurred to flaxseed when cooked at 662F for 60 min. Apparently, flax oil may respond differently than flaxseed for unknown reasons. Because of the new information we have rescinded our previous recommendation and suggest that flax oil be added after cooking (see website for more information).

Fallon wraps up with her diatribe by saying that we indicated diet sodas were part of hunter-gatherer diets. This statement is a ludicrous attempt to discredit our scientific work and the work of hundreds of dedicated scientists throughout the world who realize the value of evolutionary nutrition in treating multiple diseases of civilization. The most powerful and pervasive idea in all of biology is evolution through natural selection. It has only been in the last decade that this organizing template has been applied to nutrition and health. Great strides are now being made in understanding how clinically demonstrated principles underlying proper nutrition can be traced to our genome. Our genome was conditioned and shaped by environmental selective pressures that occurred long before the Agricultural Revolution. Since the appearance of our genus Homo, more than 2 million years ago, there have been at least hominin 100,000 generations. Since the Agricultural Revolution of 10,000 years ago there have been only 500 human generations. Our genome simply has had insufficient time to adapt to the foods ushered in during the Neolithic (fatty meats, dairy products, whole grains and salty foods).

Cordially,

Loren

Loren Cordain, Ph.D., Professor
Department of Health and Exercise Science
Colorado State University
Fort Collins, CO 80523