Paleolithic diet

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This article is about a type of diet. For information on the dietary practices of Paleolithic humans, see Paleolithic#Diet and nutrition.
Wild fruits represent an important feature of forager diets as do wild vegetables, below.

The paleolithic diet, also known as the paleo diet or caveman diet, is a diet based on the food humans' ancient ancestors might likely have eaten, such as meat, nuts and berries, and excludes food to which they had not yet become familiar, like dairy.

The diet is based on several premises. Proponents of the diet posit that during the Paleolithic era — a period lasting around 2.5 million years that ended about 10,000 years ago with the advent of agriculture and domestication of animals — humans evolved nutritional needs specific to the foods available at that time, and that the nutritional needs of modern humans remain best adapted to the diet of their Paleolithic ancestors. Proponents claim that human metabolism has been unable to adapt fast enough to handle many of the foods that have become available since the advent of agriculture. Thus, modern humans are said to be maladapted to eating foods such as grain, legumes, and dairy, and in particular the high-calorie processed foods that are a staple of most modern diets. Proponents claim that modern humans' inability to properly metabolize these comparatively new types of food has led to modern-day problems such as obesity, heart disease, and diabetes. They claim that followers of the Paleolithic diet may enjoy a longer, healthier, more active life.

Critics of the Paleolithic diet have raised a number of objections, including that paleolithic humans did eat grains and legumes,[1] that humans are much more nutritionally flexible than Paleolithic advocates claim, that Paleolithic humans were not genetically adapted to specific local diets, that the Paleolithic period was extremely long and saw a variety of forms of human sustenance, or that little is known for certain about what Paleolithic humans ate. At least one study suggests Neanderthal man and early modern humans ate primarily plant food.[2]

Terminology and etymology[edit]

The term Paleolithic (/ˌpliəˈlɪθɪk/) describes a cultural period circa 2 million BCE and 10,000 BCE 'characterized by the use of flint, stone, and bone tools, hunting, fishing, and the gathering of plant foods'.[3] The term was coined by archaeologist John Lubbock in 1865.[4] It derives from Greek: παλαιός, palaios, "old"; and λίθος, lithos, "stone", meaning "old age of the stone" or "Old Stone Age."[5][6]

The terms caveman diet and stone-age diet are also used,[7] with paleo diet by 2002.[8][9] Loren Cordain trademarked the term "Paleo Diet".[10]

History[edit]

The roots of the idea of a paleolithic diet can be traced to the work in the 1970s by gastroenterologist Walter Voegtlin.[8] The idea was later developed by Stanley Boyd Eaton and Melvin Konner, and popularized by Loren Cordain in his best-selling 2002 book, The Paleo Diet.[8][9]

In 2012 the paleolithic diet was described as being one of the "latest trends" in diets, based on the popularity of diet books about it;[11] in 2013 the diet was Google's most searched-for weight-loss method.[12] The diet is one of many fad diets that have been promoted in recent times, and draws on an appeal to nature and a narrative of conspiracy theories about how nutritional research, which does not support the paleo diet, is controlled by a malign food industry.[13]

Foods[edit]

Cordain has said the diet requires:[14]

Seeds such as walnuts are rich sources of protein and micronutrients
  • More protein and meat: Meat, seafood, and other animal products represent the staple foods of modern-day Paleo diets, since advocates claim protein constitutes 19-35% of the calories in hunter-gatherer diets.[15] The Centers for Disease Control and Prevention, the national public health institute of the United States, recommends that 10-35% of calories come from protein.[16] Advocates recommend, relative to modern diets, that the Paleolithic diet have moderate to higher fat intake dominated by monounsaturated and polyunsaturated fats and omega-3 fats, but avoiding trans fats, and omega-6 fats.[15]
  • Fewer carbohydrates: Non-starchy vegetables. The diet recommends the consumption of non-starchy fresh fruits and vegetables to provide 35-45 % daily calories and be the main source of carbohydrates.[15] According to the United States Department of Agriculture, the acceptable macronutrient distribution range for carbohydrates is 45 to 65 percent of total calories.[17] A typical modern diet gets a lot of carbohydrates from dairy products and grains, but these are excluded in the Paleolithic diet.
  • High fiber: High fiber intake not from grains, but from non-starchy vegetables and fruits.[15]

Exclusions[edit]

Food groups that advocates claim were rarely or never consumed by humans before the Neolithic agricultural revolution are excluded from the diet. These include:

Rationale and counter-arguments[edit]

Paleolithic carving of a mammoth. Hunting by humans may have been a factor in its extinction, causing resource scarcity which may in turn have contributed to the development of agriculture.

The rationale for the Paleolithic diet derives from evolutionary medicine,[19] specifically the evolutionary discordance hypothesis, which states that "many chronic diseases and degenerative conditions evident in modern Western populations have arisen because of a mismatch between Stone Age genes and recently adopted lifestyles."[20] Advocates of the modern Paleolithic diet, including Loren Cordain, take the evolutionary discordance hypothesis for granted, and form their dietary recommendations on its basis. They argue that modern humans should follow a diet that is as nutritionally close to that of their Paleolithic ancestors as possible.

However, the validity of the evolutionary discordance hypothesis has been brought into doubt by recent research.[21]

Adaptation[edit]

The following are claims which advocates of the paleodiet make. Paleolithic humans were genetically adapted to eating specifically those foods that were readily available to them in their local environments. These foods therefore shaped the nutritional needs of Paleolithic humans. The physiology and metabolism of modern humans have changed little, if at all, since the time of their Paleolithic ancestors.[22] The extreme changes in human diets due to the agricultural and industrial revolutions occurred over less than 200 years ago, which is not enough time for genetic adaptation.

By using applied Darwinian medicine, the use of modern evolutionary theory to understand health and disease, one can see that the human genome today was chosen by natural selection for the ancestral Paleolithic environment.[citation needed] Natural selection took time and the cultural and lifestyle changes to westernized culture occurred too quickly for the gene pool to evolve with the environmental changes.[23] Between 5,000 and 10,000 years ago the agricultural revolution brought about the replacement of certain uncultivated foods from the Paleolithic diet with grains and dairy.[24] The industrial revolution, in combination with the development of agriculture, brought about significant changes to the diet less than 200 years ago as well.[24] This revolution brought about crop manipulation, animal-rearing practices, and food processing, thus further changing the Westernized diet.[24] Both of these major instances occurred recently enough that the human genome did not have time to adapt to the changed environment. Alleles that were selected for or were neutral in the hunter-gatherer environment now promote diseases in modern environments and diets.[25] Some of the alleles selected for in the past had positive effects for survival and reproduction, but may cause health problems in the post-reproductive years.[23] Selection processes that were made in post agricultural alleles were due to pathogens in the environment, not diet, lifestyle, or environmental changes.[23]

Counter-argument 1[edit]

Studies of traditionally living populations show that humans can live healthily with a wide variety of diets. Humans have evolved to be flexible eaters.[26] Additionally, this flexibility in diet rather illustrates the resiliency with which humans have adapted to post-agricultural society. The assumption that humans have been entirely maladapted to these changes undermines this fact, as well as the fact that much more research needs to be done in regards to evolutionary changes in order to understand the actual harm or good done by the introduction of grains, processed foods, and dairy into the modern diet. Not all processed foods are a post agricultural introduction, there is evidence early humans processed plant food and possibly prepared flour 30,000 years ago.[27]

Lactose tolerance serves as a perfect example of how humans have adapted to the introduction of dairy, demonstrating one of the ways that humans have actually adapted to their environment rather than deteriorated from it. It must also be kept in mind that while the idea behind the Paleo diet is that humans should eat like human ancestors, humans will never be able to do so in today's society, as every species of plant and animal that humans consumed has completely evolved to fit the dietary needs of a much larger population that must be sustained in modern society. While the introduction of grains, dairy, and legumes has not necessarily been easy for the modern human, especially the Westernized one, it is safe to say that if humans could only survive in environments similar to that of their ancestors, then the society that humans have would not be in existence today.[28]

Historical diet[edit]

It is often argued that pre-agricultural foragers did not suffer from the diseases of affluence simply because they did not live long enough to develop them.[29] Based on the data from recent hunter-gatherer populations, it is estimated that at age 15, life expectancy was an additional 39 years, for a total age of 54.[30] At age 45, it is estimated that average life expectancy was an additional 19 years, for a total age of 64 years.[31][32] Food energy excess, relative to energy expended, rather than the consumption of specific foods may underlie the diseases of affluence. "The health concerns of the industrial world, where calorie-packed foods are readily available, stem not from deviations from a specific diet but from an imbalance between the energy humans consume and the energy humans spend."[33]

Counter-argument 2[edit]

The data for Cordain's book only came from six groups, mainly living in marginal habitats.[34] One of the studies was on the !Kung, whose diet was recorded for a single month,[35] and one was on the Eskimos.[36] Due to these limitations, the book has been criticized as painting an incomplete picture of what the diets of Paleolithic ancestors may have looked like.[34] It has been noted that the rationale for the diet does not take adequate account of the fact that, due to the pressures of artificial selection, most modern domesticated plants and animals differ drastically from their Paeleolithic ancestors, whose nutritional profiles often differed drastically from their modern counterparts. For example, wild almonds produce potentially fatal levels of cyanide, but this harmful poison has been bred out of domesticated varieties by artificial selection.

Brassica oleracea, an edible wild plant

Moreover, many vegetables like Broccoli "did not ... exist in the Paleolithic period".[37] Broccoli and many other genetically similar vegetables (like cabbage, cauliflower, kale, etc.) are in fact modern cultivars of the ancient species Brassica oleracea, a wild plant also known as wild mustard.

With regard to attempts to emulate the "ideal" diet, molecular biologist Marion Nestle argues that "knowledge of the relative proportions of animal and plant foods in the diets of early humans is circumstantial, incomplete, and debatable and there are insufficient data to identify the composition of a genetically determined optimal diet. The evidence related to Paleolithic diets is best interpreted as supporting the idea that diets based largely on plant foods promote health and longevity, at least under conditions of food abundance and physical activity".[38] Ideas about Paleolithic diet and nutrition are at best hypothetical.[39]

Trying to devise an ideal diet by studying contemporary hunter-gatherers is difficult because of the great disparities that exist, for example with the animal-derived calorie percentage ranging from 25% in the Gwi people of southern Africa to 99% in Alaskan Nunamiut.[40] Recommendations to restrict starchy vegetables may not be an accurate representation of the diet of relevant Paleolithic ancestors.[41]

Evolutionary biologist, Marlene Zuk is also critical, she stated.

Those who follow the [paleo] diet may be missing out on vital nutrients, and it is believed that could create long term health problems, in particular for adolescent girls who may be at risk of developing osteoporosis later in life as a result of not getting enough calcium. (Marlene Zuk, at the University of Minnesota[42]

Reception[edit]

The British Dietetic Association named the paleo diet as among the five worst celebrity-endorsed diets of 2015, saying it risks being "unbalanced, time consuming, [and] socially isolating" and so "a sure-fire way to develop nutrient deficiencies".[43]

David L. Katz and Stephanie Meller have written that the paleolithic diet presents a "scientific case" in part because of its anthropological basis, but that there is comparatively limited evidence supporting its health benefit over other popular contemporary diets.[44] According to S. Jay Olshansky and Bruce Carnes, "there is neither convincing evidence nor scientific logic to support the claim that adherence to a Paleolithic diet provides a longevity benefit."[45]

A ranking by U.S. News & World Report, involving a panel of experts, evaluated the diet based on factors including health, weight loss, and ease of following. In 2014, it tied for last place out of 32 with the Dukan Diet.[46]

There is no good evidence the paleo diet is effective in treating inflammatory bowel disease.[47]

See also[edit]

References[edit]

  1. ^ Henry, Amanda; Brooks, Alison; Piperno, Dolores (2014). "Plant foods and the dietary ecology of Neanderthals and early modern humans". Journal of Human Evolution 69: 44–54. doi:10.1016/j.jhevol.2013.12.014. PMID 24612646. 
  2. ^ Plant foods and the dietary ecology of Neanderthals and early modern humans
  3. ^ "Definition: Paleolithic". Collins. n.d. Retrieved 17 March 2015. 
  4. ^ Lubbock, John (1872). Pre-Historic Times, as Illustrated by Ancient Remains, and the Manners and Customs of Modern Savages. London, UK: Williams and Norgate. p. 75. ISBN 978-1421270395. 
  5. ^ "Definition: Lithic". Collins Dictionary. n.d. Retrieved 17 March 2015. 
  6. ^ "Defintion: Paleo". Collins. n.d. Retrieved 17 March 2015. 
  7. ^ Shariatmadari, David (22 October 2014). "What language tells us about the roots of the stone age diet". Guardian. Retrieved 17 March 2015. 
  8. ^ a b c Fitzgerald M (2014). Diet Cults: The Surprising Fallacy at the Core of Nutrition Fads and a Guide to Healthy Eating for the Rest of US. Pegasus Books. p. 38. ISBN 978-1-60598-595-4. 
  9. ^ a b "The modern take on the Paleo diet: is it grounded in science?". Environmental Nutrition (7). 2010. 
  10. ^ Lowe K (20 July 2014). "A dissenting view on the Paleo Diet". The Seattle Times. Retrieved 17 March 2015. 
  11. ^ Cunningham E (2012). "Are diets from paleolithic times relevant today?". J Acad Nutr Diet 112 (8): 1296. doi:10.1016/j.jand.2012.06.019. PMID 22818735. 
  12. ^ "Top diets review for 2014". NHS. Retrieved 2014-11-24. The paleo diet, also known as the caveman diet, was Google's most searched-for weight loss method in 2013. 
  13. ^ Hall H (2014). "Food myths: what science knows (and does not know) about diet and nutrition". Skeptic 19 (4). p. 10. Fad diets and "miracle" diet supplements promise to help us lose weight effortlessly. Different diet gurus offer a bewildering array of diets that promise to keep us healthy and make us live longer: vegan, Paleo, Mediterranean, low fat, low carb, raw food, gluten-free ... the list goes on.  (subscription required)
  14. ^ Cordain, Loren (2010). The Paleo diet Revised. Houghton Mifflin Harcourt. p. 10. ISBN 978-0470913024. 
  15. ^ a b c d "THE PALEO DIET PREMISE". The Paleo Diet. Retrieved 14 June 2014. 
  16. ^ "Protein". CDC. US Government. Retrieved 14 June 2014. 
  17. ^ "Carbohydrates". USDA. Retrieved 14 June 2014. 
  18. ^ Cordain, Loren. "ONE TEQUILA, TWO TEQUILA, THREE TEQUILA… PRIMAL!". Retrieved 14 June 2014. 
  19. ^ Konner M.; Eaton, S. Boyd (2010). "Paleolithic Nutrition: Twenty-Five Years Later". Nutrition in Clinical Practice 25 (6): 594–602. P. 594.
  20. ^ Elton, S (2008). "Environments, Adaptation, and Evolutionary Medicine: Should We be Eating a Stone Age Diet?". In S. Elton, P. O'Higgins (ed.), Medicine and Evolution: Current Applications, Future Prospects. Boca Raton, FL: CRC Press. P. 9. ISBN 978-1-4200-5134-6.
  21. ^ Turner, Bethany L; Thompson, Amanda L (August 2013). "Beyond the Paleolithic prescription: incorporating diversity and flexibility in the study of human diet evolution". Nutrition Reviews 71 (8): 501–510. doi:10.1111/nure.12039. PMID 23865796. 
  22. ^ Konner M.; Eaton, S. Boyd (2010). "Paleolithic Nutrition: Twenty-Five Years Later". Nutrition in Clinical Practice 25 (6): 594–602. Pp. 594–95.
  23. ^ a b c Carrera-Bastos, P., Fontes-Villalba, M., O’Keefe, J., Lindeberg, S., Cordain, L. 2011. The western diet and lifestyle and diseases of civilization. Research Reports in Clinical Cardiology. doi:10.2147/RRCC.S16919
  24. ^ a b c Ramsden, C.; Faurot, K.; Carrera-Bastos, P.; Cordain, L.; De Lorgeril, M.; Sperling, L. (2009). "Dietary Fat Quality and Coronary Heart Disease Prevention: A Unified Theory Based on Evolutionary, Historical, Global, and Modern Perspectives". Current Treatment Options in Cardiovascular Medicine 11 (4): 289–301. doi:10.1007/s11936-009-0030-8. PMID 19627662. 
  25. ^ Eaton, S. Boyd, Strassman, B., Nesse, R., Neel, J., Ewald, P., Williams, G., Weder, A., Lindeberg, S., Konner, M., Mysterud, I., Cordain, L. 2002. Evolutionary Health Promotion. Preventative Medicine. doi:10.1006/pmed.2001.0876 PMID 11817903
  26. ^ Leonard, William R. "Food for Thought: Dietary change was a driving force in human evolution". Scientific American. 
  27. ^ Thirty thousand-year-old evidence of plant food processing
  28. ^ http://www.scientificamerican.com/article/why-paleo-diet-half-baked-how-hunter-gatherer-really-eat/
  29. ^ Ungar, Peter S.; Grine, Frederick E.; & Teaford, Mark F. (October 2006). "Diet in Early Homo: A Review of the Evidence and a New Model of Adaptive Versatility" (PDF). Annual Review of Anthropology 35 (1): 209–228. doi:10.1146/annurev.anthro.35.081705.123153. 
  30. ^ Hillard Kaplan, Kim Hill, Jane Lancaster, and A. Magdalena Hurtado (2000). "A Theory of Human Life History Evolution: Diet, Intelligence and Longevity" (PDF). Evolutionary Anthropology 9 (4): 156–185. doi:10.1002/1520-6505(2000)9:4<156::AID-EVAN5>3.0.CO;2-7. Retrieved September 12, 2010. 
  31. ^ Gurven, Michael; Kaplan, Hillard (2007). "Longevity Among Hunter- Gatherers: A Cross-Cultural Examination". Population and Development Review 33 (2): 321–365. doi:10.1111/j.1728-4457.2007.00171.x. ISSN 0098-7921. 
  32. ^ Osborne, Daniel L.; Hames, Raymond (2014). "A life history perspective on skin cancer and the evolution of skin pigmentation". American Journal of Physical Anthropology 153 (1): 1–8. doi:10.1002/ajpa.22408. ISSN 0002-9483. PMID 24459698. 
  33. ^ Leonard, William R. (December 2002). "Food for thought: Dietary change was a driving force in human evolution" (PDF). Scientific American 287 (6): 106–15. PMID 12469653. 
  34. ^ a b Peter S. Ungar; Mark Franklyn Teaford (1 January 2002). Human Diet: Its Origin and Evolution. Greenwood Publishing Group. pp. 67–. ISBN 978-0-89789-736-5. 
  35. ^ Lee, Richard (1969). "Kung Bushmen Subsistence: An Input-Output Analysis". Contributions to Anthropology: Ecological Essays. Ottawa: National Museums of Canada (230): 73–94. 
  36. ^ Eaton, M.D., S. Boyd; Shostak, Marjorie; Konner, M.D., Ph.D., Melvin (1988). The Paleolithic Prescription: A Program of Diet and Exercise and a Design for Living. Harper and Row. p. 79. ISBN 978-0060916350. 
  37. ^ C. Warinner (2013), "Debunking the Paleo Diet", TEDxOU, 25 January 2013, https://www.youtube.com/watch?v=BMOjVYgYaG8, accessed 21 August 2014.
  38. ^ Nestle, Marion (March 2000). "Paleolithic diets: a sceptical view". Nutrition Bulletin 25 (1): 43–7. doi:10.1046/j.1467-3010.2000.00019.x. 
  39. ^ Milton, Katharine (2002). "Hunter-gatherer diets: wild foods signal relief from diseases of affluence (PDF)" (PDF). In Ungar, Peter S. & Teaford, Mark F. Human Diet: Its Origins and Evolution. Westport, CT: Bergin and Garvey. pp. 111–22. ISBN 0-89789-736-6. 
  40. ^ Kolbert, Elizabeth. "Flesh of Your Flesh", The New Yorker, November 9, 2009, accessed January 27, 2011.
  41. ^ Gibbons, Ann (September 2014). "The Evolution of Diet". National Geographic. Retrieved 2014-09-04. 
  42. ^ Scientists argue that the Paleo diet could be doing more harm than good, 'ignores basic biology'
  43. ^ "Top 5 Worst Celebrity Diets to Avoid in 2015". British Dietetic Association. 8 December 2014. Retrieved February 2015. An unbalanced, time consuming, socially isolating diet, which this could easily be, is a sure-fire way to develop nutrient deficiencies, which can compromise health and your relationship with food. 
  44. ^ Katz DL, Meller S (2014). "Can we say what diet is best for health?". Annu Rev Public Health 35: 83–103. doi:10.1146/annurev-publhealth-032013-182351. PMID 24641555. 
  45. ^ Olshansky, S. Jay; Carnes, Bruce A. (2001). The quest for immortality : science at the frontiers of aging. New York: Norton. p. 191. ISBN 978-0393323276. 
  46. ^ "Best Diets Overall". U.S.News & World Report. 2012. 
  47. ^ Hou JK, Lee D, Lewis J; Lee; Lewis (October 2014). "Diet and inflammatory bowel disease: review of patient-targeted recommendations". Clin. Gastroenterol. Hepatol. (Review) 12 (10): 1592–600. doi:10.1016/j.cgh.2013.09.063. PMC 4021001. PMID 24107394. Even less evidence exists for the efficacy of the SCD, FODMAP, or Paleo diets. Furthermore, the practicality of maintaining these interventions over long periods of time is doubtful. 

Further reading[edit]

External links[edit]