Paleolithic diet

From Wikipedia, the free encyclopedia

The Paleolithic diet, also known as the caveman diet, paleodiet, Pangaian diet, Stone Age diet, the preagricultural diet, or hunter-gatherer diet, is the diet of wild plants and animals that various human species (see Homo (genus)) habitually consumed during the Paleolithic period (the Old Stone Age), a period of about 2 million years duration, ending about 10,000 years ago, when our species, Homo sapiens sapiens, invented agriculture. The modern version of this diet, the Paleolithic Diet, uses domesticated sources in lieu of the wild sources of the original hunter-gatherer diet.

Those who advocate that contemporary humans should regularly consume a Paleolithic diet base their advocacy on the premise that natural selection had 2 million or more years to genetically adapt the metabolism and physiology of the various human species to such a diet, and that in the 10,000 years since the invention of agriculture and its consequent major change in the human diet, natural selection has had too little time to make the optimal genetic adaptations to the new diet. According to those advocates, physiological and metabolic maladaptations result from those suboptimal genetic adaptations, which in turn contribute to many of the so-called diseases of civilization.^[1]

Those considerations give rise to a simple theme for adhering to a Paleolithic-type diet in modern times: if a food item resembles one that can be found in the wild, obtained with bare hands or simple tools, and ingested immediately without cooking, processing, and by simple preparation (i.e., peeling, cracking, washing, etc.), and cause the consumer no ill effects either during or after consumption, then it can be considered edible, and therefore permissible to eat. Any food meeting this standard can then be cooked and prepared by the simplest means as practical and consumed in modest quantities. Food exclusions comprise those introduced in the human food supply late in the course of human evolution, in particular after the invention of agriculture about 10,000 years ago: cereal grains, legumes and dairy products.^[2]

Contents 1 Overview 2 History 2.1 History of the human diet 2.2 History of this theory 3 Practices 3.1 Foods in the diet 3.2 Foods not in the diet 3.3 Intake 4 Food sources and preparation 5 Benefits 6 Support 7 Criticism 8 Cautions About Poisoning 9 Paleolithic Diet for Animals 10 References 11 Further reading 12 See also 12.1 Related info 12.2 Other related diets 13 External links

[edit] Overview

Supporters of this theory argue that human genetics have scarcely changed since the Stone Age, and therefore that an ideal diet would be a reconstructed Stone Age diet such as the one humans and proto-humans used before the Neolithic Revolution. Therefore through studying archeology and modern hunter-gatherers it could be determined what a healthy diet would comprise. Interest in Paleolithic nutrition has grown in recent years as low-carbohydrate diets have become more popular, as the two practices have, by coincidence not design, certain similarities.

This dietary concept is concerned primarily with health issues, as opposed to ethical or economic concerns. Advocates of the Paleolithic Diet believe that the best foods for the human body are those that humans are best adapted to eat, arguing that many modern ailments are diet related and can be avoided using the Paleodiet approach.

[edit] History

[edit] History of the human diet

Contributions are needed for this section

[edit] History of this theory

One of the first suggestions that following a diet similar to that of the late Paleolithic area would improve a person's health was made in the New England Journal of Medicine in 1985.^[3] This was followed up by a book, The Paleolithic Prescription,^[4] which focused on achieving the same proportions of nutrients (fat, protein, and carbohydrates, as well as vitamins and minerals) as were present in the diet of late Paleolithic people, not on excluding foods that were not available before the development of agriculture. As such, this early version of the Paleolithic diet recommended such foods as skimmed milk, whole grain bread, brown rice, and potatoes prepared without fat, on the argument that such foods have the same nutritional properties as Paleolithic foods.

More recent versions of the Paleolithic diet, such as NeanderThin^[5] and The Paleo Diet,^[6] focus on eliminating all foods that were not available to human beings in Paleolithic times, such as milk, dairy products, and grains.

[edit] Practices

[edit] Foods in the diet

Foods which are included in the diet are ones that can be obtained by using Paleolithic tools and practices, like meat (preferably game, though many followers of the diet eat farmed meat for practical reasons), fish, and gathered or foraged fruits, leaves, and roots of plants, mushrooms, nuts, eggs, and honey.

Some practitioners allow the use of oils derived from those foods which can be obtained and produced through Paleolithic means and are edible in their natural, uncooked state. Examples could include sesame oil and safflower oil, olive oil, but not oils derived from beans (for example, peanut oil) or grains (for example, corn oil). Others avoid the use of any oil, as it is a processed food.

The non-animal foods available in the diet are the same as those available in raw veganism. However, there are two fundamental differences between raw veganism and the Paleolithic diet: Firstly, practitioners consume meat and other animal products (in fact usually more is consumed than on a standard modern diet, in some cases substantially more). Secondly, any and all food may be cooked if desired.

[edit] Foods not in the diet

Vegetable foods which are not edible raw and unprocessed are excluded from the diet. The foods falling into this category are mainly grains (wheat, corn, rice, etc.), starchy vegetables (i.e., beans, and potatoes), certain fruits and nuts (e.g. cashews), and refined sugars. Alcoholic beverages are generally excluded because fermentation is also a form of processing, although some Paleolithic eaters allow certain exceptions (i.e., wine, since fermented (over-ripe) fruit can be found and consumed in small quantities with little ill effect). Dairy products are excluded despite being edible raw, since they cannot be found or consumed easily in nature, at least in any considerable quantity, and are consequently a post-agricultural food.

[edit] Intake

The generally prescribed proportions of protein, fat, and carbohydrate are approximately 20-35%, 30-60%, and 20-35% respectively by calories. By calories the diet is commonly around 45-65% animal products and 35-55% plant products. Alternatively, because of the large amount of water in fruits and vegetables, the diet is, by weight, roughly 2/3 plant products and 1/3 animal products.

Consequently, because of the high water content of fruits and vegetables, it is generally accepted that slightly less non-food water is required for optimal health. This is also supported by the fact that fresh water is not always readily available in the wild and that humans must rely on other sources for their water needs. This is not a reduction in need for water, but a shift in where water can be obtained.

The vitamin and mineral content of the diet is very high compared to a standard diet, in many cases a multiple of the RDA.

[edit] Food sources and preparation

For many practitioners of Paleolithic nutrition, the foods' source is just as important as the kind of foods being consumed. It is common practice to obtain Paleolithic foods from as natural a source as possible. Farmed meats, especially those organically farmed, are available from many natural sources, from free range poultry to grass fed beef, with many proponents preferring, though not as practical, wild game meats like quail, rabbit, and venison.

It is common practice among Paleolithic eaters that when cooking, unconventional cooking means should be avoided, such as the use of microwave ovens, and that foods are cooked just enough to kill any harmful bacteria that may be present.

Modern-day practitioners of the Paleolithic diet must be careful to get necessary nutrients found in foods that are not on the diet. For example, milk and other dairy products are a major source of calcium and vitamin D for most people following the conventional Western diet. Late Paleolithic people probably got sufficient calcium from wild vegetables and from gnawing the bones of animals they ate.^[4] Vitamin D can be synthesized by the body upon sufficient exposure to sunlight, and can be obtained from cod liver oil, and from oily fish such as salmon, mackerel, sardines, and tuna.^[7] Since cultivated vegetables have less calcium than their wild counterparts, since excessive exposure to sunlight has been linked to skin cancer, and since it can be expensive to eat fish several times a week, many followers of the diet may choose to take calcium and vitamin D supplements to be sure they get enough of these nutrients.

[edit] Benefits

The benefits of a Paleolithic diet are, as with most dietetic theories, widely debated.

There are however a number of medically diagnosed conditions whose sufferers have been shown to benefit directly from specific components of the diet. Some examples of this include:

• Coeliac disease, a gastrointestinal disorder whose sufferers are unable to digest the protein gluten, found in wheat.^[8]
• Dermatitis herpetiformis, a skin disorder linked also to digestibility issues related to gluten.
• Gluten ataxia, a common neurological manifestation of gluten sensitivity.^[9]
• Other conditions linked anecdotally,^[10] albeit unproven, to gluten and/or casein proteins include
  • Multiple sclerosis
  • Parkinson's disease
  • Rheumatoid arthritis^[11]
  • Schizophrenia
  • Tourette syndrome
  • Chronic fatigue syndrome
  • Attention deficit disorder
  • Autism

Other key health benefits commonly associated with and supported by this theory include:

• Reduction or elimination of grains, dairy, and refined sugars in the human diet has shown to lower glycemic load. This is thought to lower risk of diabetes and other related syndrome X diseases by placing less stress on the pancreas to produce insulin, and preventing insulin sensitivity.
• Increasing intake of fruits and vegetables induces a net base load, as opposed to the net acidic load on the body when eating a grain based diet. This is believed to prevent osteoporosis by passing less calcium salts through the kidneys.
• Animals that have been fed a pastural diet (free-range beef and chicken) instead of grain fed animals tend to have higher ratios of omega-3 fatty acids and other nutrients.
• By reducing the intake of processed foods the sodium/potassium ratios in the body are more balanced.

[edit] Support

Phytic acid, a chemical present in grain, is a strong chelator of important minerals such as calcium, magnesium, iron, and zinc. It, in essence, 'binds up' these minerals, and since humans lack the digestive enzyme phytase required to break this bond, these important minerals are not bioavailable, contributing significantly to mineral deficiencies. This problem is increased when dietary mineral supplements are not available, such as in developing countries.

High reliance upon cereal grains is likely to yield a positive NEAP (NET ENDOGENOUS ACID PRODUCTION) that in turn could increase the risk for osteoporosis, and other diseases of acid/base imbalance.^[12][13]

A high consumption of cereal grains, even whole grains, is likely to result in a high glycemic load diet, which in turn increases the risk for Obesity, Diabetes and other diseases of the metabolic syndrome.^[14][15]

Lectins present in cereal grains and legumes have the potential to cause auto-immune diseases, like rheumathoid arthritis, by a process called molecular mimicry (similarity of structure shared by products of dissimilar genes).^[16][17][18]

Milk and dairy products were not consumed prior to the agricultural revolution, i.e. prior to the domestication of milk-producing animals.^[19] Mature lactose tolerance is perhaps the most recent evolutionary change in humans, a phenomenon unique to humanity; it evolved independently in several regions (as noted above), but is not a universal trait in modern man -- although fermented dairy goods tend to be more readily digestible than unfermented.

Dairy products have been very valuable historically (in post-Agricultural-Revolution times) as a cheap and reliable source of protein, particularly in Europe, the Middle East, and India, but they, especially those derived from cow's milk, are more or less correlated with a variety of health issues, including type 1 diabetes,^[20] prostate cancer,^[21] multiple sclerosis,^[22] and Crohn’s disease.^[23] They also don't always make life any easier for Type 2 diabetics: milk, yoghurt, and cottage cheese have low glycemic indices but are highly insulinotrophic, with an insulin index similar to that of white bread.^[24][25][26]

[edit] Criticism

This section does not cite its references or sources. Please help improve this article by introducing appropriate citations. (help, get involved!) Any unsourced material that has been or is likely to be challenged may be removed at any time. This article has been tagged since November 2006.

• Large-scale economic sustainability: The primary merit of the agricultural revolution was that it made large quantities of calories readily and cheaply available. The Paleolithic diet, in rejecting the changes of the agricultural revolution, necessarily reverts to a state of more expensive energy in smaller quantities available -- rejecting the energy provided by grains, starchy vegetables, and dairy goods, to say nothing of fortified foodstuffs (and, for that matter, probably also iodized salt). These foods are staples of the modern diet -- and especially the pre-modern diet, of countries not yet industrialized on the scale of the United States -- for a very good reason, and it is very dubious whether even contemporary technology could produce enough food to let all humanity return to the Paleolithic diet, at least without first returning to Paleolithic levels of population.
• High farming expenses: Together with the question of whether the Paleolithic diet could produce enough food for the world is the question of whether that food, when produced, would be anything less than ruinously expensive. All stock-raising is energy-inefficient, and free-range meat fed with the animals' normal foods (as opposed to maize) is particularly expensive to produce on a large scale; the vegetables preferred in the Paleolithic diet do not lend themselves especially well to large-scale farming; there are estimates^{[citation needed]} that a hundred million people living on fish would destroy the world's fisheries; between these three points, supported by the anecdotal evidence that the Paleolithic diet is largely an American phenomenon, we might conclude that at the very least, its adoption would reduce many people's discretionary income.
• High food storage expenses: Providing fresh food free of preservatives on a large scale would introduce logistical challenges that would increase costs to producers and retailers. The advantages gained by using foods that are designed for longevity in storage would be lost. These additional costs would make food less affordable, returning to the point above.
• Calcium: Unless one were to eat the bones of the meat, a Paleolithic diet would risk being low in calcium. Vegetables like broccoli may serve to provide some, but dairy products are the most intuitive and easiest source. However, in many East Asian and South-east Asian diets where dairy products are rare (and often looked on with disgust), fish and seafood is consumed as a source of calcium; some small fish, anchovies and sardines for example, have bones soft and small enough to chew. Although eating small fish with their bones is uncommon in Western cultures, it could work as a source of calcium. Also, calcium needs are reduced when the intake of base producing fruits and vegetables is high, and the intake of acid producing grains is low. (citation needed)
• Vitamin D: Vitamin D can be produced from cholesterol through exposure to sunlight, but this is impractical in contemporary times, given that most modern activity occurs indoors. It may also not be desirable, reliable, or safe. Milk is easily and frequently fortified with vitamin D; by omitting it and rejecting fortification of foods, those using the Paleolithic diet must rely on exposure to sunlight to avoid deficiency. Other sources for vitamin D do exist -- cod liver oil, for example -- but these are not well-known or readily available, and are rejected by the Paleolithic diet's more rigorous forms.
• Protein: Dairy, like meat, is an excellent source of complete protein, as an alternative to eating meat for obtaining all of humanity's essential amino acids. This is especially so in the case of whey protein isolate, removed from the much-maligned casein protein of milk. Such alternate protein sources may be useful for those trying to lower cholesterol, who want a faster flux of proteins for faster tissue repair, or who have trouble digesting meat (especially the raw or barely-cooked meat that the Paleolithic diet prefers). That animal milk is not equivalent to human milk only means that it won't work as the entirety of a human diet -- it is still viable as a part. Dairy goods also don't involve killing animals, a significant advantage for vegetarians, and even if an accessory to some health problems, they are hardly carcinogenic like some chemicals in red meat.

One criticism of the Paleolithic diet is that it is possible that the human body has indeed evolved to some extent since early man. Small changes in the human body could still have occurred within the time frame from early in the Paleolithic up until recent times. For example, populations that have had agriculture for a while, may have had the time to adapt to it, at least to a small extent (microevolution). One example is lactose intolerance. Although most modern humans retain the ancestral feature of not being able to digest the sugar lactose which is found in milk after weaning from their mother's milk, the populations (mostly Europeans, Arabs, Indians, and the Maasai) that raised animals for dairy, did indeed evolve the ability (lactose tolerance) to digest it. Since there could have been changes to our body design (albeit small ones) since the last Ice Age, it may not be true that what was good for the Stone Age humans is good for modern people. As a counterpoint, the ability to consume lactose is not a large genetic leap, as we are already adapted to consume human milk; i.e. milk is much less objectionable from an evolutionary perspective when contrasted with other foods that are disallowed.

[edit] Cautions About Poisoning

As the consumption of raw foods gains popularity, some unsafe foods have occasionally entered the human diet. It should be pointed out that it is generally accepted among the supporters of Paleolithic nutrition that while it is necessary to eat only those things that can be consumed raw, it is not necessary or advisable to eat those foods raw. Many foods can harbor dangerous pathogens, including, among other things, salmonella, norovirus, and Trichinella spiralis, many of which can have serious health consequences if not first killed by means of heating, i.e., cooking. For this reason, cooking is allowed of things that, under normal healthy circumstances, would not require cooking to be consumed (grains still being discounted).

The heating to an adequately high temperature of meat, poultry, and fish will normally destroy harmful bacteria and in worse cases parasite eggs (such as tapeworm). Raw eggs can also contain many harmful substances, most commonly salmonella. However, recent studies have shown that the level of salmonella infection found in commercial eggs is negligible.^[27]

[edit] Paleolithic Diet for Animals

Pet food diets such as the BARF Diet (Bones and Raw food) (Biologically Appropriate Raw Food) for dogs and Prey Model Diet for cats are directly analogous to the Paleolithic diet for humans. Proponents of raw feeding note that cats and dogs are carnivores that have evolved to survive on raw meats, bones, offal, and small amounts of leafy plants, and are concerned that modern commercial pet foods contain a high proportion of health compromising grains, salt and sugars.^[28]

[edit] References

[edit] Further reading

• Eades, Drs. Michael R. and Mary Dan (2000). The Protein Power Lifeplan: A New Comprehensive Blueprint for Optimal Health. New York: Warner Books. ISBN 0-446-52576-6.

• Cordain, L. (2005) The Paleo Diet for Athletes. Rodale Books.

• Audette, R. (2000) Neanderthin. Saint Martin's Press

• Ungar, P. (2006) Evolution of the Human Diet: The Known, the Unknown, and the Unknowable (Human Evolution S.). Oxford University Press Inc

• Simopoulos, A. (1999) World Review of Nutrition and Dietetics: Evolutionary Aspects of Nutrition and Health, Diet, Exercise, Genetics and Chronic Disease v. 84 (World Review of Nutrition and Dietetics S.). S Karger AG

[edit] See also

[edit] Related info

• Medical research related to low-carbohydrate diets
• Neolithic Revolution
• Natural selection

[edit] Other related diets

• Gluten-free diet
• Gluten-free, casein-free diet
• Best Bet Diet
• Blood type diet
• Candida control diet
• Fruitarianism
• Joel Fuhrman diet
• The G.A.R.D. Diet The Glutamate-Aspartate Restricted Diet is very similar to the Paleolithic diet
• Gerson diet
• Hunza diet
• Raw food diet
• Low-carbohydrate diet
• Organic food diet
• Natural Foods Diet
• No-Grain Diet
• Specific Carbohydrate Diet
• Bushmeat
• Zone diet has similar protein:fat:carbohydrate ratios
• The Optimal Diet

[edit] External links

• The Paleolithic Diet Page
• Beyond Vegetarianism
• The Paleobiotics Lab
• Palaeolithic Nutrition?
• Free discussion forum for Paleo diet and fitness