Were there many Paleo Diets?

Miki Ben-Dor Department of Archaeology

Tel Aviv University, Israel AHS13

August 2013

The Chimp’s Diet has no starch, is low-mid carb, composed of 71% protein/fat and 29% sugars(Most fat arrive from fermentation of fiber by bacteria in a large colon)

Conklin-Brittain NL, Wrangham R, Smith CC (2002) A two-stage model of increased dietary quality in early hominid evolution: The role of fiber. In: Ungar PS, Teaford MF, editors. Human diet: Its origin and evolution: Greenwood

% weight (Conklin-Britten 2002)

% calories (Assuming 1.5 cal. fat/1 gr fiber)

Full explanation and references at http://www.paleostyle.com/?p=2001

Anatomy

Most non-domesticated plants are highly fibrous. Humans have a small colon and were therefore unable to extract significant energy from plants.

40% Smaller

Colon is 21% of a smaller gut, ¼ of Chimp colon, Little B12, max. 8% of energy

Colon is 52% of the gut,Source of fat and B12

Milton, K. (1999). Nutritional characteristics of wild primate foods: do the diets of our closest living relatives have lessons for us? Nutrition 15:488–498

Anatomy

Why the “Cooking Hypothesis” is not the answer to humans’ inability to process large amounts of fiber to energy

Wrangham proposed that cooking by Homo erectus 1.8 million years ago allowed humans to consume tubers despite their significant fiber content and humans smaller colon and teeth.

However:

◦ Archaeological evidence shows habitual control of fire only begin 1.4 million years later

◦ Genes that promote significant starch metabolism appear at the earliest only 1.6 million years later.

◦ Genes to cope with tubers’ low folic acid content and detoxification of tuber glycosides appear only recently and only among agricultural populations that consume domesticated tubers.

◦ Nitrogen Isotope studies confirm low plant consumption in the late Paleolithic even though cooking was well established.

◦ Meat and fat consumption offer more parsimonious solution to the fiber problem as they are energy dense and do not have fiber so do not require cooking to be metabolized.

Genetic study shows: adaptation to tubers consumption is only recent and limited to tuber consuming, agriculture populations

Genetic adaptation only in groups with post-Paleolithic consumption of tubers to:•Starch and sucrose metabolism•Folic acid biosynthesis•Detoxification of plant glycosides

Genetics

Starch feeding mouth bacteria (S. mutans) appeared only 10 thousands years ago indicating only recent significant consumption of starch

Microbiology

Many populations are still not adapted to consumption of large quantities of starch – large variation exists between humans in number of copies of the gene for salivary amylase (AMY1) that secures lower insulin for metabolism of starch sourced glucose

Genetics

Uneven Very recent?

Most Paleolithic sites contain almost exclusively animal bones and stone tools

Archaeology

Most stone tools were used for animal processing

Archaeology

In cases in which plants consumption becomes important, just prior to agriculture, the archaeological evidence is abundant and clear

Grinding tools, storage structure in sites dated to a period just before agriculture

Archaeology

Dental plaque analyses show that the Paleolithic diet did include plant food, however, this method can not determine relative quantities of meat/plant in the diet

Cooking technology and large animal extinction did not reduce recent Hunter Gatherers’ dependency on animal foods

81% 87% 80% 89% 61% 78% 29% 68% 26%? 54%Animal foods

Caloric percentage of animal food for groups who were systematically studied

Ethnography

N Isotope analysis, used to define level of animal protein consumption, is a very sensitive tool -Able to detect that Neolithic upper class consumed more meat than did the lower class

Isotopes

Isotopes

Humans

All isotopic studies confirm that Upper Paleolithic humans were top carnivores

Strontium and Barium analysis in human and animal teeth from approx. 2 MYA show: “Early Homo (is) indistinguishable

from carnivores” (Nature 2012)

Strontium

Africa 1.5 MYA - “The appearance of Homo is marked by a sharp drop in the number of large carnivores (>20 kgs) but not small carnivores”

Italy 0.5 MYA – Homo appear. Large carnivores drop despite increase in large herbivores.

Werdelin L, Lewis ME (2013) Temporal Change in Functional Richness and Evenness in the Eastern African Plio-Pleistocene Carnivoran Guild. PLoS ONE 8(3): e57944.

Large Carnivores Small CarnivoresHomo erectus

Paleontology

Signs of competition between early humans and large carnivores

6 of 6 food related behaviors were typical of humans and carnivores but not primates

“there is incontrovertible evidence of the convergence of human behavior with carnivore behavior”

Animal Behavior

Two carnivorous omnivores

Wolf (Canis)

Social Monogamy 2nd Widest geographic

distribution Endurance locomotion Prey size: 1000 kgs – 1 kg Preying on young and old

Homo

Social Monogamy Widest geographic

distribution Endurance locomotion Prey size: 6000 kgs - 1 kg Preying on adults

Animal Behavior

Joint venture?

“our findings highlight the emergence of carnivory as a process fundamentally determining human evolution.”

Weaning in humans 2-3 yearWeaning in Chimps 4-5 years

Early weaning in humans compared to Chimps is comensurate with carnivory

Life History

Hunting large game provides 6-10 times higher return than collecting tuber, nuts or any other plant food

Kuhn, S. L., & Stiner, M. C. (2006). What’s a Mother to Do? The Division of Labor among Neandertals and Modern Humans in Eurasia. Current Anthropology, 47(6), 953-981

Ethnography

High yield carnivory is essential to enable support of 20 years of dependency and education of young humans. Gathering plants could not provide enough surplus calories for significant support.

Life History

Inter-disciplinary evidence supportsOne Paleolithic

Highly Carnivorous Diet

Life History

Archaeology

N Isotope

Strontium

Anatomy

Genetics

Animal Behavior

Ethnography

Paleontology

Bacteriology