Read Catching Fire: How Cooking Made Us Human Online
Authors: Richard Wrangham
Tags: #Cooking, #History, #Political Science, #Public Policy, #Cultural Policy, #Science, #Life Sciences, #Evolution, #Social Science, #Anthropology, #General, #Cultural, #Popular Culture, #Agriculture & Food, #Technology & Engineering, #Fire Science
Catching Fire: How Cooking Made Us Human (23 page)
BOOK: Catching Fire: How Cooking Made Us Human
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Two: The Cook’s Body
38
Spontaneous benefits are experienced by almost any species:
Effects of cooked food on farm animals: Mabjeesh et al. (2000), Campling (1991), Pattanaik et al. (2000), Medel et al. (2002), Medel et al. (2004), Nagalakshmi et al. (2003). In cattle there is a limit to this relationship, because cows need a minimal amount of roughage in their diet (Owen [1991]).
Spontaneous benefits are experienced by almost any species:
Effects of cooked food on farm animals: Mabjeesh et al. (2000), Campling (1991), Pattanaik et al. (2000), Medel et al. (2002), Medel et al. (2004), Nagalakshmi et al. (2003). In cattle there is a limit to this relationship, because cows need a minimal amount of roughage in their diet (Owen [1991]).
38
Salmon grow better on a diet of cooked rather than raw fishmeal
: Stead and Laird (2002). Although cooked fishmeal was developed in 1937 and chicken pellets were invented in 1944, the value of cooking has only recently been appreciated by the fish-farming industry. Salmon farming, the most important form of British aquaculture, depends importantly on fishmeal, which provides 20 percent to 35 percent of the worldwide aquaculture foods. The main sources of fishmeal are small oceanic species such as anchovy and sardine. About six million to seven million metric tons of fishmeal were cooked, pressed, dried, and ground annually around the turn of the twenty-first century. In the 1980s, commercial diets in early British salmon farms were cheap because they used a conventional pellet press process without extrusion, in which the temperature of the material rose to a mere 60
o
C-70
o
C (140
o
F-158
o
F) and pellets were cut off after being pushed through a press like bits of pasta. Salmon prices in Britain were high, around £7 per pound, so salmon-farm owners made adequate profits even though the fish grew relatively slowly and fewer survived compared to nowadays. Then the price of salmon began to fall, putting economic pressure on the farmers and making the right food choice more important. Fish-feed manufacturers started to use intense cooking methods, producing extruded feeds. Fishmeal and grain ingredients were pressurized with water and superheated steam at temperatures up to 120
o
C (248
o
F) before being passed through a die under pressure. The increased heat led to more gelatinization of starch and more effective killing of pathogens. The pellets were also puffed up by “flashing off ” of water during the extrusion process, thought to increase digestibility. Although diet may not have been the only contributor to rising success, it accounted for almost half of production costs, so its effectiveness strongly affected profits. With the change in food processing, the industry’s performance improved. During the 1990s, the average weight of harvested fish rose from 2.5 kilograms (5.5 pounds) to almost 4 kilograms (8.8 pounds), survival rose from about 60 percent to 90 percent, and production costs fell.
Salmon grow better on a diet of cooked rather than raw fishmeal
: Stead and Laird (2002). Although cooked fishmeal was developed in 1937 and chicken pellets were invented in 1944, the value of cooking has only recently been appreciated by the fish-farming industry. Salmon farming, the most important form of British aquaculture, depends importantly on fishmeal, which provides 20 percent to 35 percent of the worldwide aquaculture foods. The main sources of fishmeal are small oceanic species such as anchovy and sardine. About six million to seven million metric tons of fishmeal were cooked, pressed, dried, and ground annually around the turn of the twenty-first century. In the 1980s, commercial diets in early British salmon farms were cheap because they used a conventional pellet press process without extrusion, in which the temperature of the material rose to a mere 60
o
C-70
o
C (140
o
F-158
o
F) and pellets were cut off after being pushed through a press like bits of pasta. Salmon prices in Britain were high, around £7 per pound, so salmon-farm owners made adequate profits even though the fish grew relatively slowly and fewer survived compared to nowadays. Then the price of salmon began to fall, putting economic pressure on the farmers and making the right food choice more important. Fish-feed manufacturers started to use intense cooking methods, producing extruded feeds. Fishmeal and grain ingredients were pressurized with water and superheated steam at temperatures up to 120
o
C (248
o
F) before being passed through a die under pressure. The increased heat led to more gelatinization of starch and more effective killing of pathogens. The pellets were also puffed up by “flashing off ” of water during the extrusion process, thought to increase digestibility. Although diet may not have been the only contributor to rising success, it accounted for almost half of production costs, so its effectiveness strongly affected profits. With the change in food processing, the industry’s performance improved. During the 1990s, the average weight of harvested fish rose from 2.5 kilograms (5.5 pounds) to almost 4 kilograms (8.8 pounds), survival rose from about 60 percent to 90 percent, and production costs fell.
39
Biologically Appropriate Raw Food, or BARF:
Palmer (2002) discusses raw food for dogs. BARF diets are touted at
www.barfworld.com/html/barf_diet/barfdiet.shtml
.
Biologically Appropriate Raw Food, or BARF:
Palmer (2002) discusses raw food for dogs. BARF diets are touted at
www.barfworld.com/html/barf_diet/barfdiet.shtml
.
39
Even insects appear to get immediate benefits:
Carpenter and Bloem (2002), Fisher and Bruck (2004), Pleau et al. (2002).
Even insects appear to get immediate benefits:
Carpenter and Bloem (2002), Fisher and Bruck (2004), Pleau et al. (2002).
40
humans have an astonishingly tiny opening:
Our mouths are small partly because our lips create small openings compared to those of other primates. The difference is less when bones are compared. Kay et al. (1998) measured oral cavities in forty-eight human and forty-four chimpanzee skulls. They found that human oral cavities were a little smaller (107 cubic millimeters) than those of chimpanzees (113 cubic millimeters). Data presented on thirty-three primates by DeGusta et al. (1999) allow calculation of oral cavity size in arbitrary units, suggesting that humans have marginally larger mouths than chimpanzees, though small in relation to body weight. Smith and Jungers (1997) summarized body weights. The median wild adult body weight for three subspecies of chimpanzees was 42 kilograms (female) and 46 kilograms (male). For seven human populations ranging from Pygmies to Samoans, the median weights were 53 kilograms (female) and 61.5 kilograms (male). These data indicate that humans weigh 26 percent to 34 percent more than chimpanzees. However, since the measured oral cavities came from European populations, a more realistic estimate of human body weights (from Denmark) is 62 kilograms (female) and 72 kilograms (male). This comparison has humans weighing 48 percent to 57 percent more than chimpanzees. The reason our mouths look particularly small is that they do not project in front of our faces as they do in chimpanzees: our mouths are tucked so much farther back under our skulls that we have more room in them than a look from the outside suggests. Lucas et al. (2006) comment on the effect of cooking on human mouths.
humans have an astonishingly tiny opening:
Our mouths are small partly because our lips create small openings compared to those of other primates. The difference is less when bones are compared. Kay et al. (1998) measured oral cavities in forty-eight human and forty-four chimpanzee skulls. They found that human oral cavities were a little smaller (107 cubic millimeters) than those of chimpanzees (113 cubic millimeters). Data presented on thirty-three primates by DeGusta et al. (1999) allow calculation of oral cavity size in arbitrary units, suggesting that humans have marginally larger mouths than chimpanzees, though small in relation to body weight. Smith and Jungers (1997) summarized body weights. The median wild adult body weight for three subspecies of chimpanzees was 42 kilograms (female) and 46 kilograms (male). For seven human populations ranging from Pygmies to Samoans, the median weights were 53 kilograms (female) and 61.5 kilograms (male). These data indicate that humans weigh 26 percent to 34 percent more than chimpanzees. However, since the measured oral cavities came from European populations, a more realistic estimate of human body weights (from Denmark) is 62 kilograms (female) and 72 kilograms (male). This comparison has humans weighing 48 percent to 57 percent more than chimpanzees. The reason our mouths look particularly small is that they do not project in front of our faces as they do in chimpanzees: our mouths are tucked so much farther back under our skulls that we have more room in them than a look from the outside suggests. Lucas et al. (2006) comment on the effect of cooking on human mouths.
42
this gene, called MYH16:
Stedman et al. (2004). The detailed work on myosin composition in the jaw muscles is restricted to macaques, but apes are assumed to be similar. Much research remains to be done before the timing of the mutation in the MYH16 gene can be decided with confidence. Recent studies suggest that the mutation may be as old as 5.3 million years. If so, the reasons are puzzling.
this gene, called MYH16:
Stedman et al. (2004). The detailed work on myosin composition in the jaw muscles is restricted to macaques, but apes are assumed to be similar. Much research remains to be done before the timing of the mutation in the MYH16 gene can be decided with confidence. Recent studies suggest that the mutation may be as old as 5.3 million years. If so, the reasons are puzzling.
42
Human chewing teeth, or molars, also are small:
Data were kindly given to me by Neil Roach, based on Kay (1975) using teeth of humans twenty-five thousand years old from Predmosti. Soft food leading to small jaws and teeth: reviewed in Lucas (2004), Lieberman et al. (2004). An alternative idea invoking soft foods was proposed by Milton (1993): humans’ small teeth could be adapted to soft fruits. But it is normally thought that soft fruits were less available in human diets during the past two million years, when they had small teeth, than in earlier times, thanks to their commitment to terrestriality and savanna habitats.
Human chewing teeth, or molars, also are small:
Data were kindly given to me by Neil Roach, based on Kay (1975) using teeth of humans twenty-five thousand years old from Predmosti. Soft food leading to small jaws and teeth: reviewed in Lucas (2004), Lieberman et al. (2004). An alternative idea invoking soft foods was proposed by Milton (1993): humans’ small teeth could be adapted to soft fruits. But it is normally thought that soft fruits were less available in human diets during the past two million years, when they had small teeth, than in earlier times, thanks to their commitment to terrestriality and savanna habitats.
42
physical anthropologist Peter Lucas has calculated:
Lucas (2004).
physical anthropologist Peter Lucas has calculated:
Lucas (2004).
43
the stomach is less than one-third the size:
Data are from Martin et al. (1985), based on forty primates and seventy-three mammals.
the stomach is less than one-third the size:
Data are from Martin et al. (1985), based on forty primates and seventy-three mammals.
43
Great apes eat perhaps twice as much by weight per day as we do:
A wild chimpanzee weighing 41 kilograms (90 pounds) eats about 1.4 kilograms (3.1 pounds) of dry weight of food per day (personal observation, Kibale National Park). A Kalahari bushman of the same weight eats a paltry 0.7 kilograms (1.6 pounds)—about half the chimpanzee’s intake: urban raw-foodists eat about the same. Relationship between dry weight of daily food intake and body mass of primates and humans: Barton (1992). Modern urban raw-foodists: Wrangham and Conklin-Brittain (2003). Fiber content: Conklin-Brittain et al. (2002).
Great apes eat perhaps twice as much by weight per day as we do:
A wild chimpanzee weighing 41 kilograms (90 pounds) eats about 1.4 kilograms (3.1 pounds) of dry weight of food per day (personal observation, Kibale National Park). A Kalahari bushman of the same weight eats a paltry 0.7 kilograms (1.6 pounds)—about half the chimpanzee’s intake: urban raw-foodists eat about the same. Relationship between dry weight of daily food intake and body mass of primates and humans: Barton (1992). Modern urban raw-foodists: Wrangham and Conklin-Brittain (2003). Fiber content: Conklin-Brittain et al. (2002).
43
the human small intestine is only a little smaller than expected:
Martin et al. (1985) show the surface area in humans is smaller than 62 percent of forty-two primate species and is 76 percent of the size expected by comparison with seventy-four mammal species. Milton (1999) notes that our small intestine is long relative to the size of our gastrointestinal system. Though this is true, it has not been shown to be long relative to our body weight. So this does not indicate a special adaptation.
the human small intestine is only a little smaller than expected:
Martin et al. (1985) show the surface area in humans is smaller than 62 percent of forty-two primate species and is 76 percent of the size expected by comparison with seventy-four mammal species. Milton (1999) notes that our small intestine is long relative to the size of our gastrointestinal system. Though this is true, it has not been shown to be long relative to our body weight. So this does not indicate a special adaptation.
43
humans have the same basal metabolic rate as other primates:
Leonard and Robertson (1997).
humans have the same basal metabolic rate as other primates:
Leonard and Robertson (1997).
43
the large intestine, or colon, is less than 60 percent of the mass that would be expected:
Martin et al. (1985) found the surface area of the human colon is smaller than in 92 percent of thirty-eight species of primates in relation to body weight and is 58 percent of the expected size compared to seventy-four mammal species.
the large intestine, or colon, is less than 60 percent of the mass that would be expected:
Martin et al. (1985) found the surface area of the human colon is smaller than in 92 percent of thirty-eight species of primates in relation to body weight and is 58 percent of the expected size compared to seventy-four mammal species.
43
The colon is where our intestinal flora ferment plant fiber:
For human reliance on plants, see the consensus noted by Bunn and Stanford (2001), and other chapters in Stanford and Bunn (2001).
The colon is where our intestinal flora ferment plant fiber:
For human reliance on plants, see the consensus noted by Bunn and Stanford (2001), and other chapters in Stanford and Bunn (2001).
44
the volume of the entire human gut:
Calculated from data in Chivers and Hladik (1980) and Milton and Demment (1988), comparing humans to thirty-five primate species. Gut mass 60 percent of expected: Aiello and Wheeler (1995).
the volume of the entire human gut:
Calculated from data in Chivers and Hladik (1980) and Milton and Demment (1988), comparing humans to thirty-five primate species. Gut mass 60 percent of expected: Aiello and Wheeler (1995).
44
a reduction in the size of jaw muscles:
Lucas et al. (2008) propose that jaw muscles are small in humans because the body needs to be accurate in sensing forces when chewing.
a reduction in the size of jaw muscles:
Lucas et al. (2008) propose that jaw muscles are small in humans because the body needs to be accurate in sensing forces when chewing.
44
the reduction in human gut size saves humans at least 10 percent:
Aiello and Wheeler (1995), p. 205.
the reduction in human gut size saves humans at least 10 percent:
Aiello and Wheeler (1995), p. 205.
44
The suite of changes in the human digestive system makes sense:
Wrangham and Conklin-Brittain (2003). Milton (1999), and Stanford and Bunn (2001) reviewed the meat-eating hypothesis.
The suite of changes in the human digestive system makes sense:
Wrangham and Conklin-Brittain (2003). Milton (1999), and Stanford and Bunn (2001) reviewed the meat-eating hypothesis.
45
australopithecines had broad hips and a rib cage:
Aiello and Wheeler (1995).
australopithecines had broad hips and a rib cage:
Aiello and Wheeler (1995).
45
the molars (chewing teeth) of very early humans were somewhat sharper:
Ungar (2004).
the molars (chewing teeth) of very early humans were somewhat sharper:
Ungar (2004).
46
Carnivores such as dogs, and probably wolves and hyenas, also tend to have small guts:
Chivers and Hladik (1980, 1984), Martin et al. (1985), MacLarnon et al. (1986), Milton (1987, 1999). Large guts in australopithecines are indicated by wide flaring of the ribs (Aiello and Wheeler [1995]).
Carnivores such as dogs, and probably wolves and hyenas, also tend to have small guts:
Chivers and Hladik (1980, 1984), Martin et al. (1985), MacLarnon et al. (1986), Milton (1987, 1999). Large guts in australopithecines are indicated by wide flaring of the ribs (Aiello and Wheeler [1995]).
46
Dogs tend to keep food in the stomach for two to four hours, and cats for five to six hours:
Transit times compared between carnivores and primates: Milton (1999). Transit times compared between humans and dogs using same meals (cooked chicken liver): Meyer et al. (1985, 1988). In humans, 50 percent of the meal was emptied from the stomach after approximately 105 minutes; in dogs, 50 percent of the same meal was emptied after approximately 180 minutes. See also Tanaka et al. (1997), Ragir (2000). Cats: Armbrust et al. (2003).
Dogs tend to keep food in the stomach for two to four hours, and cats for five to six hours:
Transit times compared between carnivores and primates: Milton (1999). Transit times compared between humans and dogs using same meals (cooked chicken liver): Meyer et al. (1985, 1988). In humans, 50 percent of the meal was emptied from the stomach after approximately 105 minutes; in dogs, 50 percent of the same meal was emptied after approximately 180 minutes. See also Tanaka et al. (1997), Ragir (2000). Cats: Armbrust et al. (2003).
47
Raw meat might have been usefully pounded:
The idea that a key behavioral adaptation of early humans was the use of tools to process food goes back at least to Oakley (1962). Milton and Demment (1988) suggested that using tools could account for reductions in tooth and gut size in the human lineage. Teaford et al. (2002) proposed that reduction in incisor size could likewise be related to increased use of tools for processing food.
Raw meat might have been usefully pounded:
The idea that a key behavioral adaptation of early humans was the use of tools to process food goes back at least to Oakley (1962). Milton and Demment (1988) suggested that using tools could account for reductions in tooth and gut size in the human lineage. Teaford et al. (2002) proposed that reduction in incisor size could likewise be related to increased use of tools for processing food.
47
It might have been allowed to rot:
Sherman and Billing (2006) discuss the problem of bacterial infection in meat.
It might have been allowed to rot:
Sherman and Billing (2006) discuss the problem of bacterial infection in meat.
48
“If you are transferred suddenly from a diet normal in fat”:
Quote is from Stefansson (1944), p. 234. Stefansson’s years of ethnographic work with the Inuit made him intensely interested in their dietary adaptations, and he conducted several intriguing experiments on himself. Speth (1989) describes how Stefansson lived on meat alone for a year in New York under medical supervision. Mostly his diet was 25 percent protein and 75 percent fat, but he adjusted it to an intake of 45 percent to 50 percent protein for a time. He then experienced nausea, diarrhea, loss of appetite, and general discomfort. He felt better again within two days of returning to the diet of 25 percent protein. For maximum levels of protein, see Speth (1989).
“If you are transferred suddenly from a diet normal in fat”:
Quote is from Stefansson (1944), p. 234. Stefansson’s years of ethnographic work with the Inuit made him intensely interested in their dietary adaptations, and he conducted several intriguing experiments on himself. Speth (1989) describes how Stefansson lived on meat alone for a year in New York under medical supervision. Mostly his diet was 25 percent protein and 75 percent fat, but he adjusted it to an intake of 45 percent to 50 percent protein for a time. He then experienced nausea, diarrhea, loss of appetite, and general discomfort. He felt better again within two days of returning to the diet of 25 percent protein. For maximum levels of protein, see Speth (1989).
49
People with an anatomy like ours today could not have flourished on raw food:
An alternative idea could be that marrow, which requires no chewing, could have been eaten at sufficiently high levels to promote protein- and fat-digesting specializations in the gut while allowing the mouth, jaws, and teeth to be small. However, although marrow may well have been an important component of the diet, it cannot have been exclusive in view of the high frequency of cut marks on the bones of prey animals around the time these features changed in human evolution.
People with an anatomy like ours today could not have flourished on raw food:
An alternative idea could be that marrow, which requires no chewing, could have been eaten at sufficiently high levels to promote protein- and fat-digesting specializations in the gut while allowing the mouth, jaws, and teeth to be small. However, although marrow may well have been an important component of the diet, it cannot have been exclusive in view of the high frequency of cut marks on the bones of prey animals around the time these features changed in human evolution.
50
Take, for example, Maillard compounds:
Vlassara et al. (2002) review health problems associated with these compounds.
Take, for example, Maillard compounds:
Vlassara et al. (2002) review health problems associated with these compounds.
51
The tastes are strong and rich:
Nishida (2000) systematically catalogued the tastes of chimpanzee foods in the Ma-hale Mountains, Tanzania.
The tastes are strong and rich:
Nishida (2000) systematically catalogued the tastes of chimpanzee foods in the Ma-hale Mountains, Tanzania.
53
Even when we cook our meat:
Ragir et al. (2000), Sherman and Billing (2006).
Three: The Energy Theory of CookingEven when we cook our meat:
Ragir et al. (2000), Sherman and Billing (2006).
55
authoritative science flatly challenges this idea:
U.S. Department of Agriculture,
National Nutrient Database for Standard Reference
(2007). McCance and Widdowson’s
The Composition of Foods:
Food Standards Agency (2002). To assess the apparent effect of cooking, I compared calorie densities per dry weight for foods where nutrient data were reported both for the raw and cooked versions. In some cases, minor gains in energy were reported, such as a 1.7 percent increase in the energy density of carrots from being boiled, or a 1.5 percent increase in sirloin after roasting. In others there were minor losses in energy density, such as a 1.8 percent decrease in the energy density of beets after boiling, or a 2.0 percent loss in energy of tenderloin after being roasted. Overall, such cases canceled each other out. When I plotted a graph showing the energy density in cooked foods against the energy density in raw foods, I found that on average, cooked foods were reported to have almost exactly the same energy density as raw foods, regardless of whether they were rich in carbohydrates or protein.
authoritative science flatly challenges this idea:
U.S. Department of Agriculture,
National Nutrient Database for Standard Reference
(2007). McCance and Widdowson’s
The Composition of Foods:
Food Standards Agency (2002). To assess the apparent effect of cooking, I compared calorie densities per dry weight for foods where nutrient data were reported both for the raw and cooked versions. In some cases, minor gains in energy were reported, such as a 1.7 percent increase in the energy density of carrots from being boiled, or a 1.5 percent increase in sirloin after roasting. In others there were minor losses in energy density, such as a 1.8 percent decrease in the energy density of beets after boiling, or a 2.0 percent loss in energy of tenderloin after being roasted. Overall, such cases canceled each other out. When I plotted a graph showing the energy density in cooked foods against the energy density in raw foods, I found that on average, cooked foods were reported to have almost exactly the same energy density as raw foods, regardless of whether they were rich in carbohydrates or protein.
56
“a technological way of externalizing part of the digestive process”:
Aiello and Wheeler (1995), p. 210.
“a technological way of externalizing part of the digestive process”:
Aiello and Wheeler (1995), p. 210.
56 “
fresh premium breakfast sausages”:
made by Shady Brook Farms.
fresh premium breakfast sausages”:
made by Shady Brook Farms.
56
Leading nutritionist David Jenkins:
Jenkins (1988), p. 1156.
Leading nutritionist David Jenkins:
Jenkins (1988), p. 1156.
57
Starchy foods are the key ingredient:
McGee (2004) is an excellent source on the science of cooking. Wandsnider (1997) discusses the chemistry of cooking using hunter-gatherer technology.
Starchy foods are the key ingredient:
McGee (2004) is an excellent source on the science of cooking. Wandsnider (1997) discusses the chemistry of cooking using hunter-gatherer technology.
57
cereals such as rice and wheat made up 44 percent of the world’s food production:
Atkins and Bowler (2001), Table 9.4.
cereals such as rice and wheat made up 44 percent of the world’s food production:
Atkins and Bowler (2001), Table 9.4.
BOOK: Catching Fire: How Cooking Made Us Human
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