Prime Time Replay:
Stanley Ambrose, Ph.D.
on diet and nutrition in prehistoric humans
MsgId: *breakthrough(1)
Date: Wed Dec 10 14:57:59 PST 1997
From: moderator At: 152.163.204.135
Welcome to Breakthrough Medicine. Today I'll be speaking with Stanley Ambrose, Ph.D., of the department of Anthropology at the University of Illinois, Urbana.
MsgId: *breakthrough(2)
Date: Wed Dec 10 15:01:31 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Hello Folks!
MsgId: *breakthrough(3)
Date: Wed Dec 10 15:02:57 PST 1997
From: moderator At: 152.163.204.135
Could we begin by talking about your research on the dietary evidence found in prehistoric bones? Where have you done your work? Which peoples are you studying?
MsgId: *breakthrough(4)
Date: Wed Dec 10 15:05:09 PST 1997
From: Stan-Ambrose At: 128.174.248.147
I have performed stable isotopic analysis of bones and teeth ranging from 14 million years old to modern ones, uncluding mammals and humans. I have also worked on bones from Europe, North America and Micronesia.
MsgId: *breakthrough(5)
Date: Wed Dec 10 15:06:19 PST 1997
From: moderator At: 152.163.204.135
Are there a lot of differences in the bones of ancient people, as compared to more modern ones?
MsgId: *breakthrough(6)
Date: Wed Dec 10 15:07:48 PST 1997
From: Stan-Ambrose At: 128.174.248.147
The fossils degrade through time, losing protein (mainly collagen) and the carbon in the mineral phase of bone (apatite carbonate) may exchange with the burial environment. This is not a problem with tooth enamel, however.
MsgId: *breakthrough(7)
Date: Wed Dec 10 15:08:48 PST 1997
From: moderator At: 152.163.204.135
Can you learn about their diet you do your analysis?
MsgId: *breakthrough(8)
Date: Wed Dec 10 15:10:53 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Yes. I analyze the carbon isotope ratios of the bone (13C/12C) to determine whether they ate marine or terrestrial foods, or tropical grans versus other plant types. The nitrogen isotopes (15N/14N) also differentiate marine and terrestrial and meat from plant. For example, tropical grasses, which include corn (maize), millets and sorghum, have high 13C values, as do wild tropical grasses. By analysis of bones or hair or anything else with carbon, I can tell the proportions of the two major terrestrial plant classes in the diet, so I can differentiate grazers like zebra from browsers like giraffe.Among humans, who live in areas where all of the food resources have low 13C values, I can tell how much corn people ate from their bone 13C values. The bone carbonate values provide a very accurate estimate of the amount of carbon ingested from corn.
MsgId: *breakthrough(11)
Date: Wed Dec 10 15:17:31 PST 1997
From: moderator At: 152.163.204.135
Can you tell about disease from your research?
MsgId: *breakthrough(12)
Date: Wed Dec 10 15:19:43 PST 1997
From: Stan-Ambrose At: 128.174.248.147
This method can be used to tell very little about health directly, but it can be used to help identify possible nutritional sources of long-term chronic conditions that may leave traces on the skeleton. For example, a diet with little protein may lead to anemia, which then leads to specialized forms of osteoporosis in parts of the skeleton, especially around the face and eye sockets. This condition is called cribra orbitalia. Corn actually depletes iron stores (I don't know why). If the skeletons that show this specialized form of iron-deficiency anemia have very high 13C values, then the specialized diet with imbalanced nutrients, such as one would get with corn, is the likely cause of anemia.
MsgId: *breakthrough(15)
Date: Wed Dec 10 15:25:43 PST 1997
From: moderator At: 152.163.204.135
As you cross millions of years, in the same location, do you see changes in diet, or health correlations?
MsgId: *breakthrough(16)
Date: Wed Dec 10 15:29:07 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Millions of years is a long time with many tales to tell, so I'll just concentrate on the hunter-gatherers of the last ice age and the early farmers. During the last ica age, big game hunters (giant bison, mammoths, etc) were favored prey. People were very tall and strong. These Cro-Magnon types seem to have had nutritional stress around the time they ate solid foods. This is shown by growth defects in the tooth enamel of teeth that formed during weaning. The stress is largely due to infections and diarrheah as solid foods are introduced and babies mouth everything.The tooth defects are known as "linear enamel hypoplasias". What is really interesting is that neanderthals who lived in the same ice age environemnts, had hypoplasias throughout tooth enamel formation, which ends around 12 years after birth. Modern humans and neanderthals had much different patterns of stress.
MsgId: *breakthrough(19)
Date: Wed Dec 10 15:38:52 PST 1997
From: moderator At: 152.163.204.135
Are the differences between people in the ice age obvious from these different findings? Can you make any conclusions from these skeletons?
MsgId: *breakthrough(20)
Date: Wed Dec 10 15:42:44 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Most of the work on reconstructing ice age behavior differences between humans and neanderthals has been done by Eric Trinkaus (Wash. U., St. Louis). He has shown neanderthals lived by brute force. We believe they had poorer abilities to find and store food (if they did store it) and were ineffective hunters. I am trying to use stable nitrogen isotope analysis to determine if the neanderthals ate more plants than modern humans in Europe. Only two neanderthals have been analyzed and I have not begun analysis of Cro-Magnon fossils. I hope they are different. So far, the isotopic composition of neanderthals is carnivore-like.
MsgId: *breakthrough(22)
Date: Wed Dec 10 15:47:10 PST 1997
From: moderator At: 152.163.204.135
What are the dietary differences between hunter-gatherers and early farmers?
MsgId: *breakthrough(23)
Date: Wed Dec 10 15:50:45 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Ice age hunters were on average 7 inches taller than prehistoric farmers. Much of the difference can be attributed to two factors: First, lower diet quality, meaning fewer food types were eaten, and often very little animal protein. Second, higher frequencies of illness, from overcrowding, polluted water and poorer nutrition.
MsgId: *breakthrough(24)
Date: Wed Dec 10 15:53:55 PST 1997
From: moderator At: 152.163.204.135
Do you ever see evidence of natural medicine sources in the bones?
MsgId: *breakthrough(25)
Date: Wed Dec 10 15:57:36 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Ancient Nubian farmers sometimes show flourescent lines in their bone and tooth microstructure. This can occur when tetracycline and other antibiotics are consumed. Different antibiotics even flouresce in different colors. They may have intentionally eaten stored wheat infected by pennicillin molds.
MsgId: *breakthrough(26)
Date: Wed Dec 10 15:59:53 PST 1997
From: moderator At: 152.163.204.135
What are the most striking dietary differences you've seen?
MsgId: *breakthrough(27)
Date: Wed Dec 10 16:02:29 PST 1997
From: Stan-Ambrose At: 128.174.248.147
I analyzed skeletal populations from three islands in Micronesia: Guam, Rota and Saipan. The bone carbonate of the Saipan people showed extremely high levels of a 13C-rich plant food, but the archaeologists and anthropologists could not tell me what it was. After digging into the literature I found one possibility.The food source had to be one with no protein because it did not affect the nitrogen isotope values. The food source that best fits this description is sugar cane. The ethnohistoric literature seems to show that sugar cane was a staple food crop until 200 years ago, when it was replaced by sweet potatos. In NewGuinea, where sugar cane was domesticated over 45000 years ago, they also fed sugar cane scraps to the pigs. The meat was described as sweet and tender! The archaeologists did not like my conclusions at first, but the teeth of Saipan people had 3 times more cavities than those from Guam and Rota.
MsgId: *breakthrough(30)
Date: Wed Dec 10 16:09:06 PST 1997
From: moderator At: 152.163.204.135
Why did they switch to sweet potato?
MsgId: *breakthrough(31)
Date: Wed Dec 10 16:10:17 PST 1997
From: Stan-Ambrose At: 128.174.248.147
I think that they could get more starch per acre from sweet potato and it probably depletes the soil less than sugar cane. Most grasses, like sugar cane prefer more fertile soils. Tubers do well on poor soils.
MsgId: *breakthrough(32)
Date: Wed Dec 10 16:11:04 PST 1997
From: moderator At: 152.163.204.135
Have you ever seen dietary differences reflecting different status in a social group?
MsgId: *breakthrough(33)
Date: Wed Dec 10 16:13:33 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Yes. In East St. Louis Illinois, is the largest prehistoric man-made structure, at the site called Cahokia. There are about 100 mounds of different sizes, as well as astronomical features, villages, etc. It was a large ceremonial and trade center. Mound 72 had about 240 individuals buried in it. One male was buried on a bed of 17,000 marine shell beads. Several other males were also associated with high status items such as copper sheets, piles of arrowheads and fancy game stones. There were also large pits with dozens of young females - aged 20-25, many with lots of cavities and osteoporosis.The high status males and apparently sacrificial females had very different carbon and nitrogen isotope ratios. The males apparently ate a lot of meat and a small amount of corn. The females had very low nitrogen isotope ratios, indicating little animal protein, and very high 13C, indicating they ate 5-% more corn than the males. The low-status females apparently ate 50-60% more corn than the males.
MsgId: *breakthrough(37)
Date: Wed Dec 10 16:22:35 PST 1997
From: moderator At: 152.163.204.135
After what you've discovered about diet, do you have any recommendations for a modern diet?
MsgId: *breakthrough(38)
Date: Wed Dec 10 16:25:28 PST 1997
From: Stan-Ambrose At: 128.174.248.147
I think that overspecialized, narrow, low-protein diets should be avoided if you want to grow strong, tall and healthy. Animal protein fulfills many nutritional requrements, but a very diverse vegetarian diet with lots of grains and legumes works well. Just don't eat too much of one kind of plant staple.
MsgId: *breakthrough(39)
Date: Wed Dec 10 16:26:05 PST 1997
From: moderator At: 152.163.204.135
Thank you for joining me today on Breakthrough Medicine.
MsgId: *breakthrough(40)
Date: Wed Dec 10 16:27:25 PST 1997
From: Stan-Ambrose At: 128.174.248.147
Thanks very much for inviting me to talk about paleodietary research. I hope your subscribers find it interesting.
MsgId: *breakthrough(41)
Date: Wed Dec 10 16:34:07 PST 1997
From: moderator At: 152.163.204.135
Please join me next week when I speak with William Calvin, neurophysiologist at the University of Washington, Seattle, who will discuss his work and two of his books, "The Cerebral Code," and "How Brains Think."
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