Ancient Human Hair May Be Key To Understanding Diet Of Ancient Civilizations

Macko has recently analyzed hair clippings from the Neolithic Ice Man of the Oetztaler Alps; the Coptics of Egypt; the Late Middle Kingdom mummies of Egypt; and the Chinchorro mummies of Chile.

He has found that the Ice Man -- thought by some to be a hunter -- was probably a very strict vegetarian at the time of his death. "There's little indication of meat consumption," Macko says. The Coptics of Egypt, like the Chinchorro of Chile, ate a wide variety of vegetables, grains, meats, seafood and dairy products, "sort of like the modern-day supermarket diet," Macko says. The Late Middle Kingdom Egyptians, on the other hand, appear to have eaten a somewhat restricted diet with more animal products. "It seems that the upper-class of the time, perhaps for some sociological reason, had a much less diverse diet than was available to them," Macko says.

He will present his findings Oct. 26 at the annual meeting of the Geological Society of America in Toronto.

"Ancient hair is chemically little different from the hair that's swept up each day from the barbershop floor," Macko says. "Unlike bones and flesh which decay and change chemically, hair seems to stay the same. It is a terrific archive of information about the nutrition of ancient peoples."

Until Macko began analyzing ancient hair a couple of years ago in his stable isotope laboratory at U.Va., few had thought to use hair for nutrition studies of ancient civilizations.

"Researchers generally look to artifacts found at archeological sites to make intelligent guesses about the dietary habits of ancient people," Macko says. "As geochemists, we are providing a different perspective for the archaeologists. We are using sophisticated laboratory techniques to analyze hair, which may be the best preserved part of the human body."

Macko obtains his data by measuring the isotopes in organic materials. By observing changes in abundances of carbon, nitrogen or sulfur, he can differentiate source materials, whether plant or animal and terrestrial or marine.

"We cannot tell what kind of bread a person ate, but we can determine if they ate grains, or meat or fish or vegetables. There is a great deal we can explain about a person's diet through hair. Nature has done the work for us by storing this information in the material. We simply measure it. This is basically a forensic technique, performed on ancient people."

Though trained as an organic geochemist, Macko says he has developed an interest in the people whose hair he has analyzed, and in their stories. "It is fascinating to speculate on their lives based on what we are learning about their diets."

He gives the Chinchorro of Chile as an example. "We have found a strong marine component in the diet of a population that lived well inland in the Atacama desert," he says. "This indicated a level of interaction between the coastal and inland populations that previously was not recognized. We also have indications that Egyptian Late Middle Kingdom royalty ate a fairly constrained diet. This is new information for the archaeologists to use in their study of ancient peoples."

Macko first became interested in human diet and nutrition years ago when he began analyzing fingernail clippings from his graduate students. "I've had some students say they are strict vegetarians, but after analyzing their fingernails, we found evidence of eggs, fish, dairy or even meat consumption. Then they admit, they're not living only on vegetables. Our data was telling the truth."