Written by: Lauren Milligan Newmark, Ph.D. | Issue # 132 | 2026
- Milk consumption and processing by prehistoric populations can be identified from ancient milk lipids trapped in ceramic vessels and ancient milk proteins stuck inside dental tartar.
- Ancient lipids and proteins from Neolithic excavations in the Zagros Mountains of Iran indicate these populations were consuming either goat or sheep milk by 8,000 years ago with the earliest direct evidence closer to 9,000 years ago.
- Mortality patterns from animal bones at the archaeological sites demonstrated that goats were the first ruminants used for dairy in the Zagros Mountain region.
- Both sedentary agricultural populations and mobile pastoral people were exploiting goat milk during the early Neolithic, but the earliest milk drinkers in that region may date back to nearly 10,000 years ago.
Most people would find food-crusted bowls and tartar-covered teeth disgusting. But one person’s grime is another’s gold mine. Archaeologists interested in reconstructing human diets delight in discovering prehistoric dirty dishes and unbrushed human teeth because they are incredible archives of ancient meals. Fat residues stuck in porous ceramic surfaces and proteins trapped within the sticky matrix of dental tartar can be matched to their food source, allowing researchers to determine what a population was cooking and consuming thousands of years ago.
These culinary fossils have been particularly useful in reconstructing the origins of dairying. Milk fatty acids have a unique chemical signature that distinguishes them from fatty acids from an animal’s body fat. Milk also contains unique proteins, specifically casein proteins and the whey protein alpha-lactalbumin, that are only synthesized by mammary glands. Identification of these fats or proteins trapped in ancient vessels or on teeth provides direct evidence of the exploitation of dairy foods, sometimes even allowing researchers to pinpoint which species provided the milk and to radiocarbon date the fat residues. It’s the next best thing to having a time-stamped photo of a prehistoric person drinking from a labeled carton of milk!
A new study [1] applied these cutting-age biochemical and radiocarbon techniques to ceramic and human remains excavated from nine Neolithic sites across the Zagros Mountains in the Iranian Plateau. This area was of interest to archaeologists as a possible site of early dairy culture because it is a known center for goat domestication. While many populations in the Near East focused on cattle domestication, the rugged terrain and the arid climate of the Zagros favored goats and sheep who required less water and could graze on steep terrain [2]. The Neolithic peoples of the Iranian Plateau were also a source population for the eastward spread of agropastoralism, a mode of subsistence that combines crop cultivation with raising livestock [1]. The faunal (nonhuman animal) fossil assemblages at the sites around the Zagros were dominated by both goats and sheep (together referred to as caprines), accounting for 94% of the total animal bones. But whether these caprines were used for milk, meat, or both was unknown.
The nine archaeological sites ranged in age from approximately 9,000 to 5,000 years ago and were either permanent settlements, open-air campsites for mobile pastoralists, or seasonal cave campsites of pastoralists [1]. Ancient proteins were extracted from the tartar on the teeth of ten individuals from the permanent sites, and 368 pottery fragments from across the sites were analyzed for lipid residues. Of these fragments, only 15 demonstrated biochemical evidence of ruminant fat, providing a total of 161 lipid extracts for analysis [1]. To determine whether the fat source was from the body or milk, the team compared the stable isotope composition of two medium chain fatty acids (stearic and palmitic acid) to caprine body fat and caprine dairy products. Sixty-five of the 161 lipid extracts had isotopic values characteristic of ruminant milk whereas 87 had isotopic values characteristic of ruminant body fat [1]. Importantly, all but one site (the cave site of Mar Suchar) provided ceramics with ruminant dairy fat residue, suggesting that consumption of ruminant milk was widespread in this region and not only associated with permanent settlements.
Milk proteins were harder to detect, but nonetheless still identified. Of the ten individuals whose teeth had tartar samples, three had evidence for milk casein proteins in appreciable quantities and six had casein proteins at lower quantities [1]. Milk alpha-lactalbumin was not detected in any individual’s tartar. The specific molecular structure of the casein protein chains from three individuals allowed researchers to move beyond describing their finds as “ruminant” milk and determine that the source of the milk was a species from the genus Ovis (sheep) or Capra (goats) [1].
Data from the protein and lipid residue analyses suggest that caprine milk was indeed on the menu for both permanent and mobile Neolithic populations of the Iranian plateau. The next question to address was when these populations were consuming milk. The research team performed direct carbon-14 (14C) dating on dairy fat residues from ceramics across the nine sites and found that the earliest ruminant dairy fats dated to approximately 7,000 years ago from the Wezmeh cave site [1]. Additional ceramic fragments from this site with ruminant body fat were dated to approximately 4,700 years ago indicating over 2,000 years of seasonal occupation by pastoral populations that exploited caprine species, and presumably caprine milk [1].
This wasn’t necessarily the earliest exploitation of caprine milk, simply the earliest evidence for milk processed on ceramics. Importantly, one of the individuals whose dental tartar was found to contain milk casein proteins was from the East Mound at the site of Sang-e Chakhmaq. Individuals excavated from this mound are associated with the time period known as the Pre-Pottery Neolithic, ca. 8,500 years ago. This individual provided the earliest direct evidence for dairy consumption in the Iranian plateau [1].
The research team had one more tool at their disposal to complete the picture of dairy exploitation in the Zagros Mountains. Mortality patterns (age at death) from the faunal assemblages could help distinguish whether the earliest milk exploitation was from sheep or goats, something the biochemical analyses were unable to determine. Evidence for an emphasis on dairy over meat would be a high proportion of female adults, particularly older females, compared with male adults and a lower mortality of juveniles who would be maintained for reproduction (which is required for milk production) rather than killed at a prime age for meat consumption. The mortality profiles at the site of Qale Rostam strongly suggested that goats were raised for milk before sheep [1]. Faunal data were not as precise at other sites, so it can’t be said with certainty that goats were the earliest dairy animals throughout this region, although it seems likely considering their earlier domestication (ca. 9000 years ago) in this region [1].
Using multiple lines of evidence, this study [1] found that by 8,000 years ago, both sedentary and mobile populations living in the Zagros Mountains on the Iranian Plateau were raising goats for milk, with the earliest known consumption dating to nearly 9,000 years ago. These findings match the earliest dates for evidence of cow milk consumption in nearby Anatolia [3] (modern day Turkey), suggesting independent but synchronous development of dairy culture of different ruminant species by these two neighboring populations [1].
These are the earliest dates for direct consumption of dairy anywhere in the world. But were these the earliest milk consumers in the Zagros Mountain region? The researchers don’t think so. Instead, they argue that the earliest milk drinkers in the Zagros will be found in archaeological assemblages associated with the Pre-Pottery Neolithic. As the name suggests, these prehistoric populations were not associated with ceramics, making it impossible to study lipid residues from their past meals. But fossilized animal bones and tartar stuck on teeth would still be part of these archaeological assemblages and should be examined for evidence of mortality patterns and proteins associated with dairy consumption [1]. They’ve already identified one milk drinker in this population– could this person’s great, great (great, great) grandparents be the first milk drinkers in the Iranian Plateau? Hopefully they didn’t brush their teeth!
References
- Casanova E, Davoudi H, Zazzo A, Zirah S, Jacob J, Hatté C, Boco-Simon A, Thil F, Gauthier C, Nokandeh J, Alizadeh A. Caprine dairy exploitation on the Iranian Plateau from the seventh millennium BC. Nat Hum Behav. 2026 Feb 9: 1-1.
- Zeder MA, Hesse B. The initial domestication of goats (Capra hircus) in the Zagros mountains 10,000 years ago. Science. 2000 Mar 24;287(5461): 2254-7.
- Özbal H, Breu A, Thissen L, Gerritsen F, van den Bos E, Galik A, Doğan T, Çergel M, Şimşek A, Türkekul A, Özbal R. From bowls to pots: The dairying revolution in Northwest Turkey, a view from Barcın Höyük, 6600 to 6000 BCE. PloS One. 2024 May 9;19(5): e0302788